Proteins & Amino Acids Flashcards
protein definition
compounds composed of carbon, hydrogen, oxygen, and nitrogen atoms arranged into strands of amino acids
some amino acids also contain ____ atoms
sulfur
amino acid definition
building blocks of protein
what is an amino acid made of
amino group and acid group attached to a central carbon that has a distinctive side chain
what determines amino acid function
the way they’re lined up
3 types of amino acid
valine
leucine
tyrosine
dipeptide
2 amino acids bonded together
tripeptide
3 amino acids bonded together
polypeptide
10 or more amino acids bonded together
oligopeptide
intermediate strand of 4-10 amino acids bonded together
AA sequence
attracts or repels to give it the direction it will fold into
essential amino acids
amino acids that the body cannot synthesize in sufficient amounts to meet physiological need
aka. indispensable amino acids
9 known
types of essential amino acids (1-5)
histidine
isoleucine
leucine
lysine
methionine
types of essential amino acids (6-9)
phenylalanine
threonine
tryptophan
valine
non-essential amino acids
body can synthesize from consumed essential amino acids
11 known
conditionally essential amino acid
normally a non-essential amino acid that becomes essential in special circumstances
must be consumed in diet
cysteine
glutamine
functions of proteins in the body
enzymes
antibodies
fluid & electrolyte balance
acid/base rxns
hormones
enzyme
protein catalysts make rxn faster/more efficient
facilitates chemical rxns without being changed in the process
all enzymes are proteins
antibodies
large proteins of blood and body fluids produced in response to the body being invaded by antigens
purpose is to inactivate the invaders to protect the body
adequate protein is needed to produce antibodies
antigen
unfamiliar molecules (mostly proteins) that stimulate an immune response
hormones
chemical messengers secreted by glands in the body in response to altered conditions
travels to one or more target tissues/organs and stimulates specific responses to restore normal conditions
some hormones are proteins, some are sterols
3 types of body fluids
intracellular
interstitial (between cells)
intravascular
fluid and electrolyte balance
maintenance of the necessary amounts and types of fluids and minerals in each compartment of body fluids
serum albumin
maintains fluid id blood vessels
edema
swelling of body tissue caused by leakage of fluid from vessels and accumulation of fluid in interstitial spaces
acid base balance
balance between acid and base concentrations in body fluids and blood
body produces acids and bases during normal functions (carried to lungs & kidneys through blood)
if blood is too acidic or basic than proteins denature
denature
chance in a protein’s shape
past a certain point, denaturation is irreversible
pH
concentration of hydrogen ions
acidosis
too much acid in blood & body fluids
alkalosis
too much base in blood & body fluids
buffers
compounds that can reversibly combine with hydrogen ions to keep a solution’s acidity or alkalinity constant
how much protein do we need a day?
normal people 0.8 g / kg / day
athletes 1.2 g / kg / day
body builders/injured 1.5 g / kg / day
dietary amino acids
used primarily for protein synthesis
not stored like fat or carbohydrates
what happens to excess protein?
degrades and produces urea
who shouldn’t get protein?
chronic kidney disease w/ no dialysis
liver failure w/ encephalopathy
nitrogen balance
amount of nitrogen consumed vs. excreted in a given period of time
lab tech can estimate protein in a sample of food, body tissue, or poop by measuring nitrogen in it
nitrogen equilibrium
zero nitrogen balance
N in = N out
positive nitrogen balance
N in > N out
kids, pregnant women, sick people (anorexics, trauma, burns)
negative nitrogen balance
N out > N in
anorexics, trauma, burns, HIV/AIDS
how to figure out your protein need
find body weight in lbs then convert to kg
multiply kg by 0.8 g
protein synthesis after activity
increases
7-28 gm protein per day gained during …
muscle building phase of training
what type of diet spares protein?
carbohydrate rich
BCAA
can be used instead of glucose directly into muscle tissue
what depletes glycogen
endurance with aerobic activity of moderate intensity and long duration
effect of degree of training?
higher degree uses less protein
complete protein
contains all amino acids essential in human nutrition in adequate amounts
incomplete protein
lacking or low in one or more of the essential amino acids
high-quality protein
easily digestible complete protein
limiting amino acid
essential amino acid that is present in dietary protein in the shorted supply relative to the amount needed for protein synthesis in the body
mutual supplementation
combining two incomplete protein sources to form a more complete protein
aka. complementary proteins
complementary proteins
two or more proteins whose amino acid assortments complement each other
supply the amino acid the other is lacking
vegetarian diets need…
adequate nutrient/energy intakes
balance
variety
moderate fat, sodium, alcohol & caffeine
vegetarian diets are generally…
lower in fat & cholesterol
concerns with vegetarian diets
energy needs
B12
vitamin D
zinc & iron (soy inhibits zinc absorption)
calcium
types of vegetarians
lacto-ovo
lacto
semi-vegetarian
vegan
lacto-ovo vegetarian
include milk & eggs
no meat, fish, shellfish, poultry
lacto-vegetarian
include milk
no eggs, meat, fish, shellfish, poultry
semi-vegetarians
include some, but not all animal products
usually no meat, but will eat fish, shellfish, poultry
vegan
exclude all animal-derived foods
