1A Human Biology Food, Digestion and Associated Body Systems

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1A Human Bilgy Fd, Digestin and Assciated Bdy Systems Human Bilgy Fd, Digestin and Assciated Bdy Systems Fd Fd is ne f the basic human needs and the digestive

Fd is A necessary surce f energy A grwth material fr the bdy Balanced Diet: the crrect prprtin f each fd type in yur daily diet Cnstituents f a Balanced Diet: Fd

Carbhydrates Sugars quick energy surce Starch slwer lnger lasting surce f energy Fruit, jam Bread, pasta, Fibre absrbs water, aids peristalsis, prevents cnstipatin

Vitamins C prevents scurvy (bleeding gums) D prevents rickets (sft bnes) Oranges Dairy prducts 5.

1 1A Human Bilgy Fd, Digestin and Assciated Bdy Systems Human Bilgy Fd, Digestin and Assciated Bdy Systems Fd Fd is ne f the basic human needs and the digestive system enables the bdy t cnvert it int a frm that is mre suitable fr use. Fd is A necessary surce f energy A grwth material fr the bdy Balanced Diet: the crrect prprtin f each fd type in yur daily diet Cnstituents f a Balanced Diet: Fd Type Functin Surce 1. Carbhydrates Sugars quick energy surce Starch slwer lnger lasting surce f energy Fruit, jam Bread, pasta, Fibre absrbs water, aids peristalsis, prevents cnstipatin Vegetables, brwn bread 2. Prteins Grwth and Repair Lean meat, fish 3. Fats Energy Stre, insulatin Butter, ils, 4. Vitamins C prevents scurvy (bleeding gums) D prevents rickets (sft bnes) Oranges Dairy prducts 5. Minerals Irn used t make haemglbin fr red bld cells Red meat, green veg. Calcium strng teeth and bnes 6. Water Slvent carries glucse and ther substances arund the bdy Medium fr chemical reactins t take place in Water Fd Pyramid The fd pyramid shws us the relative amunts f each kind f fd that we shuld eat At each level there are a number f examples f typical fds f that type Fd Tests Starch: e.g. ptat, bread and pasta. Add idine slutin If starch present it turns blue black If n starch present it stays brwn. 1

stin and Assciated Bdy Systems Lipid [Fat r Oil]: e.g.

table il Rub n brwn paper, If lipid present brwn paper remains translucent Reducing

given in kiljules (kj) r kilcalries (kcal) fr each fd grup They are given per 100g (r as a %) and ften per

Digestin: The breakdwn f fd t make it suitable t be absrbed int the bdy Physical teeth and churning in the

2 1A Human Bilgy Fd, Digestin and Assciated Bdy Systems Lipid [Fat r Oil]: e.g. butter r vegetable il Rub n brwn paper, If lipid present brwn paper remains translucent Reducing Sugar: e.g. glucse Mix with Benedict s Slutin and heat gently (d nt bil) If reducing sugar present turns frm blue t red Prtein: e.g. egg white Add Biuret Slutin and shake If prtein present turns frm blue t vilet Fd Labels Energy values are given in kiljules (kj) r kilcalries (kcal) fr each fd grup They are given per 100g (r as a %) and ften per typical serving This enables ne t cmpare different fds Wmen need 2000 kcal and men 2500 kcal per day Digestin Digestin: The breakdwn f fd t make it suitable t be absrbed int the bdy Physical teeth and churning in the stmach Chemical by enzymes in the muth, stmach and small intestine Structure and Functin f Digestive System Part Functins Muth Teeth chp fd Saliva lubricates Amylase starts digestin f carbhydrates Oesphagus Pushes fd t stmach by peristalsis Stmach Mixes fd with HCl t kill bacteria Pepsin t break dwn prtein Liver Prduces bile t neutralise acid frm stmach Pancreas Prduces Amylase t digest carbhydrates Lipase t digest fats Prtease t digest prteins Insulin t cntrl bld sugar levels Small Intestine Absrbs digested fd Large Intestine Water balance Vitamins B and K prduced by symbitic bacteria 2

1A Human Bilgy Fd, Digestin and Assciated Bdy Systems Teeth Type Incisrs Canines Pre-Mlars Mlars Functin Flat and sharp fr cutting fd Pinted fr tearing fd Flat and ridged

used up in the reactin The Actin f Amylase n Starch Substrate: the substance the enzyme wrks n e.g.

Result: glucse present in tube cntaining amylase Cnclusin: amylase breaks starch dwn t glucse Respiratin: the release f energy frm digested fd Aerbic Respiratin Investigate

3 1A Human Bilgy Fd, Digestin and Assciated Bdy Systems Teeth Type Incisrs Canines Pre-Mlars Mlars Functin Flat and sharp fr cutting fd Pinted fr tearing fd Flat and ridged fr crushing and grinding fd Flat and ridged fr crushing and grinding fd Enzymes Enzyme: a bilgical catalyst Catalyst: substance that speeds up a chemical reactin but is nt used up in the reactin The Actin f Amylase n Starch Substrate: the substance the enzyme wrks n e.g. starch in ptat Enzyme: e.g. amylase in saliva Prduct: e.g. glucse Take tw samples f starch disslved in water Mix ne sample with amylase Place bth in a water bath at 37 C fr ten minutes Test bth fr glucse using Benedict s slutin Result: glucse present in tube cntaining amylase Cnclusin: amylase breaks starch dwn t glucse Respiratin: the release f energy frm digested fd Aerbic Respiratin Investigate the Cnversin f Chemical Energy in Fd t Heat Energy Put sme cld water in a test tube Take its temperature Light a crisp and hld it under the test tube f water After is has burned take the temperature f the water The temperature f the water has risen frm 16 C t 28 C Cnclusin Fd cntains lts f energy as chemical ptential energy This can be cnverted t heat energy by burning Aerbic Respiratin: The prcess f releasing energy frm fd using xygen Glucse (fd) + Oxygen = Carbn Dixide + Water + Energy Demnstrate the Prducts f Aerbic Respiratin 3

1A Human Bilgy Fd, Digestin and Assciated Bdy Systems Tests t Cmpare the Carbn Dixide Levels f Inhaled and Exhaled Air Using the apparatus shwn t the right Breathe in thrugh ne sample f limewater

breathing and circulatry systems Enable the transprt f xygen digested fd arund the bdy T prvide energy and grwth materials where they are required.

enter lungs Rings f cartilage keep the trachea pen Brnchi first divisin f trachea Brnchiles further divisins f brnchi Alveli air sacs cvered in a netwrk f capillaries xygen enters and carbn dixide

4 1A Human Bilgy Fd, Digestin and Assciated Bdy Systems Tests t Cmpare the Carbn Dixide Levels f Inhaled and Exhaled Air Using the apparatus shwn t the right Breathe in thrugh ne sample f limewater Breathe ut thrugh anther sample f water Results Limewater ges milky with exhaled air Stays clear with inhaled air Cnclusin Exhaled air cntains mre CO 2 Take careful nte f the psitins f the pipes The breathing and circulatry systems Enable the transprt f xygen digested fd arund the bdy T prvide energy and grwth materials where they are required. Structure and Functin Breathing System Nasal hairs filter incming air Epiglttis stps fd entering the airways Larynx [Vice bx] prduces sund by vibratin f the vcal crds Trachea windpipe allws air t enter lungs Rings f cartilage keep the trachea pen Brnchi first divisin f trachea Brnchiles further divisins f brnchi Alveli air sacs cvered in a netwrk f capillaries xygen enters and carbn dixide leaves bld Ribs prtect lungs and heart and play an imprtant rle in breathing Diaphragm sheet f muscle that separates the lungs and intestines. Helps draw air int lungs when it cntracts and flattens Gaseus Exchange Occurs in the alveli Surrunded by a netwrk f capillaries Oxygen diffuses int bld Carbn dixide and water diffuse ut f bld Mist surfaces make this easier Breathing Rate is the number f breaths per minute Effects f Smking Smke irritates the lungs causing inflammatin making lungs less efficient Increases breathing rate Causes brnchitis, cancer and heart disease 4

1A Human Bilgy Fd, Digestin and Assciated Bdy Systems Cmpsitin and Functins f Bld Circulatry System Cmpnent Descriptin Functin Plasma Liquid part f bld straw clured Transprts fd, hrmnes, bld cells,

red cells, Invlved in defence (fight infectins) Platelets Fragments f cells Invlved in cltting bld Structure and Functin f the Heart Left ventricle is strnger and thicker because it has t pump bld

Dexygenated bld enters right atrium frm vena cava Right atrium then cntracts Enters right ventricle thrugh valve Cntracts and passes int pulmnary artery thrugh valve Passes thrugh lungs picks up O 2,

5 1A Human Bilgy Fd, Digestin and Assciated Bdy Systems Cmpsitin and Functins f Bld Circulatry System Cmpnent Descriptin Functin Plasma Liquid part f bld straw clured Transprts fd, hrmnes, bld cells, Oxygen and carbn dixide Salts and urea Heat ( Helps regulate bdy temperature at 37 C) Red Bld cells Bicncave discs, n nucleus, Carry xygen arund the bdy cntain haemglbin White Bld Cells Larger tan red cells, Invlved in defence (fight infectins) Platelets Fragments f cells Invlved in cltting bld Structure and Functin f the Heart Left ventricle is strnger and thicker because it has t pump bld further (rund the whle bdy) than the right ventricle which nly has t pump it t the lungs and back Nte left and right are that f the wner f the heart nt as yu lk at it Passage f Bld thrugh the Heart Dexygenated bld enters right atrium frm vena cava Right atrium then cntracts Enters right ventricle thrugh valve Cntracts and passes int pulmnary artery thrugh valve Passes thrugh lungs picks up O 2, lses CO 2 Enters left atrium frm Pulmnary vein Enters left ventricle thrugh valve Cntracts and int Arta thrugh valve Arund bdy Differences between Arteries, Veins and Capillaries Artery Vein Capillaries Pulse N pulse Carries Bld away frm heart Carries bld twards heart Cnnects arteries t veins N valves Valves t prevent backflw Walls leak tissue fluid Thick walls Thin walls Walls n cell thick Small lumen Large Lumen Very narrw High pressure Lw pressure The prducts f digestin are absrbed int the bldstream and are thus circulated arund the bdy 5

1A Human Bilgy Fd, Digestin and Assciated Bdy Systems Factrs Affecting Human Pulse Rate Exercise Increases heart rate The fitter ne is the lwer heart rate tends t be and the faster it returns t nrmal

Recrd pulse at rest using first and secnd fingers n wrist Cunt numb

6 1A Human Bilgy Fd, Digestin and Assciated Bdy Systems Factrs Affecting Human Pulse Rate Exercise Increases heart rate The fitter ne is the lwer heart rate tends t be and the faster it returns t nrmal Health Illness tends t increase pulse rate Stress Increases pulse rate The Effect f Exercise n the Pulse and Breathing Rate. Recrd pulse at rest using first and secnd fingers n wrist Cunt number f pulse in 15 secnds and multiply by fur t get rate per minute Average pulse rate fr an adult at rest is 70 b.p.m. Recrd the breathing rate at rest Cunt the number f breaths in 15 secnds and multiply by fur t get rate per minute D vigrus exercise Recrd the pulse and breathing rates as befre Taking a Pulse Results: Exercise increases bth pulse and breathing rates A balance f bth regular exercise and diet prmtes gd health Exercise results in increased pulse and breathing rates t supply extra xygen fr the increase in respiratin required t release the extra energy needed fr the exercise Bdy Temperature Nrmal human bdy temperature is 37 C Illness may cause an increase in bdy temperature as the bdy requires extra energy t fight the infectin Excretin Excretin: the remval f metablic wastes frm the bdy Egestin: the remval f undigested fd frm the bdy as faeces Prducts f Excretin: CO 2, water and urea Organ Lungs Kidneys Skin Substances Excreted Carbn dixide and water in breath Water, salts and urea in urine Salt and water in sweat Urinary System Renal Artery brings bld with impurities frm heart t kidney Renal Vein brings purified bld t the vena cava and thence back t the heart Kidney Filters the bld and remves urea and excess water Ureter brings urine frm the kidney t the bladder Bladder stres urine Urethra carries urine frm the bladder t utside the bdy 6

Biology 30S Unit Test Review: Digestion

Biology 30S Unit Test Review: Digestion Bilgy 30S Unit Test Review: Digestin Test utline: Multiple Chice: 10 Questins, 1 mark each. Shrt Answer: 5 Questins (answer 3 f them), 5 marks each. Lng Answer: 2 Lng Answer Questins, 10 marks each. Tasks