Protein and Amino Acids (15) Flashcards
What are proteins?
chains of amino acids
essential amino acids
not produced sufficiently by body (9 total)
non-essential amino acids
produced in sufficient amounts by body (11 total)
How many amino acids do humans need?
20
How does denaturation of proteins occur?
exposure to heat, acids, bases, alcohol
Good denaturation
-cooked eggs
-stomach acid opens protein structure for digestion
Bad denaturation
-fevers
-heavy metals can destroy body proteins (corrosive actions)
Role of HCl in digestion
-unfolds proteins in stomach
-converts pepsinogen to pepsin
Role of pepsin in digestion
-cleaves (breaks) large polypeptides into smaller polypeptides
Role of pancreatic proteases
-break polypeptides into smaller structures in small intestine
Role of intestinal di/tri-peptidases
-complete breakdown into amino acids in intestine
Where are amino acids absorbed?
into the blood stream
what is protein used for in the body?
-building material
-maintenance of osmotic pressure
-synthesis of substances (hemoglobin, enzymes, hormones)
How is glucose stored?
glycogen
How is fat stored?
triglyceride
How is protein stored?
Cannot be! Excess protein consumed out
What is a significant property of (some) amino acids in starvation?
Can be converted into glucose
Digestibility % of dietary protein
-animal (>90%)
-legume (80%) beans, lentils
-grains/plants (60-90%)
complete proteins
-contains all the essential amino acids
-meat, fish, poultry, cheese, eggs, milk, many soybean products
incomplete proteins
-lack some essential amino acids
-plants (beans, nuts)
grains do not contain sufficient…
lysine (liars those farmers)
legumes do not contain sufficient…
methionine (do beans taste good after meth?)
what are complementary proteins?
grains and legumes together (complete protein)
dietary protein requirements in population
-sedentary (0.8g/kg)
-strength maintenance (1.2-1.4)
-strength gain (1.6-1.8)
-endurance (1.2-1.4)
-weight restricted (1.4-1.8)
-infant (6 month) (2.2)
-child (1-6) (1.2)
who may be in a positive nitrogen balance (retain more than excrete)
-growing child
-pregnant women
-person building muscle
who may be in nitrogen equilibrium
normal healthy individuals
who may be in negative nitrogen balance (lose more than take in)
-trauma patient
-astronaut
(loosing tissue)
Danger of individual AA supplements
-may be contaminated
-interfere with other EAA absorption
whey protein
-20% whey and 80% casein
-generally good
can eating extra protein make muscles grow larger?
-NO, sufficient is necessary, excess may lead to body fat
Kwashiorkor
-protein deficiency
-swelling in limbs and stomach
-devastating wasting
-“moon face” and edema (swelling)
Marasmus
-protein and calorie deficiency
-extreme emaciation (abnormally thin/weak)
-“m”ore (protein and calorie)
danger of protein excess
1) high fat (red meat)
2) high protein results in Ca loss in urine
3) dehyrdation
