3b. Nutrition and Macromolecules Flashcards
(24 cards)
what is an enzyme?
A protein catalyst that increases the rate at which a chemical reaction proceeds
list the 6 classes of nutrients
carbohydrates, proteins, lipids, vitamins, minerals, water
what is an essential nutrient? Give 2 examples
chemicals that must be taken into the body, because we cannot make them ourselves
amino acid/fatty acid/water
recommended amount of carbohydrates per day
45-65% of daily intake of kilocalories
recommended amount of lipids per day
20-35% or less of daily intake of kilocalories
list the three monosaccharides
glucose
fructose
galactose
(GFG)
list three disaccharides
sucrose
lactose
maltose
(SLM)
2 examples of a polysaccharise
glycogen
starch and cellulose
explain carbohydrate absorption
- a polysaccharide chain is digested by saliva in the oral cavity and pancreatic amylase in the duodenum.
- disaccharide chain is digested by sucrose in the intestine.
- monosaccharide chain (glucose) is absorbed into the blood via the villi/microvilli in the intestine.
- glucose is transported to the liver via the hepatic portal vein.
4 ATP functions
warmth, movement, brain activity, muscle contraction
where and how is excess glucose stored?
stored as glycogen, in the muscle and liver cells
describe the composition of an amino acid
anime group (NH2)
carboxyl group (COOH)
hydrogen
side group
what is the function of proteins?
regulate bodily functions
what is a complete protein?
food that contains enough of all 9 essential amino acids
what is an incomplete protein?
leafy green veg, grains, legumes - have to mix all of these to get all the AA’s
explain protein absorption
- protein is digested by trypsin in the stomach, the protein is now a polypeptide.
- the polypeptide is digested by trypsin in the duodenum.
- peptides an individual amino acids are absorbed into the blood
why are lipids broken down when ingested?
to release energy
what determines how saturated a lipid is?
how many H atoms on each chain
what is an unsaturated fatty acid?
contains one or more double bonds in the carbon chain, so there is less H atoms, more relaxed structure
explain lipid absorption
- Lipid (triglycerides) digestion begins in the duodenum
- Bile from the gall bladder emulsifies lipids
- Lipase from the pancreas causes further breakdown
- Short chain fatty acids (monoglycerides) are absorbed into the lymphatic system via lacteals.
- Lipids are stored in the adipose tissue and liver until needed.
what ions are actively transported during water absorption?
sodium, potassium, calcium, magnesium, phosphate
what are the water soluble vitamins?
B
C
what are the lipid soluble vitamins?
A
D
E
K
functions of minerals
Membrane potential and action potential
Add mechanical strength to bones and teeth
