B4. Nutrition Flashcards
define nutrition
taking in of nutrients which are
organic substances/ mineral ions,
containing raw materials or energy
for growth and tissue repair, absorbing and assimilating them.
structure of carbonhydrate
contains: C, H, O
simple sugar - glucose
complex sugar - sucrose
complex carbohydrate - starch
structure of protein
contains: C, H, O, N, (S)
long-chain molecules of smaller molecules- amino acids
bond - peptides
structure of fats
contains: C, H, O
1 molecule of glycerol attach 3 fatty acids
small molecules are joined together to make long chain molecules
sugar → complex carbohydrates, e.g: starch, glycogen
amino acids → proteins
test for biological molecules
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
test for starch
1 half fill test-tube of substance
2 add 2 drops of iodine
3 +ve result: blue/black
test for reducing sugar
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 —
define egestion
passing out of food that has not digested or absorbed
define ingestion
taking in substances via mouth
define digestion
breaking down of large insoluble food molecules
→ water soluble molecules
by mechincal/ chemical process
define absortion
movement of digested food through the wall of the intestines to blood
define assimilation
absorbed food molecules become part of cells
structure of teeth
enamel - hard outer layer
dentine - softer
cement layer fixed the root of tooth to a bony socket
pulp cavity - contains nerves and blood vessels
what is enamel
the outer layer of crown of tooth, the part above gum
what is dentine
softer part than enamel
what is cement
fixes the root of tooth into a bony socket of jaw
describe tooth decay
caused by bacteria in plaque which changes
sugar → acid that attack enamels and dentine of tooth
stages of tooth decay
1, particles of sugary food left inbetween teeth/plague contains bacteria which changes sugar → acid
- acid attack enamel on surface and start off decay
- when enamel worn away,acid will attack dentine
- acid reaches pulp cavity, will be painful and cause severe tooth ache, gums red and swollen
tooth uses
incisors - bitting/ cutting
canines - piercing/ tearing
premolars/ molars - grinding/chewing
define peristalsis
wave of muscular contraction
describe digestion of food in stomach
-produce gastric juice
protein → polypeptide
hydrochloric acid - kills bacteria,optimum for protease
the function of pancrease
produces
amylase: starch → maltose
trypsin: protein, polypeptides → peptides
lipsin: fat → fatty acid, glycerol
abt bill
liver - produces bile
gall bladder - stores bil
pH for enzyme in intestines
emulsifies into smaller water soluble goubles
how the small intestine is adapted for absorbtion
- 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
the function of small intestine
duodenum: food is mixed with gastric juice+bile
ileumL digested food is absorbed into blood and lymp
the function of large intestine
colon - water is absorbed
rectum - feaces is stored
anus - feaces exit
describe the structure of villus
capillary - amino acids/glucose molecules are absorbed
lacteal - fatty acids/glycerol are absorbed
→carries by hepatic portal vein
define photosynthesis
process by which plants manufacture carbohydrates from raw materials using energy from light
manufactures carbs
define photosynthesis(simplified)
manufactures carbs, using raw materials by light
photosynthesis equation
6CO2 + 6H20 →C6H12O6 + 6O2
carbon dioxide + water -→ glucose + oxygen
describe the stages of test for starch
- dip leaf in boiling water → easier to extract chlorophyll
- boil leaf in ethanol for 10m → extract chlorophyll
- wash leaf in cold water → remove ethanol/soften/ rehydrates leaf
- add drops of iodine to leaf → test for starch
investigation of light intenstity on photosynthesis
- cut a length of 5cm pondweed
- put paperclip on pondweed to stop floating
- put a lamp close to plant and measure distance between plant/lamp
- count the number of bubbles released over 5m. repeats several times and get avr
- repeat procedure:lamp at different distances from plant
investigation of CO2 on photosynthesis
*control variables
- 5 test tube with different mass of sodium hydrocarbonate added
- light intensity and temperature must be kept constant
describe water intake
plant absorbs water into root by osmosis. for
- reactant in photosynthesis
- keeps cell turgid
- cools leave by evaporation
- transport dissolved materials
describe CO2 intake
leaves have large SA and stomata to allows CO2 exchange
importance of magnesium ions
chlorophyll synthesis
required for photosynthesis
→ affect plant growth
→ changes yellow
importance of nitrates ions
protein synthesis
required for making new leaves
affect foot yield/plant growth
overuse: eutrophication
describe eutrophication
→ fertilisers leak into water
→ rapid growth for water plant
→ these plant die/ decomposition needs O2
→ less O2 for other organism/ die
→ pond becomes stagnantstomata, palisade and mesophyll cells – gas exchange
- 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 - palisade mesophyll : photosynthesis
CO2 diffuses in for photosynthesis
O2 diffuses out - spongy mesophyll
- spongy layer wit airspace, allows CO2 to diffuses in
distribution of chloroplasts – photosynthesis
upper epidermis: transparent
palisade mesophyll : contains lots of chlorplast where photosynthesis occurs
prevention of water loss
cuticles: waterproof layer/ no evaporation
stomata
