B4. Nutrition

Question 1

define nutrition

Answer 1

taking in of nutrients which are
organic substances/ mineral ions,
containing raw materials or energy
for growth and tissue repair, absorbing and assimilating them.

Question 2

structure of carbonhydrate

Answer 2

contains: C, H, O
simple sugar - glucose
complex sugar - sucrose
complex carbohydrate - starch

Question 3

structure of protein

Answer 3

contains: C, H, O, N, (S)
long-chain molecules of smaller molecules- amino acids
bond - peptides

Question 4

structure of fats

Answer 4

contains: C, H, O

1 molecule of glycerol attach 3 fatty acids

Question 5

small molecules are joined together to make long chain molecules

Answer 5

sugar → complex carbohydrates, e.g: starch, glycogen

amino acids → proteins

Question 6

test for biological molecules

Answer 6

starch w/ iodine → blue/black

simple sugar w/ benedict’s solution → blue/ yellow/ green= alot of reducing sugar

protein → biuret reagnant → purple

fat w/ ethanol → forms cloudy emulsion

Question 7

test for starch

Answer 7

1 half fill test-tube of substance
2 add 2 drops of iodine
3 +ve result: blue/black

Question 8

test for reducing sugar

Answer 8

1 put a known volume of exact
2 place a beaker on heat proof mat
3 carefully half fill beaker with boiling water
4 add same volume of benedict’s solution to test tube and put into hot beaker
5 +ve result: from blue to —

Question 9

define egestion

Answer 9

passing out of food that has not digested or absorbed

Question 10

define ingestion

Answer 10

taking in substances via mouth

Question 11

define digestion

Answer 11

breaking down of large insoluble food molecules
→ water soluble molecules
by mechincal/ chemical process

Question 12

define absortion

Answer 12

movement of digested food through the wall of the intestines to blood

Question 13

define assimilation

Answer 13

absorbed food molecules become part of cells

Question 14

structure of teeth

Answer 14

enamel - hard outer layer
dentine - softer
cement layer fixed the root of tooth to a bony socket
pulp cavity - contains nerves and blood vessels

Question 15

what is enamel

Answer 15

the outer layer of crown of tooth, the part above gum

Question 16

what is dentine

Answer 16

softer part than enamel

Question 17

what is cement

Answer 17

fixes the root of tooth into a bony socket of jaw

Question 18

describe tooth decay

Answer 18

caused by bacteria in plaque which changes

sugar → acid that attack enamels and dentine of tooth

Question 19

stages of tooth decay

Answer 19

1, particles of sugary food left inbetween teeth/plague contains bacteria which changes sugar → acid

2. acid attack enamel on surface and start off decay
3. when enamel worn away,acid will attack dentine
4. acid reaches pulp cavity, will be painful and cause severe tooth ache, gums red and swollen

Question 20

tooth uses

Answer 20

incisors - bitting/ cutting
canines - piercing/ tearing
premolars/ molars - grinding/chewing

Question 21

define peristalsis

Answer 21

wave of muscular contraction

Question 22

describe digestion of food in stomach

Answer 22

-produce gastric juice
protein → polypeptide
hydrochloric acid - kills bacteria,optimum for protease

Question 23

the function of pancrease

Answer 23

produces

amylase: starch → maltose
trypsin: protein, polypeptides → peptides
lipsin: fat → fatty acid, glycerol

Question 24

abt bill

Answer 24

liver - produces bile
gall bladder - stores bil
pH for enzyme in intestines
emulsifies into smaller water soluble goubles

Question 25

how the small intestine is adapted for absorbtion

Answer 25

- very large SA - thin lining( 1 cell thick) so digested food can easily cross the wall into blood and lymph - has villi, that has microvillus

Question 26

the function of small intestine

Answer 26

duodenum: food is mixed with gastric juice+bile | ileumL digested food is absorbed into blood and lymp

Question 27

the function of large intestine

Answer 27

colon - water is absorbed rectum - feaces is stored anus - feaces exit

Question 28

describe the structure of villus

Answer 28

capillary - amino acids/glucose molecules are absorbed lacteal - fatty acids/glycerol are absorbed →carries by hepatic portal vein

Question 29

define photosynthesis

Answer 29

process by which plants manufacture carbohydrates from raw materials using energy from light manufactures carbs

Question 30

define photosynthesis(simplified)

Answer 30

manufactures carbs, using raw materials by light

Question 31

photosynthesis equation

Answer 31

6CO2 + 6H20 →C6H12O6 + 6O2 | carbon dioxide + water -→ glucose + oxygen

Question 32

describe the stages of test for starch

Answer 32

1. dip leaf in boiling water → easier to extract chlorophyll 2. boil leaf in ethanol for 10m → extract chlorophyll 3. wash leaf in cold water → remove ethanol/soften/ rehydrates leaf 4. add drops of iodine to leaf → test for starch

Question 33

investigation of light intenstity on photosynthesis

Answer 33

1. cut a length of 5cm pondweed 2. put paperclip on pondweed to stop floating 3. put a lamp close to plant and measure distance between plant/lamp 4. count the number of bubbles released over 5m. repeats several times and get avr 5. repeat procedure:lamp at different distances from plant

Question 34

investigation of CO2 on photosynthesis | *control variables

Answer 34

1. 5 test tube with different mass of sodium hydrocarbonate added 2. light intensity and temperature must be kept constant

Question 35

describe water intake

Answer 35

plant absorbs water into root by osmosis. for - reactant in photosynthesis - keeps cell turgid - cools leave by evaporation - transport dissolved materials

Question 36

describe CO2 intake

Answer 36

leaves have large SA and stomata to allows CO2 exchange

Question 37

importance of magnesium ions

Answer 37

chlorophyll synthesis required for photosynthesis → affect plant growth → changes yellow

Question 38

importance of nitrates ions

Answer 38

protein synthesis required for making new leaves affect foot yield/plant growth overuse: eutrophication

Question 39

describe eutrophication

Answer 39

``` → fertilisers leak into water → rapid growth for water plant → these plant die/ decomposition needs O2 → less O2 for other organism/ die → pond becomes stagnant ```

Question 40

stomata, palisade and mesophyll cells – gas exchange

Answer 40

1. stomata - opens in sunlight allows CO2 diffuses in for photosynthesis O2 diffuses out water vapour diffuses out -close at night/hot/dry weather → prevent water loss 2. palisade mesophyll : photosynthesis CO2 diffuses in for photosynthesis O2 diffuses out 3. spongy mesophyll - spongy layer wit airspace, allows CO2 to diffuses in

Question 41

distribution of chloroplasts – photosynthesis

Answer 41

upper epidermis: transparent | palisade mesophyll : contains lots of chlorplast where photosynthesis occurs

Question 42

prevention of water loss

Answer 42

cuticles: waterproof layer/ no evaporation | stomata