Nutrition Biology

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Biology Revision Notes – Form 4
Food 1 2 3 4 contains Water Proteins – carbon, oxygen, nitrogen & sometimes sulphur Carbohydrates – carbon, oxygen, hydrogen Fats – carbon, hydrogen, oxygen USES, ETC ENZYMES, HORMONES, BLOOD PROTEINS Used to supply the body with energy MONO SACCHARIDES DI SACCHARIDES POLYSACCHARIDES Used to store energy, insulate against cold = blubber ©www.bioclix.org

GOOD SOURCES PROTEINS (CHONS) POULTRY, FISH, BEEF, MILK, CHEESE, LIVER, MILK CARBOHYDRATES MILK, SOFT DRINKS, JAM, HONEY, (CHO) FRUIT, STARCH = POTATOES, RICE FATS (CHO) DAIRY PRODUCTS, MARGARINE, LARD, COOKING OIL, FRIED FOOD

Amount of food we need per day depends on 1) body size 2) how active we are 3) Important chemicals ü ü ü ü ü

how fast we are growing

Glucose – simple sugar – C6H12O 6 Fructose – simple sugar - C6H12O 6 Sucrose – double sugar (fructose + glucose) – C12H22O 11 Maltose – double sugar (glucose + glucose) - C12H22O 11 Starch – polysaccharide (maltose + maltose + maltose + ….)

Food tests
FOOD Protein Glucose/ monosaccharides Starch Fat METHOD Copper sulphate + sodium hydroxide Few drops benedict’s solution & heat in waterbath Add few drops iodine Ethanol + water & shake +VE RESULT Purple Orange precipitate Blue black Cloudy white

Vitamins and Minerals
VITAMIN A C D GOOD SOURCES Cod liver oil, carrots, spinach, milk Fresh fruit & vegetables Eggs, liver, white fish, sun, cheese, milk NEEDED FOR Growth, eyesight, good skin DEFICIENCY DISEASE Reduced growth, eye disorders

Healthy gums, healing of wounds Scurvy Build the minerals calcium & phosphorous into strong bones and teeth 1

Rickets in children

MINERAL Nitrogen
Magnesium

GOOD SOURCES

NEEDED FOR To make proteins Make chlorophyll molecules

DEFICIENCY DISEASE Pale green leaves at top, dry yellow leaves at bottom Leaves turn yellow from bottom upwards, slow growth Rickets in children Muscular weakness, loss of minerals from bone Anaemia

Calcium Phosphoro us Iron

Milk, cheese, bread, flour products Most foods Bread, flour, meat, green vegetables

For strong bones & teeth, blood clotting, working of muscles Strong bones & teeth. Part of ATP To make haemoglobin

Enzymes
Breaker enzyme

1. Enzyme approaches substrate Builder enzyme

2. Substrate fits in active site

3. Enzyme converts substrate into product

4. Products released

1. Enzyme approaches substrate

2. Substrate fits in active site

3. Enzyme converts substrate into product

4. Product released

REMEMBER - Enzymes are specific and affected by pH and Temperature

Respiration
There are 2 types of respiration 1 Aerobic respiration 2 AEROBIC RESPIRATION C6H12O6 + 6O2 → 6CO2 + 6H2 O +2898 kJ of energy Oxygen needed More energy released Glucose completely broken down Anaerobic respiration ANAEROBIC RESPIRATION Glucose→alcohol+carbon dioxide + energy No oxygen needed Less energy released Glucose not completely broken down 2

Anaerobic respiration in muscle cells Glucose→ lactic acid C6H12O6→ 2CH3CHOHCO2H As the air enters our lungs it must be changed in 3 ways 1 warmed 2 moistened 3 filtered and cleaned Remember small animals like the hydra and amoeba need no special organs. Gas exchange takes place by diffusion through the body wall or across cell membrane.

Energy released = 0.83KJ/g of glucose

Gas exchange takes place at the alveolus

Excretion
Water balance = balance between water lost and water gained Water lost = sweat, breath, faeces, urine, osmosis Water gained = food, drink, osmosis, respiration Osmoregulation = Methods used for controlling the osmotic potential of the liquids inside and outside their cells. Human urinary system

Responsible for osmoregulation and removing waste.

3

The blood is cleaned by 2 processes 1 Filtration 2 Reabsorption Substances removed = water, urea, ammonia Substances reabsorbed = glucose, proteins, water ©www.bioclix.org

The Skin
The skin is made up of mainly 2 layers – outer epidermis...
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