Amino Acids

Question 1

amino acids are the building blocks of ______

Answer 1

proteins

Question 2

proteins are polymers of amino acids linked by a ______

Answer 2

peptide bond

Question 3

a long chain of amino acids formed this way is a _____

Answer 3

polypeptide

Question 4

what are the functions of amino acids?

Answer 4

Building blocks of protein, functioning of body, blood clotting, skeletal muscle + skin, locomotory movement, hormones are formed by amino acids, albumin to transport proteins in blood + maintain circulatory system

Question 5

an amino acid has a _____ group, _______ group, ______ and ______ group

Answer 5

amino, carboxylic, hydrogen, and R

Question 6

how to classify amino acids
- varies species to species

Answer 6

• location
• acidity
• phenyl group?
• occurrence in protein
• polarity of r group
• nutrient value

Question 7

how are amino acids absorbed?

Answer 7

active transport by the micro villi/villi of the small intestine

Question 8

T/F: There is an active transport system for neutral amino acids and one for basic amino acids

Answer 8

true

Question 9

__ Form of amino acids are absorbed preferentially to __ form

Answer 9

L;D

Question 10

Neutral _____ inhibit basic amino acids
Basic ______ inhibit neutral amino acids

Answer 10

can; cannot

Question 11

T/F: some amino acids compete with each other for transport

Answer 11

true

Question 12

what happens after amino acids are absorbed?

Answer 12

tissue protein synthesis
synthesis of enzymes, hormones, and other metabolites
deamination or transamination and use of the carbon skeleton for energy

Question 13

what is deamination?

Answer 13

excess amino acids being converted into urea in the liver with enzymes to maintain homeostasis

Question 14

How are proteins synthesized and degraded?

Answer 14

presence of nucleic acids required for protein synthesis, DNA controls the formation of RNA, ribosomal RNA is the site of protein formations, transfer RNA carries specific AA to the ribosome to interact with mRNA, mRNA determines the sequence of AA

Question 15

Where are proteins synthesized?

Answer 15

ribosomes (rRNA)

Question 16

What carries the AA to the ribosomes?

Answer 16

tRNA

Question 17

What determines the sequence of AA, determining what proteins are made and their quantity?

Answer 17

mRNA

Question 18

Deamination involves the _______ of the amino group from the carbon skeleton; entrance of the amino group into the ________

Answer 18

removal; urea cycle

Question 19

Transamination involves the _______ of the amino group from one AA to the carbon skeleton of a keto acid

Answer 19

transfer

Question 20

The ability of animal tissues to synthesize amino acids from other compounds as the basis for their clarification as _________ or _______________

Answer 20

essential; nonessential

Question 21

Conditionally essential amino acids

Answer 21

Amino acids that can become essential in certain physiologic conditions
ex. taurine in cats, proline in young pigs, tyrosine in people with PKU

Question 22

What are the differences between amino acids and imino acids?

Answer 22

Amino: building block of proteins, single bond, carboxylic, amine group, R group, hydrogen, ex. lysine
Imino: contains imino and carboxylic group together, double bond, ex. proline

Question 23

Is cysteine considered essential?

Answer 23

No, if the body has sulfur, it can make cysteine

Question 24

Methionine supplies methyl groups for _______
Choline is a precursor of ________ _________ and ________

Answer 24

creatine; homocysteine, cystine, ad cysteine

Question 25

Is methionine considered essential?

Answer 25

yes, animals cannot synthesize it

Question 26

Where the urea cycle take place?

Answer 26

partly in the mitochondria and cytoplasm

Question 27

What is the main route of nitrogen excretion in birds?

Answer 27

uric acid

Question 28

What is the difference between urea and uric acid excretion?

Answer 28

Urea: product of amino acid catabolism (breaking down AAs), plasma concentration reflects the amount or protein in diet, enters renal tubules through glomerular filtration, 50% reabsorbed, rest is excreted Uric acid: product of nucleic acid metabolism, enters renal tubules through glomerular filtration, 100% reabsorbed, 1-% secreted and excreted

Question 29

Urea is excreted in the ______ and is the chief route of _________ excretion in __________

Answer 29

urine; nitrogen, mammals

Question 30

T/F: there is no evidence of a metabolic requirement for dietary protein, but there is for amino acids

Answer 30

True

Question 31

______ omnivores require specific dietary amino acids (essential amino acids) whereas ___________ herbivores are able to utilize nonprotein nitrogen for microbial amino acid synthesis in the lower part of the Gi tract

Answer 31

nonruminant; nonruminant

Question 32

Adult _______ can depend entirely on nonprotein nitrogen in the diet by virtue of rumen microbes

Answer 32

ruminants

Question 33

What is the most common of all nutrient deficiencies? Why?

Answer 33

N or amino acids, most energy sources are low in protein and protein supplements are expensive

Question 34

What are some deficiencies of essential amino acids?

Answer 34

anorexia, reduced growth rate, reduced or negative N balance, reduced efficiency of feed utilization, reduced serum protein concentration, reduced birth weight of young, anemia, fat accumulation in the liver, edema, reduced milk production, reduced synthesis of certain enzymes and hormones

Question 35

Tryptophan deficiency=

Answer 35

cataracts

Question 36

threonine or methionine deficiency=`

Answer 36

fatty liver

Question 37

lysine defciency in birds=

Answer 37

abnormal feathering

Question 38

taurine deficiency in cats=

Answer 38

cardiomyopathy

Question 39

glycine and proline deficiency=

Answer 39

abnormal growth in chickens

Question 40

amino acid antagonism

Answer 40

growth depression that can be overcome wit supplementation

Question 41

amino acid toxicity

Answer 41

used when the adverse effect of an amino acid in excess cannot be overcome with supplementation of another amino acid

Question 42

amino acid imbalance

Answer 42

any change in the proportion of dietary amino acids that has an adverse effect preventable by a relatively small amount of the most limiting amino acids

Question 43

antagonism differs from imbalance in that the supplemented amino acids ________ to be limited

Answer 43

does not need

Question 44

fecal analysis method

Answer 44

Measurement of free amino acids in the plasma of animals at intervals following a meal of the test protein that allows a means of estimating the availability of one or more amino acids

Question 45

microbiological assay