Bilgy Learning Outcmes This dcument tells yu exactly what yu are expected t learn in each tpic cvered by the syllabus T the right f each piece f infrmatin yu need t learn there are three bxes representing the clurs f a set f traffic lights Red first; amber in the middle then green If yu dn t knw the piece f infrmatin, i.e. if it nt in yur memry the yu tick the red bx If yu knw it but nt perfectly, r nly partly understand it, then tick the amber bx When yu knw it, remember it and understand it well tick the green bx The aim is t get a cntinuus green clumn dwn the right-hand side. The fllwing clur cding is used in this dcument Red n the left-hand side are the majr sectins f the syllabus Blue are the main subsectins Pink dentes a definitin yu need t knw precisely Green represents a practical activity yu need t knw Brwn dentes the infrmatin yu need t be able t shw in a diagram 1
Intrductin What is Bilgy? Define as the study f living things Areas f Study in Bilgy: micrbilgy, genetics, entmlgy, eclgy etc. Knw and be able t give example f each f the Characteristics f Living Things 1. Organisatin: e.g. Bld system heart, arteries, capillaries, veins 2. Nutritin: btaining fd - either auttrphic r hetertrphic 3. Excretin: remval f metablic waste 4. Respnse: reacting t changes in the envirnment 5. Reprductin: prducing new rganisms 6. Respiratin: prducing energy required t carry ut prcesses Metablism: Define as all the chemical reactins in a cell r rganism Cntinuity f Life: Define as all cells derived frm ther living cells Species: Define as grup f rganisms that can interbreed and prduce fertile ffspring Auttrphic: Define as make their wn fd Phtsynthesis: Define as cnversin f light energy int chemical energy using CO 2, H 2 O and chlrphyll Chemsynthesis: Define as prducing fd frm chemicals withut using light energy Hetertrphic: Define as btain fd frm ther rganisms Difference between slar energy (frm sun) and cellular energy (frm respiratin). Scientific Methd Prcess: Observatin, hypthesis, experiment, checking, mdificatin if required, replicatin, publicatin, peer review, thery, law Principles f Experimentatin: cmparing results f tw setups where there is nly ne difference, s that any difference in the result can be attributed t the difference in setup Data: Define as infrmatin cllected Hypthesis: Define as an educated guess Experiment: Define as a (practical) test f a hypthesis Cntrl: Define as fr cmparisn with nly ne variable Thery : Define as Hypthesis that has withstd testing Law : Define as Hypthesis that has withstd lng term testing Replicatin: Define as repeat f an experiment Publicatin f results in peer reviewed scientific jurnal Limitatins : inaccurate equipment, human errr, changing wrld, dishnesty etc Genes and DNA Chrmsme structure: Heredity : Define as passing n f genetically cntrlled characteristics frm parents t ffspring e.g. bld type Gene expressin: Define as when a gene is switched n and prduces its characteristic e.g. the insulin prducing gene nly wrks in cells f the Islets f Langerhans in the pancreas DNA wrapped arund prteins called histnes Cding structures called genes Nn-cding lengths called junk DNA Spread ut and carrying ut functins when genes are switched n during interphase Shrtens and thickens and becmes visible during cell divisin Gene: Define as a sectin f DNA (r chrmsme) that has the infrmatin fr a particular characteristic r trait 2
DNA Structure Nucletide structure f phsphate, sugar and base diagram shwing bend Duble helix - tw strands f dexyribse sugar, phsphate and base - twisted ladder Fur nitrgenus bases: Adenine(A)-Thymine(T), Guanine(G)-Cytsine(C) Purine [A & G] and Pyramidine [T & C] Cmplementary base pairs: A-T and G-C Hydrgen bnding hlds bases tgether Crick and Watsn discvered structure f DNA Cding (genes) and nn-cding (junk) structures RNA Cmplementary structure t DNA Uracil instead f thymine Cmparisn f DNA RNA - DNA and RNA Dexyribse Ribse Duble stranded Single stranded Thymine Uracil Lnger Shrter Messenger RNA (mrna) carries infrmatin t ribsme Replicatin f DNA The pening f the helix by enzyme actin Synthesis f cmplementary nucleic acid chains alngside the existing chains Frmatin f tw identical helices DNA Prfiling Define as Analyses DNA f an individual fr accurate identificatin by cmparisn 2 applicatins: frensics r family relatinships r medical Stages : Cells brken dwn t release DNA DNA strands cut int fragments using restrictin enzymes Separatin f fragments using electrphresis The pattern f fragment distributin is analysed Cmparisn with ther prfiles Genetic Screening Define as testing fr the presence r absence f a particular gene DNA Extractin Lcate DNA frm a plant tissue (experiment) Chp kiwi fruit t break dwn cell walls Add washing up liquid t break dwn cell membrane Add salt t prtect DNA Kiwi has wn prtease which is an enzyme that breaks dwn histne and frees the DNA Heat in a water bath fr ten minutes t denature enzyme Cl in an ice bath t stp prtease Blend fr 3 secnds t prevent DNA breaking dwn Filter int test tube t remve cell debris Pur ice-cld ethanl dwn side f test tube as DNA is insluble in it DNA precipitates at interface f ethanl as a white slime Prtein Synthesis DNA cntains the cde fr prtein Triplet is grup f 3 bases n DNA This cde is transcribed t mrna (messengerrna) The transcribed cde carried by mrna ges t a ribsme (site f prtein synthesis) rrna (ribsmalrna) hlds mrna in place The cde is translated (turned int crrespnding amin acid sequence) and the amin acids are assembled in the crrect sequence taken frm mrna sequence t synthesise the prtein Cdn is grup f 3 bases n mrma Start cdn tells ribsme t start adding amin acids (i.e. making the prtein) Add cdn tells ribsme t add anther amin acid crrespnding t the cdn Stp cdn tells the ribsme t stp making the prtein trna (transferrna) brings apprpriate amin acid t match the cdn Anticdn is a grup f 3 bases n trna which match with cdn n mrna The prtein flds int its functinal shape as it is frmed Lcatin f prtein synthesis is in ribsmes in cytplasm 3
Genetic Engineering Prcess Applicatins Define as Manipulatin and alteratin f genes invlving Islatin: remving the desired gene frm the dnr rganism cell by cutting it with a restrictin enzyme Cutting : cutting pen the plasmid DNA using same restrictin enzyme Insertin: placing the dnr DNA int the plasmid DNA Transfrmatin: plasmid taken in by bacterial cell Expressin: bacteria reprduces and gene causes prductin f wanted substance (ne f each) Animal: inserting human bld cltting factr int sheep which is expressed in milk Plant: inserting herbicide resistance gene int maize Micr-rganism: inserting human insulin gene int bacteria Cell Structure Examine animal cell Examine plant cell Cell Cmpnents Knw basic parts f light micrscpe including: light, stage, bjective lenses, eyepiece lens, carse fcus and fine fcus. Magnifying pwer = bjective x eyepiece Electrn micrscpe Uses electrns Much mre pwerful Needs a vacuum t wrk Prepare and examine ne animal cell Scrape inside f cheek with a swab and rub nt slide Add sme methylene blue stain t make structures easier t see Add cver-slip at a angle t prevent bubbles Place n stage and turn n light View at lw pwer and fcus with carse fcus knb View at medium (x100) and high pwer (x400) fcus using fine fcus Unstained cells difficult t see Prepare and examine ne plant cell Remve thin layer f skin frm between layers f nin and cut a small square Place n slide Add sme idine stain t make structures easier t see Add cver-slip at a angle t prevent bubbles Place n stage and turn n light View at lw pwer and fcus with carse fcus knb View at medium (x100) and high pwer (x400) fcus using fine fcus Unstained cells difficult t see and their functins as seen with light micrscpe: Cell wall: made f cellulse and is framewrk fr cell Cell membrane: cntrls what enters and leaves the cell selectively permeable Cytplasm: All f cell except nucleus, cell wall and large vacule, hlds rganelles Nucleus: cntrls cell activities Vacule: stres fd and waste materials Chlrplast: phtsynthesis As seen under electrn micrscpe Knw the functins f, and Identify the fllwing structures Cell membrane: cntrls what enters and leaves the cell, selectively permeable Mitchndrin: prduces energy in frm f ATP by aerbic respiratin Chlrplast: phtsynthesis Nuclelus: makes cmpnents f ribsmes Nuclear pres: allws mrna and rrna t leave nucleus Ribsme: assembles amin acids int prteins using cde n mrna DNA: stres genetic cde 4
Prkarytic cells: define as have n nuclear membrane, n cell rganelles (e.g. mitchndria) Eukarytic cells: define as have nuclear membrane and rganelles Similarities: bth have cell membrane, bth have cytplasm, bth have DNA Mvement thrugh Cell Membranes Lcatins Plasmalemma (cell membrane) surrunding the cells Nuclear membrane arund the nucleus, Membranes arund rganelles such as the mitchndria and chlrplasts and within the cells Selectively Permeable: define as allws certain substances thrugh Diffusin: define as mvement f a substance frm an area f high cncentratin t an area f lw cncentratin e.g. perfume in a still rm Osmsis: define as mvement f water, acrss a selectively permeable membrane, des nt require energy e.g. water entering rts frm sil Applicatin f high salt r sugar cncentratin in fd prductin and preservatin Salt in bacn: smsis draws water ut f bacteria r fungi killing them Sugar in jam: smsis draws water ut f bacteria r fungi killing them Cnduct any activity t demnstrate smsis: Visking Tubing tied at bth ends One with sugar slutin(experiment) ne with water (cntrl) Place bth in pure water and leave fr several hurs Result: sugar slutin has increased in vlume water has stayed the same Cnclusin: water has entered sugar slutin by smsis Turgr: Define as pressure n the cell wall caused by the cell membrane pushing against the cell wall due t it being full f water Explanatin f turgidity: plant cells are hypertnic t their surrundings s water enters frm utside making the cells firm r turgid Plasmlysis: the cell cntents and membrane pull away frm the cell wall when placed in a hypertnic slutin as water is drawn ut by smsis Crennatin: animal cells shrivel when placed in a hypertnic slutin as water is drawn ut by smsis Cell Diversity Tissues: Define as grup f similar cells carrying ut a particular functin Animal tissues: (2 examples) e.g. bne and bld Plant tissues: (2 examples) e.g. xylem and phlem Tissue Culture: Define as grwing cells utside the bdy (2) Applicatins: Grwing skin fr grafts Grwing human cells fr cancer research experiments Organs: Define as a grup f tissues carrying ut a cmmn functin Animal: (1 example) kidneys Plant: (1 example) leaf Organ System: Define as a grup f rgans carrying ut a particular functin Circulatry system: (2 examples) bld, heart, arteries, veins and capillaries Breathing system: (2 examples) trachea, lungs, diaphragm 5
Cell Cntinuity Chrmsme Haplid number Diplid number Mitsis Cell cycle Meisis Cmparisn f Mitsis with Meisis Cancer: Define as All cells derived by divisin f ther living cells Unit f heredity made up f genes, nn-cding (junk) DNA and prteins. (1n): number f chrmsmes in a cell with 1 set f chrmsmes (2n): number f chrmsmes in a cell with 2 sets f chrmsmes Define as: divisin f cell t frm tw identical cells with same chrmsme number Cell spends life alternating between interphase and mitsis - mst cells mainly in interphase Stages - be able t draw and recgnize simple diagrams f each stage Interphase: chrmatin diffuse, spends mst time in this stage Prphase: chrmsmes visible, nuclear membrane disappearing, centriles mving t ples, spindle fibres frming Metaphase: nuclear membrane gne, chrmsmes n equatrial plate, spindle fibres attach centriles t centrmeres Anaphase: spindle fibres cntracting, chrmatids being pulled apart Telphase: nuclear membranes refrming, fibres disappearing Cytkinesis: cytplasm dividing Primary functin f mitsis Unicellular rganisms - reprductin Multicellular rganisms grwth and repair Frm f cell divisin that halves the chrmsme number i.e. 2n 1n Mitsis Meisis 2 cells prduced 4 cells prduced Identical Nt identical Same chrmsme number Half the chrmsme number Define as uncntrlled cell divisin 2 causes frm: nuclear radiatin, UV radiatin, chemicals such a benzene Diversity f General utline f the diversity f living rganisms Organisms The Five Kingdm system f classificatin. Knw examples and main features f & Variatin f Mnera: bacteria, n nuclear membrane, n rganelles Species Prtctista: membrane bund nucleus, rganelles, sme unicellular (ameba) and sme multicellular e.g. seaweeds Fungi: Yeast and Mucr r Rhizpus, all multicellular, cell wall f murein Animals: Invertebrates: have n backbne e.g. anemnes, wrms, mlluscs, insects, etc. Vertebrates: have backbne e.g. mammals, reptiles, fish, birds, amphibians Plants: hrsetails, ferns, flwering plants, gymnsperms( pine trees) and angisperms (flwering plants) mncts ( 1 seed leaf) and dicts (2 seed leaves) Evlutin Species Evlutin Thery f Natural Selectin Define as grup f rganisms that can interbreed and prduce fertile ffspring Define as change in a species, ver time, due t variatin and natural selectin caused by changes in the envirnment (bservatins that led t deductin fllwed by deductins) Observatins: Over-breeding: mre ffspring prduced than will survive t reprductive age Ppulatins cnstant Deductin: Struggle fr Survival Observatins: Variatin within a ppulatin: differences between individuals f a species Deductin: Survival f Fittest best adapted t envirnment Cntributin f Darwin: published thery as abve first Cntributin f Wallace: prduced thery at the same time as Darwin 6
Evidence fr evlutin Fssils: changes seen ver time e.g. hrse number f tes reducing with time Hmlgus structures: Pentadactyl limb - Define as same structure mdified fr different functins e.g. human arm, bird wing, whale flipper Ontgeny recapitulates Phylgeny: embry passes thrugh stages f evlutin Variatin is due t: sexual reprductin, mutatins Mutatin Define as spntaneus inheritable change Tw agents respnsible fr increased mutatin rates: Nuclear radiatin Chemicals UV radiatin Micrbilgy Bacteria Fungi (Rhizpus) Distributin f bacteria and fungi is very widespread in nature Bacteria Prkarytic : : n nuclear membrane and n cell rganelles Fungi Eukarytic : nuclear membrane and cell rganelles i.e mre advanced than bacteria Basic structure diagram shwing duble membrane, nuclear material, cell wall, plasmid DNA, slime capsule, flagella Three main types: rds, spheres, spirals Reprductin: by binary fissin (nt mitsis as they dn t have a nucleus) Nutritin: Saprphytic (feed n dead rganisms) Parasitic (live in r n anther rganism causing it harm) Factrs affecting grwth: temperature, availability f fd and xygen Grwth curves be able t draw diagram f grwth curve f micr- rganisms shwing Lag phase adjusting t new envirnment Lg phase rapid multiplicatin s ppulatin increasing rapidly Statinary Phase ppulatin steady cmpetitin fr fd and space and build up f waste materials causes increased death rate = multiplicatin rate Decline phase ppulatin drpping due t build up f waste materials which causes increased death rate Survival as endspres with shrunken cytplasm and resistant cat Pathgenic: Define as disease causing Antibitics: Define as substances prduced by micr-rganisms that kill micr-rganisms Antibitics as cure fr bacterial and fungal diseases n effect n viruses Ecnmic imprtance f bacteria: disease, spilage, fd prcessing, 2 beneficial bacteria: Lactbacillus in yghurt, symbitic in gut prduce vitamins B & K 2 harmful bacteria: tuberculsis, syphilis Ptential abuse f antibitics in medicine Dn t wrk n viruses - s dn t prescribe fr viral diseases Finish curse r relapse will be f a mre resistant frm (strain) Avid residues in milk and meat Batch Prcess: bacteria and nutrients added, grw, prducts remved, equipment cleaned Cntinuus Prcess: bacteria have nutrients added ver perid f time and prducts remved ver perid f time Structure: diagram shwing rhizids (anchrage), hyphae (digestin), mycelium ( grup f hyphae), sprangiphre, sprangium (reprductin by spres) Life cycle diagrams shwing Asexual reprductin: sprangium prduces haplid spres, dispersal Sexual reprductin: different strains lie parallel, prgametangia, gametangia, fusin f nuclei, resistant diplid, zygspre, dispersal, suitable cnditins, germinates, meisis, haplid spres frmed in sprangium Nutritin: by extracellular digestin f rganic material by hyphae 7
(Yeast) (General) Viruses Prtctista (Ameba) Structure: diagram shwing nucleus, large vacule and cytplasm Lifecycle: gets energy frm anaerbic respiratin f glucse C 6 H 12 O 6 = 2C 2 H 5 OH + 2CO 2 enzyme zymase frm yeast catalyses reactin Reprductin: by budding (diagram) Prductin f Ethanl Glucse slutin + yeast Cntrl n yeast Anaerbic cnditins (sealed with fermentatin lck) Ht plate 25 0 C Reactin finished when CO 2 prductin ceases Test fr alchl: add range acidized dichrmate slutin, heat, turns green Edible and pisnus fungi Ecnmic imprtance f fungi as fd, prducer f antibitics, agent f decay (recycling) Tw beneficial fungi edible, prduce penicillin, flavur cheese Tw harmful fungi pisnus (Death Cap), decay (muld), athletes ft Investigate the grwth f leaf yeast using agar plates and cntrls Cllect cut ash leaf with scissrs and put in plastic bag, handle with frceps Stick t lid f petridish with vaseline, lwer surface facing agar Replace lid ver nutrient (cntains fd) agar (jelly) Invert after 1 day t prevent cndensatin drplets drwning yeast Incubate fr several days at rm temperature Cntrl: leaf washed with alchl Result: Pink clnies are yeast cntrl n pink clnies Dispsal: Sterilise with Miltn and place in bin Safety: sterilise bench with alchl, wear rubber glves Precautins when wrking with micr-rganisms Asepsis: preventin f cntaminatin keep sealed and minimum pening Sterile: n unwanted micr-rganisms Cntainment and Dispsal Keep in sealed cntainers t prevent cntaminatin Sak in Miltn t sterilise then dispse f in bin Identify the prblem f definitin dn t respire and n rganelles- s nt living Variety f shapes be able t draw rd, sphere and bacteriphage Diagram shwing basic structure DNA cat, DNA r RNA inside cat Viral Reprductin: Attachment,: nly attaches t its wn hst Insertin,: DNA r RNA injected int hst cell Reprductin: destrys hst DNA takes ver cell: Prtein cats and new DNA r RNA frmed Assembly: Prtein cat and DNA assembled in new virus particles Release: Cell membrane brken pen t release new virus particles which can then infect ther cells Ecnmic and Medical imprtance disease, lst wrk days, cst f treatment Tw harmful examples: influenza, cmmn cld One beneficial example: insertin f genes int bacteria Diagram f sub-cellular structures: nucleus, cytsl, cytgel, cntractile vacule, fd vacule, pseudpdia Life Cycle Reprductin: by binary fissin Feeding: pseudpdia engulf bacteria, fd vacule digests, waste material t surface, left behind Osmregulatin: interir mre cncentrated s water mves in by smsis, pumped int cntractile vacule by active transprt (needs energy), vacule mves t edge, bursts. Marine frms smaller difference in cncentratin s less water mves in 8
Sexual Reprductin Human Diagram: General Structure (simple diagram frnt r side view) label fllwing structures Testes: prduce sperm and teststerne Epididymis: stres sperm Sperm duct: carries sperm t urethra using peristalsis at ejaculatin Cwper s gland: secretins lubricate penis fr intercurse, neutralises urine Seminal vesicles: secretes seminal fluid, nurishes sperm, alkaline t neutralise acids f vagina Prstate Gland: secretins activate and nurish sperm Urethra: carries sperm and urine t utside Be able t mark psitin f sperm prductin, sperm strage n diagram Female System Diagram: General Structure (simple diagram frnt r side view) - label fllwing structures Functins Vagina: place where sperm depsited, acidic t discurage micrbial grwth Ovary: prductin f eggs, prductin f estrgen and prgesterne Fallpian tube: carries egg t uterus Uterus: hlds develping embry, frms placenta with embry Cervix: neck f wmb Endmetrium: inner lining f uterus Be able t mark psitins f vulatin, implantatin and sperm depsitin n diagram Meisis prduces haplid sperm and haplid eggs (details nt required) Secndary sexual characteristics Define as : Anatmical features that begin at puberty under influence f sex hrmnes Male examples facial hair, deeps vice, brad shulders, facial and axillary hair Female examples develpment f breasts, increased sub-cutaneus fat, widens hips Rle f hrmnes Oestrgen: inhibits FSH, prmtes LH, thickens uterine lining, prduces secndary sexual characteristics Prgesterne : inhibits FSH, inhibits LH, maintains uterine lining, Teststerne: prmtes sperm frmatin, prmtes secndary sexual characteristics The Menstrual Cycle Main Events Rle f hrmnes Menstrual Disrder Birth cntrl Days 1 5 shedding f endmetrium - perid Day 14 - vulatin Day 28 - cycle ends If fertilisatin takes place placenta takes cntrl f hrmne prductin and stps cycle Oestrgen: inhibits FSH, stimulates LH, thickens uterine lining Prgesterne: inhibits LH and FSH, maintains uterine lining FSH: stimulates prductin f graffian fllicle LH: stimulates vulatin and frmatin f crpus luteum Feedback: prductin f ne hrmne affects prductin f anther One example e.g. fibrids One cause e.g. hrmne imbalance One preventin - dn t be verweight One treatment - surgery Cpulatin: Define as act f depsiting sperm in vagina using penis Measure s ne male and ne female frm each f fllwing types Natural: rhythm Mechanical: male cndm, female cndm, cap Chemical: must say cntraceptive pill nt just the pill Surgical: cutting and tying fallpian tubes r cutting and tying sperm ducts Fertilisatin In-vitr fertilisatin Define as Fusin f male and female gamete nuclei Lcatin f fertilisatin in tp 1/3 f fallpian tube Define as fusin f gametes utside bdy 9
Infertility Develpment f Implantatin Mrula Blastcyst Amnin Placenta Placenta Functins Define as inability t cnceive 1 cause in male frm lw sperm cunt, lw sperm mbility, endcrine gland failure 1 cause in female frm fallpian tube blckage, endcrine gland failure 1 crrespnding crrective measure fr male infertility 1 crrespnding crrective measure fr female infertility embry Define as embedding f mrula in endmetrium Define as slid ball f cells Define as hllw ball f cells Define as bag f fluid surrunding baby that prtects it frm physical shck Define as tissue frmed frm mther s and embry s tissue Diffusin f xygen, nutrients and antibdies int embry frm thers bld Diffusin f CO 2 and urea ut f embry Birth Stage 1: Labur rhythmical cntractin f uterus and breaking f waters Stage 2: Delivery f baby nrmally head first Stage 3: Afterbirth - delivery f placenta Breastfeeding Suckling stimulates milk prductin Milk prductin Prlactin: causes prductin f milk suckling causes its prductin Oxytcin: causes expressin f milk suckling causes its prductin Benefits Crrect balance f nutrients and temperature Sterile Delivery f antibdies t baby (passive immunity) Psychlgical attachment f mther and baby Phtsynthesis Define as Cnversin f light energy int chemical energy using CO 2, H 2 O and chlrphyll Chlrplast Structure Simple diagram shwing duble membrane, grana, lamellae, strma, DNA, starch grains Rle Turns light energy int chemical energy (in frm f carbhydrates) This chemical energy is then used by all animals as their surce f energy Equatin Knw the balanced equatin 6CO 2 + 6H 2 O = C 6 H 12 O 6 + 6O 2 Prcess Knw surce f requirements fr phtsynthesis Light: sun r artificial surce CO 2 : atmsphere frm cmbustin (diffuse in thrugh stmata) and respiratin Water: frm sil thrugh rts - brught up by transpiratin stream Light energy trapped by chlrphyll Light Dependent (Light) Stage Occurs n thylakid membrane f grana Pathway 1 cyclic (same electrns [e - s] return t chlrphyll) High energy electrns prduced frm light energy e - s are passed t electrn acceptr Sme e-s g t electrn transprt system and their energy used t prduce ATP and they then return t chlrphyll Pathway 2 nn-cyclic (different electrns return t chlrphyll) Sme e-s g t NADP+ t frm NADP Phtlysis - Splits water t release electrns, prtns (H + ) and xygen These electrns used t prduce ATP then they are passed t chlrphyll Oxygen released t atmsphere (diffuses thrugh air spaces and stmata) r used by cell fr respiratin Prtns (H + ) enter prtn pl Prtns (H + ) jin t NADP - t frm NADPH which is passed t Light Independent (Dark) Stage 10
Leaf structure Human Interventin Light Independent (Dark) Stage Depends n prducts f Light Stage Occurs in strma f chlrplast H + and e - s transferred frm NADPH t CO 2 and carbhydrate [C x (H 2 O) y ] prduced ATP prduced Light Dependent Stage supplies energy fr making carbhydrate ADP and NADP + regenerated and return t Light Dependent Stage t be reused Diagram be able t draw a sectin shwing a few cells f the fllwing types in crrect psitin: cuticle, upper and lwer epidermis, palisade layer, spngy layer, guard cells, xylem and phlem Lcatin f chlrplasts in palisade layer, spngy mesphyll cells and guard cells Use f additinal artificial light, heat and CO 2 t prmte crp grwth in greenhuse Shw effect f light intensity n rate f phtsynthesis Knw apparatus diagram f experiment Knw hw t increase light intensity mve lamp clser ( away t lwer intensity) Knw factrs t keep cnstant and hw t keep cnstant. CO 2 disslve sdium bicarbnate in water ; Temperature use a thermstatically cntrlled water bath Cntrl fr experiment cnstant light intensity lamp at ne distance Knw rate is measured as bubbles per minute Knw t leave fr 5 minutes after mving lamp t give time t adjust t new cnditins Be able t draw a graph prduced by the abve experiment Be able t explain graph slpe = increased light intensity causes increased phtsynthesis: plateau = increased light intensity des nt cause increased phtsynthesis Flwering Plant Plant Rt Stem Basic structure: rts, stem, leaves, flwers, seeds, buds, ndes and interndes Basic structure: main rt, lateral rts, rt hairs, apical meristem and rt cap Functins Anchrage: hlds it in place against wind/water Fd strage: especially in tap rts e.g. carrt and parsnip as sugars and starch Vegetative reprductin: e.g. dahlia r rchid Absrptin: f water and minerals frm sil thrugh rt hairs Basic structure: Diagram f transverse sectin (TS) shwing psitins f Vascular tissue xylem and phlem as transprt tissues Grund tissue crtex as packing tissue Dermal - epidermis and rt hairs (enddermis shuld als be knwn: nt derma tissue) Diagram f lngitudinal sectin ((LS) shwing psitins f rt cap, apical meristem (zne f multiplicatin), znes f elngatin, differentiatin and maturatin Rt cap prtects apical meristem as rt pushes thrugh earth Basic structure: Diagram f in transverse sectin shwing Dermal tissue: epidermis Grund tissue: crtex and pith Vascular tissue: xylem and phlem Meristematic tissue: cambium Functins Hlds leaves and flwers in place Stres fd e.g. ptat is stem tuber stem because it has buds (eyes) Cnduit f vascular tissue Has lenticels i.e. breathing pres Buds: miniature stems which can frm branches Ndes: pints f attachment f leaf and lcatin f buds Interndes: space between leaf attachments 11
Xylem Lcated n inner side f cambium in vascular bundles in stems Functins Transprt f water and disslved minerals up t leaves frm rts Supprt especially when lignified Tracheids: be able t recgnise and draw simple structure Pinted ends Lignified (thickened with lignin therefre dead) fr supprt and strength Cntain pits t allw lateral (sideways) mvement f water Vessels: be able t recgnise and draw simple structure Open ended tubes Narrw fr efficient vertical transprt f water Lignified (thickened with lignin therefre dead) fr supprt and strength Phlem Lcated n utside f cambium in vascular bundles Functins Transprt f disslved sugars up and dwn stem Transprt f plant hrmnes Structure: be able t recgnise and draw labelled diagram f simple structure TS and LS Sieve tubes have n nucleus and have sieve plates at end Cmpanin cells have nucleus and cntrl adjacent sieve tube Cambium Meristematic regin acrss middle f vascular bundles Leaf Site f phtsynthesis Sme plants stre fd in leaves e.g. nins Basic structure: petile and lamina (blade); veins are vascular bundles Large surface area t catch light Thin t allw efficient diffusin f gases Many chlrplasts fr phtsynthesis Diagram shwing a few cells f the fllwing types in crrect psitin: cuticle, upper and lwer epidermis, palisade layer, spngy layer and guard cells Excretry rgans f plants Excretry prducts stred in vacule and eventually kill leaf. These are remved frm the plant when the leaf falls ff Meristem Define as an area specialised tissue where there is rapid cell divisin(by mitsis) Primary (Apical): at the tips f shts and rts, cause increase in length Secndary: cause increase in girth Vascular: In cambium between xylem and phlem Crk: under bark prduces prtective layer f crk Knw the lcatin f meristems in rt and shts Chesin tensin Adhesin: frce f attractin between water mlecules and lignin in xylem walls mdel Adhesin causes capillary actin and pulls water abut 10 cm up xylem Transpiratin: evapratin f water frm xylem thrugh stmata Chesin: frce f attractin between water mlecules due t plarity f mlecules Tensin: water mlecule leaving xylem pulls next mlecule up which pulls next ne in sequence dwn vessel setting up a tensin within the xylem Tensin is main frce respnsible fr pulling water up stem transpiratin stream Dixn & Jly wrking in TCD develped this mdel Rt pressure caused by smsis pushes water abut 10 cm up stem Mncts Have ne seed leaf Strap shaped leaves and parallel veins Mst are herbaceus (nn-wdy) e.g. grasses, cereals and lilies bamb is wdy Vascular bundles scattered randmly thrughut stem Flral parts in threes r multiples Dicts Have tw seed leaves Brad leaves and netted veins Abut equal numbers f herbaceus (nn-wdy) and wdy species Vascular bundles arranged in a ring arund the stem Flral parts in furs r fives r multiples 12
Slide Preparatin Cut internde sectin f nn-wdy plant Hld firmly Using backed blade cut away frm yurself Cut as thin a slice as pssible Place slices in water Using a paintbrush transfer t slide Add idine stain t make easier t see Add cver-slip at an angle t prevent air bubbles being trapped Replace stain with water Examine under micrscpe Place n micrscpe stage and clip Switch n light Fcus using lw pwer (x40) using carse fcus knb Then using medium (x100) and then high (x400) fcus using fine fcus knb Nn-stained slide structures are mre difficult t see Nutritin Auttrphic: Define as make their wn fd (by phtsynthesis) Uptake / transprt Water Absrbed thrugh rt hairs by smsis Passes thrugh crtex frm cell t cell by smsis Passes thrugh enddermis by smsis Enters xylem by smsis Causes water level t rise abut 10 cm - called rt pressure Narrw xylem vessels cause capillary actin which als causes a small rise Transpiratin pull is the main frce causing water mvement up the plant Minerals: absrbed thrugh rt hairs, must be in slutin By diffusin if mre cncentrated in sil than in the plant n energy required By active transprt if less cncentrated in sil than in plant energy required Carried up plant in slutin in transpiratin stream Carbn dixide Sme frm cellular respiratin within plant Mst diffuses int leaf thrugh stmata frm atmsphere CO 2 levels are ne f the cntrlling factrs in stmatal pening Phtsynthetic prducts Oxygen Sme used in cellular respiratin Mst diffuses ut f leaf thrugh stmata t atmsphere Carbhydrates Can be used in cellular respiratin Or transprted arund the plant by phlem sieve tubes and stred 13
Eclgy Bisphere Ecsystem Habitat Niche Bitic factrs Abitic factrs Climatic Factrs Edaphic factrs Energy flw Ppulatin Dynamics Define as study f inter-relatinships f plants, animal and their envirnment Define as area arund the earth where life exists Define as habitat plus all the plants and animals that live there Define as place where a species lives Define as rle f species in the habitat Define as Living factrs Cmpetitin: Define as individuals striving fr a resurce that is in limited supply Predatin: Define as catching killing and eating anther animal Parasitism: Define as a clse relatinship between tw species where ne (the hst) is harmed e.g. bird fleas suck bld and act as vectr fr diseases Symbisis : Define as a clse relatinship between tw species where ne benefits e.g. bacteria in gut get fd and shelter we get vitamins B and K Mutualism: Define as a clse relatinship between tw species where bth benefit e.g. lichen: algae gets shelter and fungus gets fd Define as Nn-living factrs Temperature: measure using thermmeter Light : measure using light meter ph: measure using ph meter Wind speed measure using an anemmeter Define as relating t weather Temperature: measure using thermmeter Light : measure using light meter Wind speed measure using an anemmeter Define as relating t sil ph Water cntent The sun as primary surce f energy fr Earth Feeding as a pathway fr energy flw thrugh ecsystems Prducer: plant that cnverts light energy int chemical energy (fd) Primary cnsumer (Herbivre) eats plants Secndary cnsumer (Carnivre eats animals) eats primary cnsumer Tertiary cnsumer (Tp carnivre) eats secndary cnsumers Grazing fd chain: Fd chain starting with living plant shwing what feeds n what r flw f energy. Arrw directin imprtant as it shws directin f energy flw e.g. grass snail thrush sparrw hawk Detritus fd chain: Fd chain starting with dead plants e.g. leaf litter wd luse thrush sparrw hawk Fd web: Define as intercnnected fd chains e.g. grass snail thrush sparrw hawk blackbird Trphic level: Define as psitin in fd chain Pyramid f numbers: shws numbers f individuals at each trphic level Be able t draw pyramid Limitatins f use: gives n infrmatin f relative size f individuals Inverted pyramid f numbers: Be able t draw pyramid Prducer number smaller than primary cnsumer number; tells that prducer in large size Pyramid f bimass: shws dry weight f all rganism at each trphic level Variables in predatr and prey relatinships Availability f fd large ppulatins f herbivres reduce available fd s ppulatin declines This results in predatr numbers drpping Disease spreads mre rapidly in large ppulatins Be able t draw predatr prey graph with predatr numbers lwer than and changing after herbivre 14
Human ppulatin Human impact Nw in expnential (very rapid increase) phase Factrs affecting: war, famine, cntraceptin, disease all decrease ppulatin Pllutin: Define as any harmful additin t the envirnment Raw sewage spreads disease and destrys envirnment e.g. kills fish in waterways Cntrl f pllutin by legislatin and sanitary dispsal f sewage Cnservatin: Define as maintaining existing ppulatin Fishing cnservatin measures: minimum mesh size f nets, limit harvesting time i.e. set a seasn Waste management: Prblems assciated with waste dispsal: smell, vermin, leaching f pisns int envirnment Imprtance f waste minimizatin: as reducing the impact n the envirnment, Rle f micr-rganisms: breaking dwn waste in sewage treatment, breaking dwn il slicks Pllutin cntrl Effects f pllutant: Sewage causes eutrphicatin Cntrlled by prper management dn t discharge untreated int streams Eutrphicatin Nutrient recycling Ecsystem Study Define as excess plant grwth caused by excess nutrients Plants die and rt due t bacterial actin Oxygen used up s aerbic rganisms die Txic prducts f anaerbic respiratin build up an kill rganisms Define as returning elements t the envirnment s that they can be reused Be able t draw the carbn cycle Be able t draw the nitrgen cycle (names f bacteria nt required) Named ecsystem: Open grassland Identify five flra: grass, thistle, nettle, hawthrn, dandelin Flra: Define as plants Identify five fauna: use f a simple key t identify rganisms snail, earthwrm, thrush, sparrw hawk, fx Fauna: Define as animals Qualitative study: define as stating the different species present Quantitative study: define as estimating the numbers f individuals f a species present Identify a number f habitats frm the selected ecsystem: hawthrn bush, sil, grass Identify and use varius apparatus required fr cllectin methds in an eclgical study Pter Sweep net Mammal trap Pitfall trap Quantitative study f plants (daisies in field) Quadrat: square f knwn dimensin e.g. 50 cm sides = 0.25m 2 Measure area f study: length x width Randm sampling: thrw pen ver shulder and place quadrat where it lands Cunt individuals in each quadrat Calculate average number per quadrat: ttal N f individuals / N f quadrats taken Calculate number f quadrats that wuld fit in area: study area/quadrat area Calculate ppulatin: quadrats that wuld fit in area x average number per quadrat Surce f errr: quadrat distributin nt truly randm 15
Adaptatins Analysis Quantitative study f animals ( grund beetles in field) Set 20 pitfall traps and leave vernight Cunt individuals caught Mark discretely s predatrs wn t be attracted Release int same area where caught and leave fr a time t disperse Reset traps Cunt marked and unmarked individuals caught Calculate ppulatin: Ppulatin = N caught 1 st day x Ttal caught 2 nd day / N f marked caught 2 nd day Surce f errr: may have immigratin r emigratin Percentage Frequency: Define as percentage f quadrats in which species is present Percentage cver: Define as percentage f quadrat cvered by species Shw results using tables, diagrams, graphs, histgrams Define as features that help an rganism t survive in its envirnment Cluratin: Cryptic (camuflage) deer blend int wdland Apasmatic (bright) yellw and black f wasps warn predatrs f danger Thrns: discurage grazers Txins: discurage grazers Eyes n side f head allw grazing animals (rabbits) t see predatrs appraching Behaviural: rbins sing and display t prevent injury t each ther and winner assured f enugh fd t raise family Be able t identify lcal eclgical issues related t ecsystem Respiratin Aerbic Respiratin requiring xygen and prducing large amunts f energy (38ATP per glucse) Equatin C 6 H 12 O 6 + 6O 2 = 6CO 2 + 6H 2 0 Glucse + xygen = carbn dixide + water Prcess Stage 1 Called glyclysis Des nt require xygen Occurs in cytplasm Releases a small amunt f energy (2ATP) 6 carbn glucse prduces tw 3 carbn pyruvic acids If xygen present pyruvic acids mve int mitchndria Stage 2 Requires xygen Occurs in mitchndria Releases a large amunt f energy (36ATP) Pyruvic acid becmes acetyl grup by lsing ne C as CO 2 in lumen Jins with Cenzyme A t frm acetyl c-enzyme A Acetyl c-enzyme A enters Kreb s Cycle Jins with 4C cmpund t becme 6C and acetyl grup freed t be reused 6C cmpund lses 2 carbns as CO 2 s t frm 4 Carbn cmpund again then 4C reused H s g t electrn transprt system n Cristae where mre ATP and water are frmed If n xygen present In plants ethanl and CO 2 are prduced In animals lactic acid is prduced this can cause cramps if it builds up This is called fermentatin Small amunts f ATP frmed in bth cases See als prductin f alchl under yeast in micrbilgy sectin Anablic Reactins Define as reactin synthesising mre cmplex mlecule Requires energy (ATP ADP + P) Phtsynthesis and prtein synthesis as examples 16
Catablic reactins ATP Define as breaking dwn mre cmplex mlecule int simpler nes Prduces energy (ADP + P ATP) Respiratin as example Adensine triphsphate Stres energy Transprts energy Circulatry system Functins Vessels Transprt: carries xygen, CO 2 and fd arund bdy Temperature regulatin: carries heat arund bdy and when ht clse t skin t allw it t escape Immunity: prtectin against pathgens Cmmunicatin: distributin f hrmnes Clsed system in humans: cntained in vessels Arteries: T.S. Diagram Muscle, elastic fibre and lumen Carry bld away frm heart, Oxygenated except fr pulmnary artery which is dexygenated Thick muscular walls t withstand high pressure Small lumen Arteriles: small arteries muscles can cnstrict and reduce bld flw e.g. t skin t prevent heat lss Capillaries: T.S. Diagram ne cell thick wall and lumen Walls ne cell thick Gaps t allw tissue fluid t escape Clse t every cell in bdy Venules: small veins which jin tgether t frm veins Veins: T.S. Diagram Muscle, elastic fibre and lumen and LS shwing valves Carry bld t heart Dexygenated except fr pulmnary vein which is xygenated narrw Thin walls Large lumen Lw pressure Valves t prevent back flw Tw-circuit circulatry system Pulmnary: t lungs, driven by right side f heart Systemic : t rest f bdy driven by left side f heart Tw circuits separated by septum Structure: Diagram shwing the main pathways f bld circulatin: Pulmnary artery, pulmnary vein, arta, crnary artery, cartid artery, jugular vein, sub-clavian artery, hepatic artery, mesenteric artery, renal artery and the crrespnding veins Diagram a fully labelled diagram f the heart and shw directin f flw Hepatic prtal system N mesenteric vein. Bld frm intestine is rich in glucse and amin acids and enters liver thrugh the hepatic prtal vein. Diagram f liver with hepatic artery and vein and hepatic prtal vein and shw directin f bld flw in each bld vessel Heart is supplied thrugh the crnary arteries Heart muscle tissue specialized strng, branched and never tires 17
Heartbeat Sund made by valves clsing Rate: Abut 70 beats per minute Cntrl: CO 2 levels in bld mnitred by medulla blngata Pacemaker: Pacemaker initiates cntractin and Purkinje tissue distributes it Knw lcatin f pacemaker ndes (SA and AV) n diagram Pulse: define as pressure wave caused by heart beat Bld pressure: define as frce f bld n artery wall measured at upper arm Cardiac cycle Systle: perid f cntractin, heart empties Diastle: perid f relaxatin, heart fills Dissect sheep s heart Place n bard runded side up Identify left and right sides (wners) left side bigger Identify crnary arteries Make cut frm centre f atrium t centre f ventricle nt n septum Identify tricuspid (right) and bicuspid (left) valves Lcate semi-lunar valves by cutting dwn pulmnary artery and arta Flag label structures Cut acrss ventricles and nt that left ventricle has thicker wall because it has t pump bld further Investigate the effect f exercise n the pulse rate f a human Measure resting pulse rate at wrist using secnd finger in beats per minute (15 secs x 4) Gentle exercise (walking) fr tw minutes Recrd new pulse rate Nte time taken t return t nrmal Strenuus exercise (running) fr tw minutes Recrd new pulse rate Nte time taken t return t nrmal Result: heart rate increases with level f exercise Fit persns heart beat is slwer and returns t resting rate faster Bld Bld gruping Effects f Smking: causes cancer, athersclersis, emphysema, increased risk f cltting Diet: excess fats cause high bld pressure, blckage f arteries leading t heart disease Exercise: imprves efficiency and reduces risk f heart disease Cmpsitin Red bld cells: bicncave discs, n nucleus r mitchndria, cntain red pigment haemglbin, prduced by bne marrw Carry xygen arund bdy as xyhaemglbin White bld cells Lymphcytes: Mncytes: Platelets: cellular fragments that play a majr rle in bld cltting Plasma: liquid part f bld Carries glucse, amin acids, plasma prteins e.g. fibringen, disslved minerals and CO 2 arund bdy Based n antigens n surface f bld cells A has antigen A can accept bld frm A r O B has antigen B can accept bld frm B r O AB has antigens A and B can accept bld frm all grups O has n antigens and can nly accept frm O but can be dnated t any grup Rhesus factr: Rh+ has rhesus antigen Rh- des nt have antigen Rh+ baby in Rh- mther can cause mther t prduce antibdies that attack the baby Anti-D given t mther t stp attack 18
Lymphatic system Structure Capillaries: cllect excess tissue fluid, fluid mved by being squeezed when muscle cntract, valves prevent backflw Functins Any 3 Lymph ndes: swellings which filter lymph, prduce lymphcytes and detect antigens Lymph vessels: Capillaries drain int vessels and lymph mves t thracic duct frm where it enters bld at sub-clavian vein Circulatry: Cllects and returns excess tissue fluid, Cllects and delivers absrbed lipids: lipids enter lacteal as glycerl and fatty acids which recmbine int lipid Defence: Ndes filter pathgens, cell debris and cancer cells Prduces and exprts lymphcytes Detects antigens and prduces specific antibdies Defence System General Specific Rle f lymphcytes Skin: bacteria prf, Symbitic bacteria and fungi stp establishment f pathgenic clnies Dead cells fall ff remving pathgens Sweat and sebum are anti-bacterial Mucus membrane lining f the Breathing tract: trap micr-rganisms and remve them frm bdy via stmach and spitting Reprductive and: acidic secretins kill bacteria Digestive tracts: Stmach cntains HCl which kills bacteria ingested with fd Phagcytic White Bld Cells: wander in all parts f the bdy t seek ut, engulf and destry pathgens and damaged cells. Especially abundant in lymph ndes Immune System Antigen: a nn-self chemical that causes the prductin f an antibdy (i.e. an immune respnse) Antibdy: substance prduced by a bdy in respnse t a freign prtein (i.e. an antigen) Passive immunity: antibdies received frm anther surce e.g. embry frm mther in milk and Anti-tetanus received in an injectin Induced (Active) immunity: Define as prtectin gained by detectin f antigens and the prductin f specific antibdies that neutralise the antigen Natural: bdy respnds t invading pathgen Artificial: bdy respnds t (i) dead, (ii) attenuated (weakened) r (iii) a fragment f a pathgen. This is called vaccinatin B lymphcytes prduce specific antibdies T lymphcytes act against virus infected and cancer cells Helper T cells stimulate multiplicatin f ther T and B cells Killer T cells kill pathgenic, infected and cancer cells by injecting lethal chemicals Suppressr T cells restrain the activity f T ad B cells when pathgen has been destryed Memry T cells remain lng after infectin and remember it t give immediate respnse if infectin is encuntered again. Vaccinatin: is the act f administering a substance that prduces artificial immunity Immunisatin: prtecting a ppulatin/patient against a specific pathgen by vaccinatin r injectin f particular antibdies e.g. MMR against measles, mumps and Rubella (German measles) and BCG against tuberculsis 19
Hmestasis and Excretin Kidney Structure Hmestasis: Define as maintenance f a cnstant internal envirnment Functin: t keep cnditins in the bdy steady at levels where the reactins take place at a suitable rate. Cnditins include cncentratin f cmpunds and temperature Excretin: Define as the remval f the waste prducts f metablism frm bdy Functin: t remve waste prducts and keep them belw certain levels t cntrl water levels in bdy and thus keep cncentratin f chemical steady s that reactins ccur at a suitable rate Organs f excretin: Lungs: excrete CO 2 and water. Carbn dixide level as a cntrlling factr in breathing) Skin: excretes, water, salt and small amunts f urea Urinary system: water and urea Diagram Be able t draw and label the basic structure f the kidney shwing: crtex, medulla, pelvis, ureter, bladder and urethra. N.B. ureter and urethra must have crrect spelling Kidney cntrls cncentratin f bdy fluids: If slutins are t dilute lts f weak urine frmed called diuresis If slutins are t cncentrated the a small amunts f strng urine is prduced Be able t identify the sites f Filtratin: crtex, Re-absrptin: medulla and renal pelvis, Strage: urine gathers in pelvis, travels dwn ureter t bladder, Release: thrugh urethra Nephrn structure Diagram: Be able t label a diagram f nephrn and its bld supply including: renal artery, afferent arterile, glmerulus, Bwman s capsule, efferent arterile, prximal cnvluted tubule, lp f Henle, distal cnvluted tubule, cllecting duct, capillary bed and pelvis Frmatin f Urine Pressure increases in afferent arterile and glmerulus due t narrwing f bld vessels Fluid frced ut by pressure called ultra-filtratin, Cellular cmpnents t big t pass thrugh pres, Happens in Bwman s capsule, Liquid called glmerular filtrate, cntains glucse, amin acids, vitamins, salt, water and urea As Glmerular filtrate passes thrugh the prximal cnvluted tubule useful substances are reabsrbed e.g. glucse, amin acids, sme salts and water Reabsrbed int the bld by smsis, diffusin, and active transprt. Mre water reabsrbed in the Lp f Henle and the distal cnvluted tube. Urine passes int the pelvis f the kidney and t the bladder fr strage Out f bladder thrugh urethra (watch spelling). ADH actin Temperature cntrl ADH - Anti-diuretic hrmne Reabsrptin f water in the cllecting duct is under ADH influence ADH makes cllecting duct permeable s water reabsrbed int bld ADH s actin depends n the water cntent f the bld. Bld dilute ADH prductin drps and little water reabsrbed in cllecting duct - s lts passes int bladder diuresis Bld cncentrated ADH prductin increase and mre water reabsrbed int bld - s small amunts f strng urine Bdy t ht Sweating: evapratin f sweat cls bdy Bld diverted t skin surface when arteriles dilate Hairs lie flat Heat can escape Bdy t cld Bld kept away frm skin surface when arteriles cntract Hairs becme erect when erectr muscle cntracts s layer f insulating air trapped Heat can t escape Shivering prduces heat 20
Skin structure Diagram: Be able t draw and and label the fllwing structures: hair, hair rt, sebaceus gland, erectr muscle, sweat gland, sensry receptr, layer f subcutaneus fat, capillaries Fd The need fr fd as a surce f materials fr energy and tissue manufacture Elements present in fd: Six cmmn elements, (C, H, N, O, P, S), Five elements present in disslved salts (Na, Mg, Cl, K, Ca) Three trace elements (Fe, Cu, Zn). Cmbinatin f elements in different ratis t frm simple bimlecular units Carbhydrates surces f quick energy Fund is sugars, bread, pasta, ptates, fruit Cnsist f C x (H 2 O) y units Mnsaccharides cntain 1 sugar unit e.g. glucse Disaccharides cntain 2 sugar units e.g. sucrse Plysaccharides cntain many sugar units e.g. starch and cellulse in plants and glycgen in animals Lipids: Fund in dairy prduce e.g. butter and milk, and vegetable ils Unsaturated fats fund in plants less damaging t health Saturated fats fund in animals are rich in chlesterl which clgs arteries Cnsist f glycerl and 3 fatty acids Fats slid while ils are liquid at rm temperature Prteins: Fund in meat, fish and nuts Made f lng chains f amin acids Cntain elements C,H, O and N (als S) Vitamins: needed in small amunts fr healthy grwth and develpment C water sluble fund in citrus fruits and vegetables D - fat-sluble fund in dairy prduce and made in skin by sunlight Rughage: Prevents Cnstipatin by hlding water and keeps large intestine cntents sft Prevents bwel cancer Qualitative tests Starch: add idine slutin t ptat, bread r pasta turns blue/black Fat: rub butter r il n brwn paper permanent translucent stain Reducing sugar: add Benedict s slutin t glucse slutin, heat (but dn t bil) - turns frm blue slutin t red precipitate Prtein: add Biuret slutin t egg white and mix turns frm blue t purple Structural rles f bimlecules: Carbhydrate e.g. cellulse as a cmpnent f cell walls Prtein e.g. fibrus prteins as keratin in hair and skin, mysin in muscles Lipid e.g. cmpnent f cell membranes 21