Maintaining A Balance

Transcription

1 Maintaining A Balance

2 1.Mst rganisms are active in a limited temperature range Randm ntes Hmestasis cnstant internal balance 37 degrees is gd 39 degrees is fever 35 degrees is hypthermic The bdy strives t achieve hmestasis fr the sake f enzymes Hmestatic mechanisms attempt t keep the bdy at the right temp T ht sweating, red (capillaries dilating), thirsty T cld shivering (muscles mve generates heat) A cntrl in an experiment is needed t prve that the experimental variable is the catalyst fr the result that was prduced Istnic: The slutins being cmpared have equal cncentratin f slutes. Hypertnic: The slutin with the higher cncentratin f slutes. Hyptnic: The slutin with the lwer cncentratin f slutes. identify the rle f enzymes in metablism, describe their chemical cmpsitin and use a simple mdel t describe their specificity n substrates Rle = functin Describe = mre detail required Substrate = what the enzyme acts n The rle f enzymes in metablism Enzymes Enzymes are special large prtein mlecules that regulate an rganism and the rate f its chemical activity/reactins Enzymes are bilgical catalysts i.e. they cntrl the rate f a reactin (they slw dwn r speed up a reactin) Nt chemically changed by the reactin, but adjust their shape slightly After the reactin, they release the prduct and return t its riginal frm Enzymes are specific which means they cntrl nly ne reactin each The mlecules n which they act are knwn as substrates Enzymes wrk by prviding an active site where a reactin can take place. Type and amunt f enzymes depends n cell activity Manufacture cntrlled by nucleus, made by ribsmes Only needed in small quantities as they are just catalysts, nt diminished in reactin Inactive at lw temps, denature at high temps Metablism All the chemical prcesses ccurring within an rganism are called metablism

3 Describe their chemical cmpsitin Since enzymes are prteins, they are cmprised f chains f amin acids/plypeptides. Chemically they cntain CHON CHON = Carbn, hydrgen, xygen and nitrgen A simple mdel t describe the specificity n substrates Scientists mdel prcesses t visually represent an idea, making an explanatin easier The lck and key mdel implies that a specific enzyme fits a specific substrate The traditinal mdel t explain enzyme activity is knwn as the lck and key mdel Based n the idea that an enzyme fits a specific substrate and allws the reactin t take place Has been mdified t the current mdel knwn as induced fit mdel Implies that the presence f the substrate in ideal/ptimum temp. and ph induces the enzyme t change shape slightly, allwing the reactin t take place Came abut as a result f experimental wrk that shwed that ptimal temp. is required fr a reactin t take place identify the ph as a way f describing the acidity f a substance ph is a measure f the acidity (and alkalinity, basic) f a slutin. ph represents cncentratin f hydrgen ins in a substance Strng acid Weak acid Weak base Strng base

4 explain why the maintenance f a cnstant internal envirnment is imprtant fr ptimal metablic efficiency All enzymes wrk best under certain cnditins i.e. ptimum cnditins. Hmestasis are thse prcesses that aim t maintain ptimal envirnmental cnditins fr the enzymes t wrk Maintaining ptimal cnditins allws ptimal metablic efficiency This requires the rganism t crdinate internal and external signals and adjust the cmpsitin f the internal bdily fluids t remain within required limits EXAMPLE // ideal bdy temperature is 37 degrees, if the bdy temperature drps tw degrees the bdy is said t be hypthermic. Increase f tw degrees and the bdy is said t be in fever describe hmestasis as the prcess by which rganisms maintain a relatively stable internal envirnment Hmestasis is the prcess by which rganisms maintain a relatively cnstant r stable internal envirnment fr bdy cells. explain that hmestasis cnsists f tw stages: detecting changes frm the stable state cunteracting changes frm the stable state Hmestasis cnsists f tw stages 1. Detecting changes frm the stable state 2. Cunteracting changes t return t the stable state Stimulus is any infrmatin which prvkes a respnse; special receptrs detect stimuli EXTERNAL STIMULI // light, sund, vibratin, temperature, texture, dr INTERNAL STIMULI // levels f CO 2, xygen, water, waste, temperature The stimulus respnse mdel example 1. Stimulus EXAMPLE // increase CO 2 levels in bld 2. Receptr: rgans r tissues that detect change EXAMPLE // chemreceptrs in hypthalamus in brain 3. Cntrl center (central nervus system) EXAMPLE // brain 4. Effectr: muscle r rgans that cunteract the stimulus EXAMPLE // muscles in the chest increase breathing rate 5. Respnse: change in the stimulus EXAMPLE // decreased CO 2 levels in bld Hmestatic rganisms maintain a feedback system i.e. the respnse alters the stimulus. Feedback can be negative i.e. where the stimulus is reduced Or psitive i.e. where the stimulus is increased utline the rle f the nervus system in detecting and respnding t envirnmental changes The human nervus system is made f up f

5 the CNS i.e. the brain and spinal crd the peripheral nervus system - a system f nerves cnnecting receptrs and effectrs, they pass messages t and frm the CNS rapidly The nervus system acts as a cmmunicatin channel between receptrs and effectrs. They detect the stimulus, decide n the respnse required and bring abut that respnse. PROCESS: Receptr cells detect changes t the STABLE STATE. These cells generate nerve impulses which travel alng the sensry nerves t the CNS The CNS determines the apprpriate respnse The CNS sends nerve impulses alng the mtr nerves t effect cells/muscles Therefre, the nervus system regulates and maintains the rganism s internal envirnment by respnding t changes in the external envirnment identify the brad range f temperatures ver which life is fund cmpared with the narrw limits fr individual species Temperatures n land vary much mre than in water The ples can reach temperatures f -70 degrees, whilst the deserts can reach 50 degrees The temperature f the envirnment is knwn as the ambient temperature Organisms must be able t live within the temperature range f their lcal envirnment, as well as daily and seasnal changes Mst species can tlerate a narrw temperature range EXAMPLE // sugar cane needs a warm, frst free envirnment f 15+ degrees Ecttherms Have limited cntrl ver their internal temperature Their bdy temperature rises and falls with the ambient temperature EXAMPLE // fish, all invertebrates, amphibians, reptiles Endtherms Bdy metablism generates heat Internal temperature is independent f external temperature T d this takes energy, s mre fd is required by endtherms cmpare respnses f named Australian ectthermic and endthermic rganisms t changes in the ambient temperature and explain hw these respnses assist temperature regulatin Behaviural adaptatins Migratin: animals mve t avid temperature extremes EXAMPLE // birds spend spring and summer in suth-eastern Australia and migrate t suth-east Asia when the weather turns cld Hibernatin: sme animals remain in a sheltered spt, slwing their metablism and drpping their temperature (endtherms) t survive lng cld cnditins Aestivatin is used fr animals that hibernate in ht cnditins EXAMPLE // Bgng mth migrates t spend the summer mnths in caves in the Australian alps Shelter: animals may seek shelter by burrwing, sheltering in caves, crevices t escape high temperatures during the day and cld at night

6 EXAMPLE // central netted dragn climbs int trees t avid ht cnditins Cntrlling expsure: endtherms may huddle tgether t reduce heat lss EXAMPLE // penguins huddle in crwds Ncturnal activity: when the daily temperature is ht, sme rganisms hunt at night EXAMPLE // hpping mice dig burrws and are active and feed at night Structural and physilgical adaptatins f endtherms Insulatin: fur, feathers r subcutaneus fat act as an insulating layer that slws dwn heat exchange with the envirnment. EXAMPLE // dmestic cats grw a winter fur and lse it in the summer Metablic activity: endtherms generate heat as a result f metablic activity EXAMPLE // shivering increases muscle activity and prduces heat Cntrl f bld flw: endtherms increase r decrease bld flw t the skin and its rute Cunter-current exchange: bld vessels leading t and frm the extremities f the bdy (e.g. legs and tail) are placed tgether and chilled bld returning in the veins picks up heat frm the arteries ging t the extremities EXAMPLE // seal fins Evapratin: endtherms cntrl the rate f evapratin f water frm their bdies EXAMPLE // kangars lick their frearms in ht weather; their frearms have a gd bld supply and when misture evaprates frm them it cls the frearms and thus the bld identify sme respnses f plants t temperature change Death and grwth Plants respnd t temperatures by Altering grwth rate Active plant grwth ccurs within 5-45 degrees in temperate regins In trpical areas, grwth ceases at 15 degrees Dying but leaving drmant seeds with thick prtective cats Dying abve grund Results in rts, rhizmes, bulbs r tubers being left behind that sprut in favurable cnditins Develpmental respnses Temperature change can cntrl develpmental changes in a plant s life cycle, frm germinatin t flwering t seed dispersal

7 EXAMPLE // high Australian temperatures during flwer frmatin prduces pr wheat crp, because pllen frmatin in the anthers is very temperature-sensitive Extremes Vernalisatin is the prcess by which sme plants nly flwer when expsed t cld EXAMPLE // hyacinths, daffdils In sme plants, seed dispersal is stimulated by extreme heat r fire EXAMPLE // banksia trees bear fruit with hard wdy cases, fire stimulates the fruits t pen and seeds are released Leaf adaptatins Leaves may be EXAMPLE // frst-resistant, frst causes camellia leaves t turn transparent, and return t nrmal in warm temp. EXAMPLE // reflective (silvery, waxy r shiny), which reduces the amunt f heat absrbed and keeps the plant cl EXAMPLE // arranged t reduce surface area expsed t sunlight, the Eucalyptus leaves hang vertically EXAMPLE // reduce transpiratin in the httest part f the day t cnserve water identify data surces, plan, chse equipment r resurces and perfrm a first-hand investigatin t test the effect f: increased temperature change in ph change in substrate cncentratins n the activity f named enzyme(s) Enzymes wrk ptimally at a specific temperature, ph and substrate cncentratin Enzymes are specific t a reactin Rennin is an enzyme that causes milk t slidify; it naturally ccurs in the stmach f newbrn cws Increased temperature SUBSTRATE: Milk ENZYME: Rennin, tablet r liquid frm VARIABLE: temperature Aim: t bserve the effects f an enzyme (rennin) n milk Materials: tw test tubes, beaker (fr water bath), ht plate, milk, enzyme sample Methd: 1. Drp 5 drps f enzyme int ne test tube 2. Pur 5ml f milk int each test tube (ne w/ enzyme is yur cntrl) 3. Place in water bath 4. Heat water bath n ht plate t 40 degrees 5. Repeat and heat t 70 degrees 6. Repeat and cl t 10 degrees 7. Recrd bservatins Results: Temp (degrees) Effect n milk (tube with enzyme) 10 N change, just cld 40 Slidified int chunky hard sludge

8 70 Smth, shiny sludge, pached egg cnsistency, denatured the enzyme (curdled, brke dwn) Cnclusin: When the temperature is t lw, the enzyme is nt activated. When the temperature is t high, the milk denatures. When the temperature was at the ptimal temperature f 40 degrees, the milk slidified due t the enzyme creating a site fr the reactin t take place n. Change in ph SUBSTRATE: hydrgen perxide ENZYME: catalase within ptat VARIABLE: ph acid, base and water catalase 2H 2O 2 O 2 + 2H 2O (this is a balanced equatin) the substrate (hydrgen perxide) is changed by the enzyme Catalase is fund in mst living things including ptat Bubbles and frth is prduced as the hydrgen perxide is brken dwn int xygen and water Aim: t determine the effect f ph n milk Variables: Ptat slices shuld be same size Vlume f H 2O 2 shuld be same Methd: 1. Place ph indicatr int test tubes with acid (hydrchlric acid), base (sdium hydrxide) and distilled water, and bserve it turn apprpriate clur red fr acid purple fr base green fr water 2. Place slice f ptat in test tubes 3. Pur 5ml f hydrgen perxide int each. Observe reactins Results: Acid nthing, little bit f fizz and bubble, in ther grups webby bubbles Base little bit f fizz Distilled water effervescent, turned range and then pale green, fizzing excessively, famy white bubbles OR 1. In three test tubes, pur equal amunts f milk 2. Add an acid, a base and distilled water t ne each 3. Test substances with indicatrs 4. Drp 5 drps f rennin enzyme int each test tube Change in substrate SUBSTRATE: milk ENZYME: rennin VARIABLE: substrate

9 The substrate is the cmpnent that the experiment is wrking n, in this case it is the milk Varying the cncentratin f the substrate Variables Place all test tubes in water bath t achieve equal temperature (ideally, 37 degrees) Methd: 1. In first test tube, pur 100% milk 2. In secnd test tube, pur 75% milk diluted with water 3. Third, 50% and furth 25%, fifth 0% (cntrl) 4. Drp 5 drps f rennin int each test tube Results? The line plateaus despite increased substrate cncentratin due t all active sites being ccupied I wuld assume after abut 50% cncentratin the rate f reactin wuld begin t plateau, frth heights being highest at abut 50% Change in surface area Methd: 1. Pur distilled water 5ml int 3 test tubes 2. Cut three pieces f ptat int same length width size etc. 3. Cut piece in half, ne piece in quarters and ne piece in sixths 4. Place pieces in each test tube 5. Add hydrgen perxide t each tube 6. Observe reactins Results: Sixth heaps f bubbles, lads f white famy stuff Quarters lts f bubbles Halves nt many bubbles Cnclusin: the mre surface area the substrate has t wrk n, the mre active sites there are available gather, prcess and analyse infrmatin frm secndary surces and use available evidence t develp a mdel f a feedback mechanism Organisms receive infrmatin frm varius parts f their bdies and envirnment in the frm f stimuli Stimuli is detected by receptrs and results in a respnse frm an rgan r cllectin f rgans Stimulus desn t affect the rgan directly but rather respnses ccur as a result f transmissin thrugh the nervus r endcrine systems EXAMPLE // during exercise, increased respiratin in the muscle cells increases CO 2 in the bld. This is detected by a center in the brain which sends mre frequent nerve impulses t the muscles in yur chest and diaphragm s they cntract mre and breathing increases. CO 2 levels fall

10 twards nrmal. When yu stp exercising, the muscles stp creating excess CO 2, the brain stps sending impulses and breathing slws dwn Stimulus respnse mdel using the example f ht water in a husehld likened t hmestasis FEEDBACK change in tank water temperature STIMULUS - reductin in tank water temperature RESPONSE - heater heats up tank RECEPTOR - thermstat senses drp in water temperature EFFECTOR - heater TRANSMISSION/CONTRO L CENTRE - electric current in wires transmits inf t heater FEEDBACK MECHANISM: Bld temperature its regulatin by the bdy [DOCUMENT OF DIAGRAM IN BIOLOGY FOLDER[ analyse infrmatin frm secndary surces t describe adaptatins and respnses that have ccurred in Australian rganisms t assist temperature regulatin Changes in the ambient temperature Respnses f Ectthermic rganism Eastern blue tngue lizard Increased temperature Mves int the shade f trees and bushes Burrws Reduces cellular activity t reduce little heat internally prduced Cme ut at night Decreased temperature Brumatin hibernatin f cldbld animals, slw metablism, cnserve energy and heat, hides in a hibernaculum fr mnths n end and Respnses f Endthermic rganism the fairy penguin Feathers lay flat against skin, trapping less air Mve int cld waters Overlapping penguin feathers are shed in water and n land Feathers help t sme degree lifted away frm skin, erect, trapping air Layer f subcutaneus fat insulates against cld and prevents heat

11 rarely mves, becme extremely lethargic Flattens self ut in sunlight t increase surface area and heat taken in lss, traps a layer f air clse t the skin Dig deep burrws in castal sand dunes Huddle tgether in crwds t decrease surface area each penguin is expsed t Muscle which cntrl feet and flippers are lcated within the bdy, whilst feet and flippers are cntrlled by tendns, therefr when feet r flippers get cld they are still peratinal via the muscles Heat exchange bld flw, warm bld entering feet flws past cld bld, warming it up 2. Plants and animals transprt disslved nutrients and gases in a fluid medium identify the frm(s) in which each f the fllwing is carried in mammalian bld: carbn dixide xygen water salts lipids nitrgenus waste ther prducts f digestin Substance Frm T Frm Carried by Hw des it change Oxygen Lungs Bdy cells Oxyhaemglbin Red bld cells Refer t 2.4 Carbn dixide Waste nitrgenus material Water Salts Bdy cells Lungs Hydrgen carbnate ins Red bld cells and plasma Liver and Kidneys Mstly as urea Plasma bdy cells Digestive system and bdy cells Digestive system and bdy cells Bdy cells Water mlecules Plasma Bdy cells Ins Plasma

12 Lipids Other prducts f digestin Digestive system Digestive system and liver All cells Bdy cells Glycerl and fatty acids As separate mlecules e.g. glucse and amin acids Prteins in plasma/mlecules called chylmicrns Plasma explain the adaptive advantage f haemglbin Hemglbin is the prtein mlecule in red bld cells that carries xygen frm the lungs t the bdy's tissues and returns carbn dixide frm the tissues back t the lungs. Mammalian cells need a cntinual supply f xygen fr respiratin Oxygen diffuses acrss capillary membranes In the lungs, xygen is added t the bld supply and transprted t tissues where the xygen is unladed frm the bld int the cells Oxygen is nt very sluble in water and the plasma alne can nly carry 0.2 ml f xygen per 100mLs f bld Majrity f xygen is carried attached t haemglbin fund in RBC Each haemglbin mlecule can carry 4 xygen mlecules Haemglbin is irn-based, taken in by the diet Haemglbin + xygen Oxyhaemglbin - Hb + 4O 2 Hb(O 2) 4 The presence f haemglbin in the bld increases xygen-carrying capacity by 100 times t abut 20mL (0.2 x 100 = 20mL) per 100mL f bld Haemglbin is therefr an adaptive advantage f mammals cmpare the structure f arteries, capillaries and veins in relatin t their functin STRUCTURE VS. FUNCTION TYPE QUESTION Bld is transprted within a clsed transprt system It is made up f three types f vessels 1. Arteries: carry bld away frm the heart 2. Capillaries: site f the exchange f materials between bld and tissue 3. Veins: take bld back int the heart Arteries Bld pumped ut f the heart is at a very high pressure, s the arterial structure must adapt t this They have thick walls made f elastic fibers and smth muscles Narrw but flexible lumen Expand with the cntractin f the heart Elastic allws walls t stretch s as nt t rupture Bld flw gin this way

13 When the diameter f the walls is increased, the pressure reduces a little and vice versa The lwering f the pressure f bld when it is high and the raising f it when it is lw smths ut the flw f bld A large artery will split int smaller arteriles that then branch further int many capillaries Arteriles have walls with a similar structure t arteries but have a greater prprtin f smth muscle and elastic (they dn t have t withstand high pressure) Capillaries The capillaries are where exchange between fluid and the bld can nly ccur 1 cell thick (6-8 um) T wrk efficiently capillaries, need t be small enugh t be clse with small grups f cells have thin walls t allw substances t mve in and ut f the bld T enable this there are tiny gaps between the cells making up the wall f a capillary Pressure changes acrss the capillary bed; this change is extraplated upn belw vv Tissue fluid think f the fllwing as a cyclic prcess; this is hw exchange f nutrients and xygen between the bld and bdy ccurs Tissue fluid is made up f plasma and disslved substances NOTE: A slute is the substance disslved (utside bld); a slvent is the substance ding the disslving (bld) At the arterile end f a capillary; where the arterile and start f capillaries meet 1. the hydrstatic pressure f the bld is high 2. The hydrstatic pressure is mre influential than the slute ptential f the utside (pressure t prevent inward flw f material) at the arterile end and therefr fluid/water leaves the capillary and carries with it int the cells glucse and xygen At the venule end f the capillary; at the end f the capillaries where they meet the vein 1. The hydrstatic pressure f the bld is lw and the slute ptential is higher (because fluid/water has been lst) 2. This will then cause fluid t be drawn back int the bld 3. At this stage, the fluid being drawn back is nw filled with waste/carbn dixide/urea Abut 90% f the fluid which leaks ut f the capillaries seeps back in; the remaining 10% becmes lymph

14 The lymphatic system allws tissue fluid t flw int its vessels via ne way valves These valves are large enugh t allw prteins (t big fr capillaries) int the lymph vessels If tissues fluid accumulates, blating r edema can ccur Bld cnsists f cells bathed in liquid plasma When this plasma leaks ut f the capillaries it is called tissue fluid Veins Capillaries jin t frm large venules which then frm veins Thinner muscle and elastic fibres than artery The bld pressure at this stage in circulatin is lw and needs t be encuraged t flw back t the heart Therefre n need fr elastic fibers r smth muscles in walls T prevent blackflw (caused by gravity) veins have valves Veins pass thrugh r clse t muscles The squeezing and cntracting f the muscles pushes bld in the veins twards the heart describe the main changes in the chemical cmpsitin f the bld as it mves arund the bdy and identify tissues in which these changes ccur Oxygen Oxygen in the bld changes as it mves arund the bld Oxygen (used in cellular respiratin) when leaving the cells decreases in the bld Bld that leaves the lungs is high in xygen and it decreases in the tissues (which has capillaries) where it is used fr cellular respiratin The desaturated xygen ends up in the veins Bld that leaves the capillaries is lw in xygen i.e. veins generally have lw xygen levels Carbn dixide Bld that leaves the bdy cells will be high in carbn dixide due t respiratin The bld that enters the lungs is therefre high in carbn dixide Gaseus exchange ccurs and the carbn dixide in the lungs decreases Waste nitrgenus material (urea) When waste leaves the liver and bdy cells, waste material is high in the bld until it reaches the kidneys where it is filtered ut Bld in the kidneys is therefr lw in waste after urinatin The capillaries becme high in waste cncentratin during the transfer frm liver t kidney Water Water enters in a bdy cell thrugh the digestive system Capillaries that leave the digestive system are high in water cncentratin Water is high in cncentratin in capillaries and therefr bld until the kidney filters ut any excess water Salts Salts enter the bldstream thrugh transfer with bdy cells and the digestive system

15 They travel t bdy cells t be used Hwever, excess is remved via kidneys Other prducts f digestin (vitamins, minerals, prteins, glucse, amin acids) Enter bld in the digestive system Bld that leaves the digestive system and liver is high in prducts f digestin such as glucse Remains high until it enters the bdy cells where it is used fr cellular respiratin utline the need fr xygen in living cells and explain why remval f carbn dixide frm cells is essential Oxygen is necessary fr cellular respiratin (refer t 2.2 fr detailed ntes) Glucse + xygen carbn dixide + water + ATP C 6H 12O 6 + O 2 CO 2 + H 2O + ATP Cells prduce carbn dixide as a result f respiratin Carbn dixide enters the bldstream and is carried in ne f three ways: 1. Abut 70% f CO 2 cmbines with water t frm hydrgen carbnate ins in the RBC (Carbnic acid hydrgen ins + hydrgen carbnate ins) CO 2 + H 2O H 2CO 3 H HCO % f CO 2 cmbines with haemglbin t frm carbaminhaemglbin 3. Arund 7% is disslved directly int the plasma Carbn dixide levels change the ph f the bld The ph f the bld is measured in the chemreceptrs in the hypthalamus It shuld remain Lw ph (a high acidity level) results in increased breathing rate ph in the bld and cells must be carefully maintained fr ptimal enzyme efficiency describe current theries abut prcesses respnsible fr the mvement f materials thrugh plants in xylem and phlem tissue Mvement f Water in Xylem Several prcess are invlved in the upward mvement f water in plants Capillarity: the rise f water in thin tubes by frces f adhesin and chesin Adhesin: frces f attractin between different particles f the plant and water Chesin: attractin between water particles Rt pressure: the upward mvement f water caused by the pressure frm water mving int the rt thrugh smsis

16 Transpiratin chesin: the lss f water mlecules frm the leaves (transpiratin) results in the upward mvement f mre water mlecules (chesin) Guttatin: the lss f water in the frm f a drplets frm penings n the leaves Mvement f Sugars in Phlem Translcatin: mvement f prducts f phtsynthesis in the phlem Bilgists studied the ways that radiactively marked sugars mve thrughut plants. Observatins included: Their mvement in the phlem is rapid; 1 metre per hur The directin f mvement can be reversed Mvement f materials can be in different directins in different parts f the same vascular bundle

17 Pressure flw thery/surce > path > sink ACTIVE: Sugars are pumped int the phlem cell due t active transprt. This results in higher sugar cncentratin inside the phlem cells. Site f sugar prductin in leaves High smtic pressure PASSIVE: Water mves int the phlem cells frm the xylem due t smsis as a result f the higher sugar cncentratin. This results in sugar being pushed dwn the phlem. ACTIVE: Sugars are pumped ut f the phlem cells lw in sugar by active transprt and int sinks Lw smtic pressure Mvement f sugar and water thrugh the phlem alng an smtic pressure gradient PASSIVE: Water mves ut f phlem cells back int xylem by smsis due t mre sugars in the surrunding cells. Site f use f sugars in fruit, flwers, rt and stem XYLEM Dead Rts shts (ne way) Transpiratin Passive Larger tubes Water and disslved substances Mves in ne directin Strengthened with lignin Transprt tissue N cytplasm PHLOEM Alive Shts all ther parts (any directin) Translcatin Active and passive Smaller tube Sugars and hrmnes Can mve up and dwn in bth directins Cmpanin cell with a nucleus Transprt tissues Cytplasm Sieve cell Sugars are pushed dwn the phlem tube via water mving int the cells by smsis which is passive transprt Sugars are unladed int the cells that need it via active transprt Water mves int rts by smsis (high cncentratin f ins in rts) GET A DIAGRAM OF A LONGITUDINAL XYLEM CELL

18 Lngitudinal versus transverse vascular bundle. Learn these! perfrm a first-hand investigatin t demnstrate the effect f disslved carbn dixide n the ph f water Aim: t demnstrate the effect f disslved carbn dixide n the ph f water Methd: 1. Place distilled water in cnical flask 2. Add universal indicatr t water and bserve it turn green, a ph f 7 3. Exhale thrugh straw int distilled water fr tw minutes 4. Add universal indictr t water again It turned frm a green 7 t a yellw HOMEWORK QUESTIONS MAY NOT BE PARTICULARLY RELEVANT 1. The ph f the distilled water may have been abve 7 (the usual ph fr drinking water) due t the dishwashing liquid used n the cnical flask in which the water was pured. Dishwashing liquid has a ph f 7-8 and may have raised the water s ph. 2. Universal indicatr utilizes clr as a symbl t help identify the ph, whilst the ph sensr can pin pint the numerical ph f the substance. The ph sensr can als recrd change in ph ver time, whilst the universal indicatr recrds the ph at the mment in which it mixes with the substance. 3. T prve that exhaled air cntains carbn dixide, the limewater test can be dne. This invlves: a. Add 50 ml f lime water t tw beakers b. Bubble rm air thrugh a pipette using a pipette pump fr ne minute int ne beaker c. Bubble exhaled air thrugh a pipette using yur muth fr ne minute int ne beaker d. Observe the results. (rm air shuldn t cause any change in the beaker, whilst exhaled air will cause the carbnic acid and limewater t cmbine and frm a white precipitate frmed by calcium carbnate). 1. Hmestasis is defined by the self regulating prcesses by which a bilgical rganism maintains stability and adjusts t the features (temperature, ph, etc.) f its ambient surrundings. The respiratry system helps t maintain an rganism s hmestatic state by inhaling xygen and exhaling carbn dixide, which if left t build up can pisn the bldstream. 2. Cartid bdies and artic bdies are chemreceptrs fund in the bld vessels in the neck that detect slight increase in acidity caused by CO 2 levels. Cnditins that may cause increased CO 2 levels include: a. Hypventilatin, shallw r lw breathing which lets carbn dixide build up and less t be exhaled (this can be caused by sleep apnea r drug verdse)

19 b. Airway blckages can be caused by asthma r lung disease which als causes hypventilatin c. Diminished gas exchange, CO 2 must be transferred t the lungs frm the bld via air sacs, capillaries. Diseases such as pulmnary edema (fluid in the lungs) restrict exchanges; smetimes there is s much CO 2 in the bld it is difficult t transfer d. Expsure t high levels f atmspheric carbn dixide r bad ventilatin The medulla blngata is the cntrl center fr breathing It has chemreceptrs which mnitr CO 2 levels When the chemreceptrs detect high CO 2 levels a message is sent t the intercstal muscles and ribs t increase breathing rate and depth Feedback the breathing rate is slwed Stimulus CO 2 levels rise Respnse CO 2 levels drp, ph rises and becmes less acidic Receptr chemreceptrs in medulla blngata detect increase Effectr intercstal muscles and ribs mve faster and deeper transmissin message is sent t intercstal muscles and ribs t increase breathing rate and depth perfrm a first-hand investigatin using the light micrscpe and prepared slides t gather infrmatin t estimate the size f red and white bld cells and draw scaled diagrams f each 1. Carry and set up the micrscpe. Ensure the light is switched n. 2. Place a minigrid n the stage f the micrscpe and fcus the micrscpe n lw pwer 3. Nte what size each grid is in mm and cunt the number f bxes acrss the diameter In ur investigatin, we fund that at x40 (4 x 10) the FOV (field f view) was 4.1mm; at x100 (10 x 10, which is an increase f 2.5) the FOV was 1.5mm When magnificatin increases, FOV decreases 4. Place bld slide n stage and cunt hw many bld cells acrss there are at LP and then HP

20 5. FOV divided by NUMBER OF CELLS = hw big thse lil red babies are analyse infrmatin frm secndary surces t identify current technlgies that allw measurement f xygen saturatin and carbn dixide cncentratins in bld and describe and explain the cnditins under which these technlgies are used Oxygen cncentratin is referred t as xygen saturatin Oxygen saturatin is the percentage f haemglbin saturated in xygen Oxygen saturatin and carbn dixide cncentratin in the bld are measured by current technlgy Bld gases are ften expressed in terms f the pressure the gas exerts and have the units mmhg Pulse Oximeter Nn invasive, prtable, simple and prvide cntinuus data Measures bld flw and pulse Measures the amunt f xygen in the bld by sensing the change in clr f circulating bld Bld is bright red when there is plentiful xygen which has attached t haemglbin (Oxyhaemglbin) Bld is dark purple when there is less xygen Lks like a clthes peg which fits n the finger Red infrared light is emitted frm the tp f the peg and the amunt f light which passes thrugh the skin is detected by an electrnic sensr n the bttm f the peg The value determined by a prcessr and is used t calculate the amunt f xygen in the arterial capillaries, which usually are % saturatin Used fr patients wh are underging surgery have abnrmal breathing r circulatin are in intensive care, emergency r wards in recvery have respiratry r cardiac issues have sleep apnea are athletes r muntain climbers in high altitudes pilts flying unpressurized aircraft Arterial Bld Gas Analysis Machine that measures bth xygen and CO 2 A small sample f bld is taken frm an artery, meaning it is an invasive technique The mvement f xygen thrugh a membrane frm the bld prduces an electrical current

21 Cnverted by the machine t a digital reading f the partial pressure/amunt f xygen The diffusin f carbn dixide thrugh a membrane changes the ph f the slutin inside the membrane Carbn dixide prduces carbnic acid and the acid dissciates hydrgen ins in plasma Used by the machine as a measure f CO 2 present Used when a patient is In treatment In surgery Have abnrmal breathing r circulatin Shivering (physilgical) Experiencing vascnstrictin Labur wards Intensive care wards mnitr the the success f ventilatin prcedures during which air is punched int the lungs analyse infrmatin frm secndary surces t identify the prducts extracted frm dnated bld and discuss the uses f these prducts A bld transfusin is the transfer f bld r any f its cmpnents t a recipient Bld transfusins are necessary in life threating situatins, surgeries r treatment f sever burns etc. The standard bld dnatin is 450mL The bld is tested fr the presence f antibdies, hepatitis and HIV. The type is then determined Dnated bld may be given as whle bld r brken int cmpnents using a centrifuge. Cmpnents include Plasma White bld cells and platelets Red bld cells Antibdies Cltting factrs Albumin Cmpnents f Dnated Bld Descriptin and Functin Type f Recipient Whle bld Bld which has been directly extracted frm the bdy and nne f its cmpnents have been extracted. Red bld cells 6-8 um in diameter Whle bld supplies cells, tissues and rgans with sugars, xygen and hrmnes; it als helps t flush waste prduced by cells ut f the bdy Erythrcytes, mst cmmn and are the primary way t deliver xygen t tissues, then Thse with live infectins, wh cannt make their wn bld Anemic peples wh have bld deficient in things such as irn r B-12 Surgery! Majr accidents r trauma Surgeries such as thse fr cancer lead t red bld cell lss

22 bring carbn dixide back t the lungs. Small, rund and bicncave. Membrane is cmprised f lipids and prteins, has n nucleus and cntains hemglbin (gives bld red clur) White bld cells (e.g. Leukcytes granulcytes) belng t the Between um in immune system diameter accunt fr 1% f the bld made in the bne marrw fight antigens cntain nucleus tw imprtant types are phagcytes (surrund and engulf pathgens) lymphcytes (specialize int B and T cells) between per ml f bld Platelets Clrless cells which 3um circle thrugh the bldstream n nucleus bind tgether when a bld vessel is damaged and bind t the site f the cut and cause the bld t clt, helping t stp bleeding Antibdies Prteins/immunglbins that are prduced by B cells when an antigen is present bind t antigens detected within the bdy via an antigenantibdy cmplex and wrk t kill r deactivate the antigen Cltting factrs (Factr VIII) Prtein which is created by the F8 gene and assists in bld cltting Anemia, dn't have enugh red bld cells t carry xygen t tissues Lw levels f hemglbin Oxygen deficient cirrhsis, emphysema Chemtherapy can damage bne marrw cells Rarely are WBC given, instead dctrs prescribe clnystimulating factrs t help the bdy make its wn Anybdy with a cmprmised immune system Recvery, WBC are lw and the bdy is fragile and susceptible t disease Thse with lw platelet cunt (thrmbcytpaenia) Chemtherapy Bne marrw transplantatin Majr surgery Liver disease Severe trauma Thse wh s bdy cannt prduce its wn antibdies, passive immunity Thse wh may be ill with a severe illness and need an instant bst in antibdies (snake bite, tetanus) Hemphilia A Vn Willebrand syndrme

23 circulates thrugh the bld bund with the vn Willebrand factr until an injury which damages tissue is detected interacts with factr IX t catalyze a chain f reactins which helps bld clt Albumin Glbular prteins, water-sluble fund in bld plasma main functin is t regulate the smtic pressure f bld can bind with water, catins, fatty acids, hrmnes etc. Plasma 90% water, straw clred, slightly salty, sticky slutin. makes up 55% f the bld It cntains ins and large plasma prteins. It has a ph f arund 7.4 Slutin by which all ther cmpnents are carried Transfusin f albumins has reprtedly n effect n the patient Shck Heart surgery Burns Hemdialysis Cirrhsis Cancer Childbirth Haemphilia Peple with significant fluid lss (BURNS), risk f dehydratin HIV analyse and present infrmatin frm secndary surces t reprt n prgress in the prductin f artificial bld and use available evidence t prpse reasns why such research is needed REASONS WHY SUCH RESEARCH IS NEEDED Artificial bld is a substance created t act as a substitute fr the red bld cells Artificial bld is created fr the sul purpse f transprting xygen arund the bdy

24 Therefr it represents emergency and temprary treatment It cannt defend against pathgens r clt bld Artificial bld is needed because: T deal with demands when bld supply is insufficient 1 in 30 Australians dnate bld while 1 in 3 will need bld at sme pint in life Dnated bld has a shelf life f 1 mnth. This is cstly and time cnsuming Dnated bld must be typed and matched t specific bld grups O can be dnated t any bld type; A, B, and AB cntain specific prteins that cause bld reactins if matched incrrectly Dnated bld must be screened fr diseases Individuals living in Britain in the 1980s can t dnate due t mad cw disease cncerns Ideal artificial bld has the fllwing characteristics Must be cmpatible with the bdy i.e. the bld can be received n matter the bld style Has been prcessed t remve all diseases/viruses/etc. Must be able t transprt xygen and cllective carbn dixide Its must be shelf stable Artificial bld can last 1 year TIMELINE DEVELOPMENT OF PRODUCTION OF ARTIFICAL BLOOD: PROGRESS IN PRODUCTION 1616 William Harvey described hw bld circulated thrughut the bdy practitiners tried t substitute bld fr beer, milk, urine, sheep bld and plant resin 1800s ther materials trialed included haemglbin and animal plasma 1840 Hunefeld fund bld cntained haemglbin 1854 patients were injected with milk as a substitute fr bld t treat Asiatic chlera; physicians believed milk helped regeneratin f white bld cells 1871 trialed animal bld and plasma as a substitute; hampered by technlgical prblems including haemglbin separatin 1883 Ringer s slutin was created; it was cmprised f sdium, ptassium and calcium salts scientists fund the heart culd be kept beating by applying the slutin reductin in bld pressure caused by lss f bld culd be remedied by Ringer s slutin maintaining pressure and pump up vlume Landsteiner discvered when bld frm different subjects was mixed the bld did nt always clt He suspended RBC in a saline slutin then mixed each individual s serum with a sample frm every cell suspensin; cltting separated Landsteiner determined that human beings culd be separated int bld grups accrding t the capacity f their RBC t clt in the presence f different serums - Bld transfusin was made much safer nwards Wrld War II human plasma was used t save sldiers frm hemrrhagic shck 1966 experiments with mice suggested a new type f bld substitute; perflurchemicals (PFC) This gave scientists the idea t use PFC as a bld thinner

25 1968 the idea was tested n rats; the animals bld was cmpletely remved and replaced with a PFC emulsin. The animals lived fr a few hurs and recvered fully after their bld was replaced 1989 Flusl DA became the first FDA apprved bld substitute 2001 Suth Africa became the first cuntry t apprve Hempure, a substance made frm cw haemglbin used as an alternative t bld transfusins 2005 PlyHeme a haemglbin substitute was used in Phase III trial fr severely injured bleeding trauma patients 2005 xycte was apprved fr clinical trials n traumatic brain injuries in Switzerland 2008 a study revealed the results f five different bld substitutins administered t patients Thse with substitutes had a threefld increase in the risk f heart attacks cmpared t the cntrl grup given human bld 2005 apprved in Mexic June 25 The UK annunced a trial f 20 peple that will begin in 2017 lking at bld and transplant recipients DESCRIPTIONS OF ARTIFICAL BLOOD There are three types f artificial bld which are all still in the research stage: 1. Haemglbin based xygen carriers (HBCO) 2. Perflurcarbns (PFC) 3. Grwing red bld cells frm stem cells Haemglbin-based Oxygen Carriers (HBOCs) Easily supplied, extracted frm the red bld cells f cws There is n need fr bld typing and crss matching Mlecules are s small they clg up the kidneys, causing kidney damage. Thus they need t be treated in a prcess which clumps them tgether t make it a bigger prtein HBOCs are currently the bld substitute that is clsest t apprval Brands include: Hempure PlyHeme Hemspan Limitatins include Cstly requires refrigeratin (being a prtein) nly wrks within the bdy fr abut a day Perflurcarbns (PFCs) Cntain flurine and carbn atms Can carry 5 times mre xygen than haemglbin (ww!) Insluble in bld, thus they must be cmbined with lipids t frm an emulsin Perfect size, nt t small yet small enugh t reach tissues and prvide xygen in situatins where RBC fail t d s (e.g. strke victims) Brands include: Oxygen Oxycyte Advantages ver dnated bld: Lng shelf life

26 Universal, regardless f bld type Sterile, zer chance f transmitting disease Ptentially mass prducible at little cst Limitatins include nly wrks within bdy fr 2 days Grwing RBC frm stem cells RBC have been successfully grwn frm stem cells frm bne marrw r umbilical crds Cells selected t prduce O-negative bld (the universal dnr) A new trial will begin in 2017 where 20 vlunteers will receive RBC grwn frm stem cells Limitatins include Nt feasible at present as very cmplicated prcedures Expensive Time cnsuming chse equipment r resurces t perfrm a first-hand investigatin t gather first-hand data t draw transverse and lngitudinal sectins f phlem and xylem tissue Materials: A fresh stick f celery A single sided razr A glass r cntainer with water Esin (water based red fd dye) Methd: 1. Place an end f freshly cut celery with its leaves (t ensure transpiratin can mve the esin up) still attached int a cntainer cntaining a strng slutin f esin 2. Leave it until the dye is bserved in the leaves 3. Take a piece f the celery stalk and use a hard-backed razr blade t cut acrss it; a transverse sectin 4. Observe the sectin under micrscpe 5. Cut ff a piece f celery lngitudinally abut 2 cm lng 6. Observe the sectin under micrscpe 3. Plants and animals regulate the cncentratin f gases, water and waste prducts f metablism in cells and in interstitial fluid explain why the cncentratin f water in cells shuld be maintained within a narrw range fr ptimal functin N life can exist withut water Water plays a number f essential rles:

27 Water is the universal slvent inrganic and rganic mlecules (sugar) can disslve in it water is a plar mlecule which separates ins int true substances can frm a hydratin layer arund prteins, frming a cllid - sme imprtant lubricants are cllids metablic reactins nly take place in slutins where water is the slvent water is a transprt medium Water is an imprtant reactant the digestin f fd is a hydrlysis reactin respiratin and phtsynthesis need water Water has a favrable relatinship with heat It can absrb/release heat withut changing temperature Water has high heat f vaprizatin (liquid t gas), accelerates heat lss, when we perspire water evaprates frm the skin Water has a cushining effect Slutins in bdy cells and tissues frm a cushin arund rgans - The cerebrspinal fluid cushins the brain Therefre, water cncentratin must be held cnstant explain why the remval f wastes is essential fr cntinued metablic activity When nutrients enter the bld and then the bdy cells, they are invlved in numerus bilgical reactins f the metablism Majrity f these reactins are catalyzed by enzymes Interactins f these reactins ensures that the bdy can functin efficiently Smetimes metablic prducts are frmed that are f n use e.g. wastes, r ingestin f useless cmpunds EXAMPLE // caffeine, alchl Carbn dixide as well These waste substances can affect sme enzymes disrupt metablism and hmestasis damage cellular cmpnents accumulate and take up space EXAMPLE // excess hydrgen ins reduce ph (making it mre acidic) and can in turn effect the activity f enzymes and the xygen saturatin f haemglbin EXAMPLE // brain is vulnerable t ammnia, urea, txins and drugs. Hence, the bld capillaries in the brain are less permeable than ther capillaries, knwn as the bld-brain barrier Because f the imprtance f eliminating waste, the bdy has the urinary system which specifically perfrms this functin identify the rle f the kidney in the excretry system f fish and mammals The respiratry system cnsists f the lungs and brnchial tubes and the thracic (chest) cavity Ensures that xygen can enter the bld and carbn dixide leave There are mechanisms t t maintain these gases EXAMPLE // saturatin f haemglbin respnds t xygen saturatin in surrunding tissues

28 The ther substance exchanged between bdy and air in lungs is water vapur The lungs are within the bdy cre, which remains at a cnstant temperature, preventing excessive water lss The respiratry system is a part f the excretry system Other parts f the excretry system are the skin, urinary system and digestive system The skin Water lss is a mechanism fr heat lss and is under the cntrl f the autnmic nervus system As well as water, ingested drugs, small amunts f salts, nitrgenus wastes such as urea, lactic acid and vitamin C may be present in perspiratin (sweat) Thus the skin is an excretry rgan The urinary system Cnsists f the kidneys, ureters, bladder and urethra The kidneys have tw main functins Excretin - The remval f wastes frm the rganism Osmregulatin - The regulatin f the cncentratin f water and salts in bdy cells and tissues s that hmestasis is maintained; partially under cntrl f hrmnes Fiber (the undigested cellulse frm plant fds), the breakdwn f haemglbin, water and ther wastes are excreted via faeces via the large intestine Functin f mammalian kidneys Regulate water and salt levels via smregulatin Excrete sme nitrgenus waste in the frm f urea Urea is less txic and can be stred in the bladder The liver cnverts ammnia/nitrgenus waste t urea Functin f fish kidneys Regulate water and salt levels via smregulatin Excrete all nitrgenus waste in the frm f ammnia Ammnia is highly txic and therefr must be remved frm the fish quickly This is why mst nitrgenus waste (ammnia) is excreted by fish via the gills Fresh water fish Salt water fish Terrestrial animals Urine cncentratin Very dilute Very cncentrated Cncentratin varies Explanatin Hyptnic (watery) envirnment results in water mving int the fish by smsis and salt mving ut by diffusin. Thus water needs t be remved and salt retained Hypertnic envirnment results in water mving ut f fish by smsis and salt mving in by diffusin. Thus water needs t be retained and salts remved Hrmnes (e.g. aldsterne) regulate the cncentratin f urine based n changes in the rganism s activities and envirnment explain why the prcesses f diffusin and smsis are inadequate in remving disslved nitrgenus wastes in sme rganisms

29 Diffusin and smsis are frms f passive transprt where substances are transferred withut the cell expending energy Osmsis is a specialized frm f diffusin that invlves the mvement f water acrss a semipermeable membrane in an attempt t equal ut cncentratins In active transprt specific carrier prteins bind t a substance t carry it acrss the membrane. This requires the use f energy. 3.6 as well: In the kidneys bth passive and active transprt ccurs... Passive transprt/smsis ccurs during filtratin, where the smsis f water back int the bld and the mvement f sme ins Active transprt ccurs in secretin f substances, the selective reabsrptin f salts, and the mvement f nutrients back int the bld Diffusin and smsis are inadequate since these prcesses aim t balance cncentratins f slutes such as nitrgenus wastes This wuld mean that urea wuld be equal in the nephrn tubules and in the bld This will leave txic prducts f urea within the bld ALL UREA MUST BE REMOVED FROM THE BLOOD, therefre smsis (which achieves equal cncentratin in the bld and nephrn) is inadequate They fail t make them equal Therefr, in the kidneys we need ACTIVE TRANSPORT distinguish between active and passive transprt and relate these t prcesses ccurring in the mammalian kidney REFER TO NEXT DOT POINT explain hw the prcesses f filtratin and reabsrptin in the mammalian nephrn regulate bdy fluid cmpsitin The kidneys are smregulatry (regulate the internal salt and water cncentratins f the bdy) rgans that excrete urea Deaminatin Prteins are brken dwn in the cell metablism t becme amin acids They are brken dwn in liver via deaminatin Remve nitrgen frm the amin acids t frm urea Urea is transprted t, via the bld, the kidneys t be excreted in the urine Kidneys Cmpact, bean shaped Prduce yellw urine cmpsed f nitrgenus waste Each kidney is made up f millins f small filtering units called nephrns It is within nephrns where the urine is prduced Steps t the frmatin f urine 1. Filtratin Nn-selective prcess Bld is brught t the kidneys via the renal artery, which divides t frm a netwrk f capillaries called the glmerulus The bld pressure is s high in the glmerulus that sme f the liquid frm the bld is frced thrugh the walls f the bld vessels int the Bwman s capsule where the tw meet This liquid is called the glmerular filtrate

30 - Bld plasma, glucse, amin acids, water, hrmnes, urea, vitamins and minerals - nt bld, immunglbins r prteins because they re t big - cntains sme f the substances yur bdy can reuse Passive transprt 2. Reabsrptin At this stage, the bld is a custard cnsistency Surrunding each nephrn tubule is a large capillary netwrk As the filtrate travels thrugh the tubule, reusable materials are reabsrbed Useful prducts are actively reabsrbed back int the bldstream; requires energy - Glucse, amin acids, salts, nutrients Water mves passively back int the bldstream Occurs in the prximal and distal tubules, and the lp f Henle 3. Secretin Osm-regulatry Regulatin f the bdy fluid cmpsitin This invlves the bdy selecting specific salts and water levels required by the bdy Sme imprtant/key things t remember abut the nephrn All prducts except bld and large prteins are pushed int the Bwman s capsule Water and glucse are the very first things t be reabsrbed in the cnvluted distal tubule The tp half f the nephrn is within the crtex; the bttm half is within the medulla Water is reabsrbed in the descending Lp f Henle; salt is reabsrbed in the ascending Lp f Henle Ptassium (K+) and hydrgen (H+) are added int the nephrn tubules during secretin if necessary

31 utline the rle f the hrmnes, aldsterne and ADH (anti-diuretic hrmne) in the regulatin f water and salt levels in bld The nephrn acts as an sm-regulatry unit cntrlling salt and water levels Tw hrmnes, anti-diuretic hrmne (ADH) and aldsterne regulate salt and water levels ADH als called vaspressin Reabsrptin f water is cntrlled by ADH The hypthalamus mnitrs cncentratin f the bld ADH is made here The pituitary gland cntrls the release f ADH t which the kidneys react ADH is stred and released here Increased levels f ADH increase the permeability f the distal tubules and cllecting ducts and water mves by smsis back int the bld This ccurs when there has been water lss frm the bdy (sweating) The bld, when passing thrugh the brain, is detected by the hypthalamus t be dry When bld levels return t nrmal, the level f ADH decreases and mre water passes ut with the urine Aldsterne Prduced by the adrenal glands (n tp f the kidneys) These glands cnsist f tw parts The crtex, which secretes sterid hrmnes - Aldsterne is ne f these hrmnes The medulla, which secretes adrenalin Its functin is t increase the amunt f salt reabsrbed frm kidney tubules and as a result helps t regulate bld pressure EXAMPLE // if sdium levels are lw in the bld, aldsterne is increased and less salt is excreted by the kidneys, mving salt and water back int the bld and increasing pressure The reabsrptin f sdium ins (Na+) and ptassium ins (K+) back int the bld takes place in the lp f Henle and distal tubules Regulatin f bld pressure is essential t efficient transprt f materials arund the bdy and in the functining f many rgans Increased aldsterne results in increase in salt cncentratins within the bld and vice versa Changed secretin rates f aldsterne, in respnse t changes in the inic cmpsitin f the bdy and/r in the bld pressure, act t maintain hmestatic cntrl f bld pressure and inic cmpsitin f bdily fluids Increased salt reuptake in the distal tubule als causes mre water t be retained due t maintenance f smtic balance define enantistasis as the maintenance f metablic and physilgical functins in respnse t variatins in the envirnment and discuss its imprtance t estuarine rganisms in maintaining apprpriate salt cncentratins Enantistasis is the maintenance f metablic and physilgical functins in respnse t variatin in the envirnment

32 Mangrve is ften used t describe bth An individual plant species A type f swampy frest where trees grw Organisms which inhabit estuaries and can tlerate a wide fluctuatin in water salinities are called euryhaline EXAMPLE // crabs burrw int the sand where salt levels are mre unifrm t escape the fluctuating salinity f estuaries There are tw main ways euryhaline rganisms are adapted t salt cnditins: 1. Osmcnfrmers; mst marine invertebrates, allw the smlarity f their interstitial fluid and bld t fllw that f the envirnment 2. Osmregulatrs; mst marine vertebrates, use active transprt t maintain a cnstant smlarity f bld and interstitial fluid regardless f change t envirnment The grund in estuaries is waterlgged, meaning that the rts f mangrves have difficulty btaining xygen fr respiratin and grwth. There are sme adaptatins t remedy this: Pneumatphres extend abve the lw water tide line and absrb xygen frm the air Leaves excrete salt nt the upper surface Salt is accumulated in lder leaves, bark, rts and stem; these tissues are discarded and salt leaves the plant Mre Examples f Adaptatins MUSSELS // survive lw tide via tightening their shells r passing air ver mist gills t breathe SALMON // when mving t fresh water, the hrmne crtisl is released which influences the directin f salt transprt in the kidneys and acrss the gills MORE DETAIL An estuary is the fragile regin where fresh water meets salt water EXAMPLE // at a tidal muth r castal inlet Organisms that live in estuaries must adapt t fluctuating cnditins EXAMPLE // when the tide cmes in, the water becmes salty, when the tide ges ut the salt cntent declines EXAMPLE // fluctuating expsure t air If care isn t taken, humans can negatively impact estuaries via urban develpment, cutting dwn mangrves, and harming sea grass beds which are breeding sites fr prawn, and feeding grunds fr fish and birds describe adaptatins f a range f terrestrial Australian plants that assist in minimising water lss

33 Australia is a dry cntinent, s many plants shw adaptatins t minimize water lss Xerphytes are plants adapted t arid regins where water availability is lw EXAMPLE // cactus Adaptatins include: Structure, size and shape f leaves Extent f rt system Length f reprductive cycle Presence f waxy cuticle Water strage rgans Sunken stmates EXAMPLE // Spinifex grass Fund in inland Australia Behaviural adaptatin: nly prduce and release seeds after exceptinal rainfall in rder t ensure a mist germinatin envirnment Structural adaptatin: rts g int grund 3 metres, each rt develps frm the same ndes as the shts and has its wn water supply Physilgical: spiky leaves cntain silica which makes them rigid and unbending in high wind EXAMPLE // Eucalyptus Structural (?) adaptatin: thick waxy cuticle n leaves which acts as a prtective barrier and reflects sunlight therefr reducing evapratin EXAMPLE // Queensland bttle tree Has the ability t stre cpius amunts f water in fibrus inner bark layers, can drp its leaves during arid cnditins t stre water in trunk and reduce water lss via leaves Stmates WHAT ARE THEY // micrscpic prus penings in the epidermis f leaves and yung stems, usually lcated n the underside f a leaf THEIR FUNCTION // stmates are pened via pressure exerted frm surrunding guard cells. Stmata mediate a plant s water lss (transpiratin) and carbn dixide diffuses frm the surrunding atmsphere int the leaf HOW THEY CONTROL WATER LOSS // stmata cntrls water lss via pening at night t lse little water and clsing during the day t reduce evapratin. Change in internal pressure f guard cells affects the degree f stmatal pening (when turgr pressure increases and guard cells fill with ptassium and water, the stmata will pen. And vice versa) perfrm a first-hand investigatin f the structure f a mammalian kidney by dissectin, use f a mdel r visual resurce and identify the regins invlved in the excretin f waste prducts

34 Kidney Dissectin Aim: t dissect a mammalian kidney and identify the main structures, relating them t their functin Materials and methd: 1. Observe prtective uter layer f skin, called capsule 2. Identify the three tubes which enter the kidney The ureter, which is the large tube in the centre The renal artery, which has a thick wall The renal vein, which has a thinner wall 3. T bserve the internal structure f the kidney, cut thrugh the kidney lengthwise, carefully cutting away frm yur fingers 4. Nw lk inside. Yu will ntice a funnel-shaped structure with a hle in the centre. This hle leads int the ureter. Taken an bject like a knitting needle and push it gently thrugh the pening. Discver where the ureter leaves the kidney. 5. Find the fllwing structure: The brwn uter layer, where waste substances are squeezed ut thrugh membranes f the glmeruli int the Bwman s capsules An inner pink layer f medulla. Here, water and sme salts are reabsrbed int the bld frm the tubules f the nephrns A hllw whitish regin. This is the pelvis f the kidney where large cllecting tubes empty urine int the funnel-shaped beginning f the ureter Diagram f kidney (must include renal crtex, renal medulla, renal pelvis, ureter, and fibrus capsule)

35 gather, prcess and analyse infrmatin frm secndary surces t cmpare the prcess f renal dialysis with the functin f the kidney [DIAGRAM OF KIDNEY DIALYSIS PROCESS] Renal dialysis When kidney failure ccurs the patient must rely n sme alternative way f remving wastes Kidney failure can mean when bld acidity, urea, r ptassium levels increase much abve nrmal In kidney dialysis bld flws thrugh a system f tubes cmpsed f partially permeable membranes Dialysis fluid (dialysate) has a cmpsitin similar t bld except the cncentratin f wastes is lw It flws in the ppsite directin t the bld n the utside f the dialysis tubes Cnsequentially, waste prducts diffuse frm the bld int the dialysis fluid There are tw different ways t treat kidney failure: 1. Hemdialysis invlves the use f a kidney dialysis machine where the bld is diverted int an external machine and filtered autmatically and returned t the bdy the bld is taken via tubing thrugh a special filter which cleans the bld the bld flws frm yur vascular access and is pumped thrugh lines befre and after the dialyzer n the dialysis machine befre the bld is returned t the bdy mst peple need 3 sessins a week, each 4 hurs the dialyzer is surrunded by a puch f dialysate which the urea mves int the dialysate has the same salt, glucse etc. levels s the patient desn t lse their salt r glucse etc.

36 2. Peritneal dialysis Uses the peritneum membrane, a thin membranus sheath lining in the abdminal cavity and rgan cavity In this type f dialysis the bld is cleaned inside the bdy A catheter is placed int yur abdmen The abdminal area/peritneal cavity is slwly filled with dialysate/peritneum Wastes diffuse frm the bdy fluids and pass thrugh the membrane that lines the peritneum int the saline slutin It is then drained ut by anther catheter This reduces the risk f bld cltting and infectin There are tw types f peritneal dialysis 1. Cntinuus ambulatry: a persn uses gravity t intrduce sterile dialysis t the abdmen and then discnnects and is free t mve 2. Autmated: a persn cnnects t the machine and the dialysis is perfrmed vernight Kidney functin Kidneys eliminate nitrgenus wastes frm the bdy while cntrlling water balance. They play a majr rle in stabilizing the internal envirnment, (ph and temperature f bld) The kidneys filter the bld, remve wastes (salt, hrmnes, vitamins) and create a urine; this is knwn as the excretry system Yu wuld be unable t survive withut yur kidneys fr lnger than three days Structural features The dent n ne side f the kidney is knwn as the hilum This is where the bld enters/leaves the kidney - The renal artery enters the kidney and branches int arteriles and then int capillaries - The capillaries clump tgether t frm glmerulus - Each glmerulus is surrunded by a duble cup knwn as the Bwman s Capsule A kidney is a flattened bean shape abut 11 cm lng, are lcated n each side f yur spine and are prtected by the ribcage The uter layer is knwn as the crtex is gritty and extends int the medulla layer The functinal parts f the kidney and the nephrns are fund in these regins The frmulatin f urine begins with the filtratin f the bld thrugh the nephrn at the bwman s capsule the fluid mves alng the nephrn tubule and glucse and amin acids are reabsrbed by the bld urea and salts cntinue thrugh the tubule KIDNEY FUNCTION RENAL DIALYSIS SIMILARITIES Remves wastes frm bld Remves wastes frm bld Uses filtratin in glmerulus Uses filtratin in dialysis machine

37 DIFFERENCES Natural prcess Artificial prcess Cntinuus remval f wastes Waste remval nly ccurs while attached t dialysis machine Rapid prcess Slw prcess Uses passive and active Uses filtratin nly transprt Glmerulus is the filter Dialysis tubing is the filter Wastes and sme metablites are remved Water and wastes remved and metablites stay in the bld Internal prcess External prcess Urinatin ccurs N urinatin Filtratin and reabsrptin in a nephrn Osmregulatin and excretin by nephrns in the kidneys are accmplished by the prductin and eliminated f Urine Urine is prduced by: Filtratin f waste and useful substances frm the bld at the glmerulus/bwman s capsule Reabsrptin f useful substances int the bld and the tubules and lp f Henle Filtratin: Substances mve frm the bld int the Bwman s capsule because f the high pressure f the bld thrugh the glmerulus Diffusin, because there is a lwer cncentratin f substances in the bld and a higher cncentratin in the tubule Reabsrptin: Substances mve frm the tubules back int the bld Once the cncentratin has been balanced, energy must be used t mve substances (glucse, amin acids) back int the bld Energy use results in active transprt, which allws the bdy (specifically the endcrine system) t mnitr what is reabsrbed - EXAMPLE // all glucse is reabsrbed but nly sme salt What gets filtered int the Bwman s and what gets made int urine? Material Bwman s capsule (filtrate) Renal pelvis (urine) Nitrgenus waste urea Y Y Glucse Y N Amin acids Y N Salt (ins) Y Variable amunts Water Y Variable amunts Large prteins N N Bld cells N N Where in the nephrn it ccurs What substances are invlved Why it s imprtant

38 Filtratin The glmerulus Water, slutes, plasma, nitrgenus waste, glucse, amin acids, salts Reabsrptin Secretin The prximal and distal cnvluted tubules, and lp f henle In bth the distal and prximal tubules, and the cllecting duct Water and slutes (glucse, amin acids), small prteins, peptides, phsphate, urea, ptassium, sdium Ptassium, hydrgen and aluminium ins, creatinine, urea, sme drugs, hrmnes Filters the fluids lking fr large particles which cannt be transferred int the renal cavitiy, detects substances which may still be useful resurceful/recycling, bathes substances in fluids which cleanse them Reabsrbs any substances which are fund nt t be useful t be carried t the renal cavity, picks up substances which have been cleaned Gets rid f unwanted substances, keeps the bdy s bld balance f substances (ptassium, urea, acidic substances) in check Active Transprt Passive Transprt Kidneys example Uses energy Desn t require energy/atp Substances mve int the Mves mlecules against the cncentratin gradient (lw t high) Mves mlecules with the cncentratin gradient (high t lw) Bwman s capsule because f the high pressure f the bld thrugh the glmerulus. This is Allw bdy t maintain hmestasis by mving substances in and ut f cells Allw bdy t maintain hmestasis by mving substances in and ut f cells diffusin which desn't require energy and is passive (filtratin). Hwever, when Mve material acrss a membrane Mve material acrss a membrane substances need t be mved back int the bld this requires energy which is active (reabsrptin). Active transprt allws the bdy t be selective in what it reabsrbs e.g. it reabsrbs all glucse but nly sme salt present infrmatin t utline the general use f hrmne replacement therapy in peple wh cannt secrete aldsterne Hrmne replacement therapy began in 1927 Invlves restring the imbalance f hrmnes at levels that are nrmal fr the bdy by administering hrmnes Can influence fluid retentin, raise bld pressure and remve danger f heart failure Mdern day HRT invlves administering a genetically engineered hrmne called fludrcrtisne/flurcrtisl Taken rally nce a day

39 Adrenal insufficiency an endcrine r hrmnal disrder that ccurs when the adrenal glands d nt prduce enugh f certain hrmnes Symptms include Chrnic r lng lasting fatigue Muscle weakness Lss f appetite Weight lss Abdminal pain Hyperpigmentatin r darkening f the skin Addisn s disease/primary adrenal insufficiency ccurs when the adrenal glands are damaged and cannt prduce enugh f the adrenal hrmne crtisl r aldsterne r the pituitary gland which cntrls the adrenal gland is damaged f every 1 millin peple are affected in develping cuntries Incrrect sdium levels as a result f aldsterne insufficiency can cause prblems such as cardiac failure Secndary adrenal insufficiency ccurs when the pituitary gland a pea sized gland at the base f the brain fails t prduce enugh adrencrtictrpic (ACTH) ACTH a hrmne that stimulates the adrenal glands t prduce crtisl eventually the adrenal glands can shrink due t lack f ACTH stimulatin mre cmmn than Addisn s disease Aldsterne affects the bdy s ability t regulate bld pressure sends signals t rgans (the kidney, cln) that can increase the amunt f sdium the bdy retrieves frm the nephrn back int the bldstream r the amunt f ptassium released in the urine causes the bldstream t reabsrb water with the sdium t increase bld vlume indirectly helps maintain the bld s ph and electrlyte levels All f these actins are integral t increasing and lwering bld vessels Treatment fr Addisn s disease Replacing and/r substituting the hrmnes that the adrenal glands aren t making Crtisl is replaced rally with hydrcrtisne tablets, taken twice a day Aldsterne is replaced rally with dses f fludrcrtisne acetate, taken nce a day Increasing aldsterne may als require the patient t increase their salt intake During an Addisnian crisis, lw bld pressure and glucse, and high levels f ptassium can be life threatening Therapy invlves intravenus injectins f hydrcrtisne, saline, and dextrse (sugar) and then dses f fludrcrtisne acetate

40 analyse infrmatin frm secndary surces t cmpare and explain the differences in urine cncentratin f terrestrial mammals, marine fish and freshwater fish Prteins and nucleic acids cntain nitrgen in additin t water and carbn dixide This is ammnia, which is highly txic Organisms either excrete waste in the frm f ammnia, r cnvert it t a less txic prduct such as urea and uric acid Organisms that excrete ammnia are called ammntelic rganisms Organisms that excrete urea are call uretelic e.g. humans! Terrestrial rganisms Have an issue with excretin since they are nt surrunded by a cnstant excretry medium Since the ammnia cannt be excreted quick enugh, it must be detxified Mst terrestrial animals cnvert ammnia int urea r uric acid Urea is synthesized in the liver and excreted in the kidneys Sluble in water There is a risk that excessive amunts f water will be excreted T prevent this, the mammalian kidney can excrete urine that is mre cncentrated than bdily fluids, ensuring little water lss A third grup f animals terrestrial cnserve water by excreting uric acid as their principal nitrgenus waste prduct They are called urictelic Nt very sluble in water EXAMPLE // birds, reptiles, insect Frms a paste Aquatic rganisms In freshwater envirnments, cell fluids are mre cncentrated (mre salt) than surrunding water Therefre, in fresh water, cells tend t gain mre water by smsis than they lse In marine envirnments, cell fluid is less cncentrated (less salt) than the surrunding water

41 Therefr, in salt water, cells tend t lse mre water by smsis than they gain Excrete ammnia Diffuses int the surrunding water in which it is highly sluble Osmregulatin and excretin in fish Bny fish excrete mainly ammnia Ammnia is slute and txic, but fish avid pisning via access t water which dilutes the ammnia Fish urinate cnstantly They excrete urea thrugh the gills Absrb salt Fish excrete ammnia by diffusin frm the bld acrss the gill membranes Sharks and rays have a skeletn made f cartilage instead f bne; they excrete urea Crcdiles, tadples and mst aquatic invertebrates excrete ammnia Tadples excrete ammnia, but when they becme adult frgs, excrete urea Salt water fish Have a lwer cncentratin f salts in their bdies than the surrunding water Cnstantly lse water t their surrundings via smsis, particularly thrugh gill membranes Bny fish drink water with their fd intake t replace this water lss Fish have special cells in the gills that can excrete excess salt back int the water by active transprt Excrete cncentrated urine with lw water cntent Bny fish Freshwater fish Water is cnstantly taken up thrugh the bdy cells frm the surrunding water where salt cncentratin is lwer than the fish s bdily fluids Absrb salt acrss the gills Fish have the added disadvantage f Fish that mve between salt and fresh water The native bass Lives in freshwater castal rivers f eastern Australia Returns t estuaries in winter t breed Tw native eel species Migrate between fresh and marine envirnments Species such as the bass and eel are capable f changing their respnses t fit their envirnments and smtic changes

42 NEPHRON DIAGRAM use available evidence t explain the relatinship between the cnservatin f water and the prductin and excretin f cncentrated nitrgenus wastes in a range f Australian insects and terrestrial mammals Terrestrial mammals Mammals excrete urea which des nt require much energy fr prductin, but uses up a lt f water Mammals living in arid cnditins shw many adaptatins t assist them t cnserve water In ht weather, humans urinate less t cnserve water and cntradict evapratin frm the skin and lung surfaces, and vice versa The urine becmes darker and cncentrated Different animals prduce/excrete different waste prducts The type f waste prduced is dependent n the animal s envirnment; mre specifically, the water availability in the envirnment Aquatic animals excrete ammnia (which is txic) directly int the water Ammnia - Very txic - Requires n energy t be made - Must be eliminated immediately - Needs large amunt f water t dilute it - EXAMPLE // freshwater fish and aquatic invertebrates Terrestrial animals cnvert ammnia t less txic frms/prducts Frms Urea - Requires mre energy than ammnia t be made - Can be stred fr shrt time - Excreted in cncentrated frm - EXAMPLE // mammals, adult amphibians and sme fish Uric acid - Least txic - Requires large amunt f energy t be made - Can be stred fr shrt time - Can be excreted in extremely cncentrated frm (semislid white paste) - EXAMPLE // birds, insects, mst invertebrates Therefr the cncentratin f urine prduced by terrestrial animals is dependent n their water availability EXAMPLE // desert dwelling mammals prduce a highly cncentrated urine.

43 EXAMPLE // earthwrms can excrete dilute urine cntaining bth ammnia and urea MAMMAL CASE STUDY Australian crest-tailed mulgara Small, native marsupial mammal Lives in sandy, ht and arid desert regins f central Australia Carnivrus Prey includes insects, scrpins and spiders The mulgara accunts fr evaprative lss f water vapr via the airways and water lss thrugh structural, physilgical and behaviral adaptins STRUCTURAL AND PHYSIOLOGICAL // mulgaras minimize water lss by prducing very cncentrated urine (nearly 4000 mosm/l) cmpared t humans (1200 mosm/l). Therefre, they excrete urea, lsing far less water This is achieved by the functin f tw structures in the nephrns f their kidneys 1. Glmerular filtratin is reduced - meaning that less fluid leaves the bld and enters the kidney tubules 2. Tubular reabsrptin is increased, meaning that mre fluid is reabsrbed frm the tubules in the lp f Henle MAMMAL CASE STUDY #2 Australian spinifex hpping muse Placental mammal Lives in sandy deserts in Australia Can survive withut drinking liquid water and can therefr endure drught thrugh physilgical adaptatins such as Its kidney tubules reabsrb almst all water frm the kidney filtrate It therefr prduces highly cncentrated and almst slid urine - Apprx mosm/l Water surces fr the hpping muse are Fd Mainly cnsume dry seeds - The amunt f water in these seeds depends n the humidity f the air in which the seed is fund. Humidity at night is greater, meaning

44 Insects the seeds have the mst water cntent at night, and thus the hpping muse adpts the behaviral adaptin f ncturnalism - Stre seeds in burrws which are insulated, deep and where mice huddle during day, creating high humidity, and thus seeds in burrws have a great water cntent Metablic water When carbs and fat are xidized, the prducts are CO 2 and water - This water is used by the muse Free standing water Include dew and rainwater, thugh this type f water is very rare in arid cnditins Water lss ccurs via The skin Faeces Exhaled air Urine Milk (females nly) insects release nitrgenus waste as uric acid int the bdy fluid it is then absrbed by the Malpighian tubules and passes int the hind gut the lw ph in the tubules causes the uric acid t precipitate ut as crystals in the rectum there is selective reabsrptin f water and ins insects d nt urinate! Uric acid passes ut with their fd wastes in an almst dry frm Insects are fund in terrestrial envirnments such as grasslands and deserts where water is scarce Mst insects btain their water frm plants Eating leaves EXAMPLE // grasshppers Sucking nectar EXAMPLE // butterfly Sucking sap EXAMPLE // aphid Sme insects can g withut fd r water fr days EXAMPLE // the Australian plague lcus can survive n its stres f fat. Waste eliminated during this time is dry

45 INSECT CASE STUDY Bgng mth All insects have an exskeletn r cuticle which is impervius t water One f the layers f which the cuticle is cmprised f is called the epicuticle Within the epicuticle there are three layers 1. Inner lipprtein layer 2. Wax layer - Essential fr water retentin - Hydrphbic mlecules face utwards and rejects water 3. Cement layer - Prduces the wax layer All insects prduce uric acid in a dry paste prcess and analyse infrmatin frm secndary surces and use available evidence t discuss prcesses used by different plants fr salt regulatin in saline envirnments Plants living in saline envirnments must be able t tlerate high levels f salt. On land, vascular plants transpire when the stmatas are pen. Water is drawn up frm the rts t their leaves if the water in the sil is salty, then salt is als drawn up Salt accumulates in the leaves and shw dead areas knwn as salt burn and may die early High cncentratin f salt in the sil water reduces the difference in cncentratin between the plant cells and sil water; less water enters the plant by smsis and the stmata may clse, r grwth reduces Halphytes grw and thrive with high levels f salt Salt exclusin Salt tlerant plants can stp salt entering tissues. Halphyte rts prevent 95% f salt in sil water frm entering EXAMPLE // the castal mangrve Avicenna marina prevents 98% entering