AminoAcidMetabolism

Question 1

8 Dietary Essential Amino Acids + 2 other semi-essential amino acids

Answer 1

Phenylalanine, Valine, Tryptophan, Threonine, isoleucine, Methionine, Leucine, Lycine Histadine, Arginine (optimal growth)

Question 2

Synthesis of Dietary Non-Essential Amino Acids - Alanine

Answer 2

amination of pyruvate

Question 3

Synthesis of Dietary Non-Essential Amino Acids - Aspartate

Answer 3

amination of oxaoloacetate

Question 4

Synthesis of Dietary Non-Essential Amino Acids - Asparagine

Answer 4

amidation of aspartate

Question 5

Synthesis of Dietary Non-Essential Amino Acids - Cysteine

Answer 5

from Serine & homocysteine

Question 6

Synthesis of Dietary Non-Essential Amino Acids - Glutamate

Answer 6

amination of alpha-ketoglutarate

Question 7

Synthesis of Dietary Non-Essential Amino Acids - Glutamine

Answer 7

amidation of glutamate ( aminate carboxyl side chain)

Question 8

Synthesis of Dietary Non-Essential Amino Acids - Glycine

Answer 8

from Serine

Question 9

Synthesis of Dietary Non-Essential Amino Acids - Tyrosine

Answer 9

Hydroxylation of phenylalanine

Question 10

Synthesis of Dietary Non-Essential Amino Acids - Proline

Answer 10

from gluatmate or ornithine (by a series of reactions)

Question 11

Synthesis of Dietary Non-Essential Amino Acids - Serine

Answer 11

from 3-phosphoglycerate (glycolytic intermediate)

Question 13

Glucogenic Amino Acids via pyruvate

Answer 13

alanine, cysteine, glycine, & serine

Question 14

Glucogenic Amino Acids via alpha-ketoglutarate

Answer 14

arginine, glutamate, glutamine, histidine, proline

Question 15

Glucogenic Amino Acids via oxaloacetate

Answer 15

aspartate & asparagine

Question 16

Glucogenic Amino Acids via succinyl-CoA

Answer 16

methionine, threonine, & valine

Question 17

Glucogenic & Ketogenic Amino Acids via succinyl-CoA & acetyl-CoA

Answer 17

Isoleucine

Question 18

Glucogenic & Ketogenic Amino Acids via fumarate & acetyl-CoA

Answer 18

phenylalanine & tryosine

Question 19

Glucogenic & Ketogenic Amino Acids via pyruvate & acetyl-CoA

Answer 19

tryptophan

Question 20

Ketogenic Amino Acids via acetyl-CoA

Answer 20

leucine and lysine

Question 21

Glucogenic Amino Acids

Answer 21

those amino acids whose metabolism yeilds an intermediate of the citric acid cycle or gluconeogenesis

in diabetic animal, metabolism of these amino acids will result in elevation of blood glucose levels

Question 22

Ketogenic Amino Acids

Answer 22

those amino acids whose metabolism yeilds acetyl-CoA

in diabetic animal, metabolism of ketogenic amino acids will result in an elevation of circulating ketone bodies

Question 23

Alanine aminotransferase (ALT)

Answer 23

alanine + alpha-ketoglutarate –> pyruvate + glutamate

reversalbe reaction but works in direction of glutamate synthesis (Nitrogen collector) from alanine

elevated levels lead to liver damage

Question 24

Aspartate Aminotransferase (AST)

Answer 24

oxaolacetate + glutamate –> aspartate + alpha-ketoglutarate

exception to the rule= AST –> AST transfers amino group from glutamate to aspartate (used as the source of nitrogen in the urea cycle)

increase levels of AST in plasma –> sign of cardiac ischemia

Question 25

Breakdown of Amino Acids

Answer 25

Transamination –> oxidative deamination

Question 26

Synthesis of amino acids

Answer 26

Reductive amination –> transamination

Question 28

Transamination

Answer 28

amino acid + alpha ketoglutarate –> keto acid + glutamate; the acceptor is alpha ketoglutarate to yeild keto acid and glutamate (glutamate is then subject to oxidative deamination in the reaction catalyzed by glutamate dehydrogenase)

Question 29

Oxidative Deanimation

Answer 29

glutamate + NAD+ + H2O –> alpha ketoglutarate + NH3 + NADH + H+; uses glutamate dehydrogenase

Question 31

Transaminase/Amino Transferase

Answer 31

uses pyridoxal phosphate (derived from Vitamin B) as coenzyme; the acceptor is pyruvate with the formation of alanine; exception is Aspartate aminotransferase

Question 32

Urea Components

Answer 32

formed from a nitrogen of ammonia, nitrogen from aspartate, and a carbon from bicarbonate

Question 34

Disease Associated with Urea Cycle

Answer 34

Less than optimal amount of enzymes for breakdown of ammonia–Synthesis of Urea – examples: Phenylketonuria, Maple Syrup Urine disease, alkaptonuria

Question 35

Phenylketonuria

Answer 35

deficient in PHENYLALANINE HYDROXLASE or in atypical cases the defect is in dihydrobiopterin reductase; accumulation of phenylketones; excretion in the urine of phenylketones; mental retardation; light colored hair and skin (Scandanavia - first discovered bc blond, blue eyes) Reason for this light complexion is not alot of phenylalanine being transfered to tyrosine (formation of melanin); autosomal recessive condition; therapy=change of diet; can’t get ride of Phenylalanine from diet but need to limit for vital function (apartame is depeptide with phenylalanine)

Question 36

Maple Syrup Urine Disease

Answer 36

deficiency in branched chain alpha-keto acid dehyrogenase, which is important for branched chain aa metabolism (leucine, Isoleucine, and valine) need to have some of these aa in diet but limited; odor of urine is like maple syrup; mental retardation

Question 37

Alkaptonuria

Answer 37

deficient in homogentisate oxidase (an enzyme in catabolism of tyrosine); relatively benign-joint problems later in life; accumulation of homogenistic acid-which darkens the urine upon standing due to the acids polymerization; very rare but known for along time

Question 38

Amino Acid Metabolites - Tyrosine

Answer 38

dopamine, epinephrine and norepinephrine, melanin (protection from UV rays), throxine and triidothyronine (thyroid hormones)

Question 39

Amino Acid Metabolites - Tryptophan

Answer 39

Serotonin

Question 40

Amino Acid Metabolites - Histidine

Answer 40

Histamine (thru simple decarboxylation)

Question 41

Amino Acid Metabolites - Glutamate

Answer 41

gamma-amino butyrate (GABA)

Question 42

Glycine and Argnine

Answer 42

Creatine (phosphorylated to make creatine phosphate, a high energy molecule)

Question 43

Arginine (intermdeiate of Urea Cycle)

Answer 43

Polyamines (putrescine, spermidine and spermine) Nitric Oxide

Question 44

Transfer of one carbon units:

Answer 44

the major carrier of methyl group is S-adenosylmethionine (SAM); involve a derivative of tetrahydrofolate serves as a carrier of one carbon units at the levels of methanol, formaldehye and formic acid(important in nucleotide synthesis); biotin is a carrier of carbon dioxide (pyruvate decarboxylase; fatty acid synthesis when forming malonyl CoA)

Question 45

Sulfonamides

Answer 45

Structural analogs of p-aminobenzoic acid which is requried by bacteria for synthesis of tetrahydrofolic acid; used for bacteria chemotherapy

Question 46

Methotrexate

Answer 46

Structural analog of dihydrofolate (intermediate in synthesis of tetrahydrofolate) inhibits the reduction of dihydrofolate to tetrahydrofolate; treatment of psoriasis; cancer chemotherapy