proteins

Question 1

proteins

Answer 1

-complex organic nitrogenous compounds made of C, H, O, N, and S
-essential
-20% of body weight
-polypeptides are made of polymerization of AA through peptide bonds
>50 aa=proteins

Question 2

amino acids

Answer 2

composed of central C bonded to 4 groups
-amino gorup -NH2
-carboxyl group: -COOH
-Hydrogen
R group

Question 3

essential AAs

Answer 3

9 essentials
-cant synthesize them in body
-Leucine
isoleucine
lysine
methionine
phenylalanine
threonine
valine
tryptophan
histidine

Question 4

nonessential AA becoming essential

Answer 4

newborn, only 5 AA are non essential
metabolic pathways become more sufficient

Question 5

protein structure

Answer 5

-primary: determine by sequence of AA (unchanged by denaturing)
-secondary: h bonding of peptide backcone
-tertiary: 3D pattern of a protein due to side chain interactions
-quat- multiple chains

Question 6

classified by AA chains

Answer 6

dipeptide: 2
tripeptide: 3
polypeptide: more than 10
peptides: fewer than 50
proteins: more than 50

Question 7

DandA mouth and stomach

Answer 7

Chewing in mouth (mechanical digestion)
-chemical digestion begins in stomach
-Gastrin stimulates release of HCL
-denautre proteins and activates pepsinogen to pepsin

Question 8

DandA small intestine

Answer 8

Cholecystokinin (CCK)- peptide hormone of SI released from duodenal cells (stimulates digestion and stimulates release of pancreatic proteases)

-trypsin and chymotrypsin digest peptides to tri and di
-intestinal cells break them into amino acids
-absorbed through active transport
-transported to liver from the intestines by the hepatic portal vein

Question 9

assimilation

Answer 9

in liver
-used to synthesize new proteins
-converted to glucose
-energy
-released to bloodstream

Question 10

protein

Answer 10

4 cal/gram
-involved in blood clotting, fluid balance, hormone production, enzyme production, cell repair, connective tissues, neurotransmitters

Question 11

Protein turnover

Answer 11

body constantly degrades proteins (300 pro) we only take in 65-90
-some are recycled to make new AA
-some are eliminated\
-some metabolized energy
Insulin and GH= increase protein synthesis
glucagon and cortisol= increase protein degradation

Question 12

Deamination

Answer 12

removal of amine group
-loses an AA without transferring it to another molecule
-forms NH3
-C remanent=keto acid
-glucogenic=acid converted to glucose
ketogenic= acid to fats
-higher protein diets require more water

Question 13

nitrogen balance

Answer 13

+N= intake is bigger than excretion
-N= intake less than excretion
zero N balance= equilibrium

Question 14

transamination

Answer 14

forming NA AAs by transferring the N from one aa to a keto acid to form a new nonessential AA and a new keto acid

Question 15

protein intake

Answer 15

RDA= 0.8g/kg/day
10-35%

Question 16

digestibility

Answer 16

animal product= 90-99%
plant product= 70-90%
-soy and other legumes = >90%

Question 17

Complementary proteins

Answer 17

2 or more incomplete protein sources that in combination compensate for each other’s lack of AA

Question 18

high protein diet health effects

Answer 18

heart disease
cancer of colon, breast, kidneys, pancreas, and prostate
adult bone loss

Question 19

Kawshiorkor (protein energy malnutrition)

Answer 19

-severe protein deficiency from diet high in grains
-edema in legs, feet and stomach
-low muscle
-brittle hair-increase infection
-water and electrolyte imbalance

Question 20

Marasmus (protein energy deficiency)

Answer 20

severe deficiency in calories
-frail
-cannot stand
-older looking
-low Tb
-prone to dehydration