Proteins and Amino Acids

proteins

organic compounds made of C,H,O,N and sometimes S

proteins are made of

amino acids

how do cells use proteins

synthesize them for a part of their life cycle

proteins are highest where

in the muscle tissue

proteins are important for

structure, movement and function

The amount of protein required in the diet for an animal depends on

the animals physiology

what happens to the amount of protein required for young growing animals

declines gradually to maturity

pregnancy and lactation do what to the protein requirement of an animal

increase the protein requirement

proteins vary in

chemical composition, shape, size, and physical properties

there are 10 essential animo acids that the body

cannot produce

left handed vs right handed animo acids

left- naturally occuring

right- stereoisomers (bacterial and some naturally occuring)

the amino acid structure is made up of

an amino group and a carboxylic group with a Carbon in the center and a side chain

proteins can be classified by

their shape, solubilities in water, salt, acids, bases, and alcohol

globular proteins

soluble in water, dilute acids, bases and alcohol

fibrous proteins

insoluble in water, resistant to digestive enzyme

conjugated proteins

contain wide array of compounds that are non proteins

where are lipoproteins found

in the blood and membranes of animal cells

lipoprotein

protein lipid complex

myelin

lipoprotein abundant in nervous system as a sheath around nerve fibers

erythrocyte

red blood cells

glycoprotein

protein and carbohydrate complexes

chondroitin

carbohydrates that are complexed with proteins in cartilage, tendons, and skin

essential amino acids

amino acids that are not synthesized in the tissues in sufficient amounts to meet the body’s needs

what are the 12 essential amino acids

phenylalanine, tryptophan, histidine, Valine, Isoleucine, Arginine, Glycine, Threonine, Methionine, Leucine, Proline, and Lysine (PVT THIM GALL)

Non essential amino acids

amino acids that are synthesized in adequate amount in the tissues 

essential amino acids

Alanine, Cystine, Hydroxyproline, Asparagine, Glutamic acid, Proline, Aspartic acid, Glutamine, Serine

Functions of Proteins

components of cell membranes, found in muscle/skin/hair, serve in gene expression,

protein is found as

collagen in connective tissue

elastin in ligaments and artery walls

keratin- proteins of hair/horns/claws

muscle

blood protein 

digestive enzyme that breaks down proteins

pepsin

catabolism

degradation (broken down) in animal tissues

anabolism

synthesis of proteins in animal tissues

digestible protein

vanishing from the ingested feed as it passes through the GI tract 

where are proteins absorbed in ruminants vs nonruminants

ruminants- rumen and omassum

non ruminants- lumen of the small intestine

absorption of amino acids is done by 

active transport

amino acids in the GI tract can come from 3 main sources

diet, nitrogen recycling, synthesized by microbes, bacteria and protozoa

feces coprophagy

the eating of feces

what organ is principal for degrading all animo acids

liver (microbes)

after absorption of amino acids

synthesis of tissues, enzymes and hormones

use of carbon skeleton for energy

deamination or transamination 

making milk protein, egg, meat, etc

deamination vs transamination

removal or transfer of an amino acid

urea cycle

metabolic process in protein in protein metabolism and elimination of N

what happens to urea in the urea cycle

excreted in urine (main route of N excretion)

what operates the urea cycle

liver

amino acid antagonism

refers to the growth depression that can be supplementation with an amino acid structurally the same 

amino acid toxicity

adverse effect of an Amino Acid that cannot be overcome by supplement

Amino acid imbalance

any change in the portion of dietary amino acid that has an adverse effect

biological value

the percent of N absorbed from the GI tract that is available for productive body functions (eggs have the highest value)

net protein value 

measures the percentage of ingested nitrogen that is retained in the body for growth and maintenance 

net protein utilization

measures efficiency of growth by comparing body N content of animals resulting from feeding a test protein

protein efficiency ratio

body weight gain by protein consumed