Amino Acid Synthesis and Degradation

Question 1

What are sources of amino acids?

Answer 1

proteins, body proteins or one you eat. excess nitrogens.

Question 2

What are the essential amino acids

Answer 2

PVT TIM HALL

phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, histidine, arginine, leucine, lysine

Question 3

essential vs. nonessential

Answer 3

essential - must eat in diet

nonessential - body can make from another source

Question 4

3 phosphoserine to serine

Answer 4

phosphoserine phosphatase

Question 5

3 phoshphydroxy pyruvate to 3 phosphoserine

Answer 5

transamination and PLP

Question 6

3 phosphoglycerate into 3 phosphoydroxy pyruvate

Answer 6

3 phosphopyruvate dehydrogenase

Question 7

Describe formation of serine

Answer 7

starting with 3phosphoglycerate (intermediate of glycolysis)

1) 3 phosphoglycerate via 3 phosphopyruvate dehydrogenase (using NAD+/NADH) becomes 3 phosphohydroxy pyruvate

2) 3 phospho hydroxy pyruvate via transamination reaction and PLP becomes 3 phoshposerine

2) 3 phosphoserine via phosphoserine phosphatase becomes serine

Question 8

What intermediate of glycolysis is a precursor of serine?

Answer 8

3 phosphoglycerate

Question 9

What starting material makes serine?

Answer 9

glucose

Question 10

formation of glycine

Answer 10

starts with serine; hydroxymethyl transferase and PLP

Question 11

serine hydroxymethyltransferase

Answer 11

main way for producing tetrahydrofolate derivatives. requires PLP as a cofactor.

Question 12

describe body catabolism of methionine

Answer 12

methionine becomes homocyteine via the methylation cycle. SAM gives a methyl group and S- adenosyl methionine becomes homocysteine

Question 13

Draw homocysteine

Answer 13

1 carbon longer than cysteine

Question 14

describe synthesis of cysteine from serine and methionine

Answer 14

using the sulfur of methionine to become sulfur of cysteine. the rest of cysteine (carbons and nitrogen) comes from serine.

Question 15

Where does the sulfur come from in cysteine?

Answer 15

it comes from methionine

Question 16

Where do the nitrogens of cysteine come from

Answer 16

they come from serine

Question 17

Cystathionine-β-synthase

Answer 17

homocysteine reacts with serine makes cystatione. PLP is required to make cysteine

Question 18

Cystathionase

Answer 18

PLP required. Cystathione breaks apart. one is cysteine and one part is alpha ketobutyrate. Loss of nitrogen.. comes off as an ammonium.

Question 19

propionyl CoA carboxylase

Answer 19

proprionyl Coa (3 carbons) becomes methyl malonyl (4 carbons) Biotin, CO2, and ATP required.

Question 20

methylmalonyl coA mutase

Answer 20

requires vitamin B12 as a cofactor

methylmalonyl becoming succinyl CoA

propionyl becomes methyl malonyl

Question 21

what cofactor is required by methylmalonyl CoA mustase

Answer 21

vitamin B12

Question 22

which amino acids lead to propionyl group?

Answer 22

VITM

valine, isoluecine, threonine, and methionine

Question 23

formation of alanine?

Answer 23

alanine transaminase (ALT), which converts L-glutamate and pyruvate into α-ketoglutarate and L-alanine. requires PLP

Question 24

formation of aspartate

Answer 24

oxaloacetate to aspartate via aspartate transamination and PLP

Question 25

formation of arginine

Answer 25

from aspartate; arginine synthetase; comes from glutamine side chain

Question 26

pyruvate carboxylase

Answer 26

pyruvate into oxaloacetate

Question 27

sources of propionyl CoA

Answer 27

- cholesterol is turned into an unconjugated bile salt - priopionic acid made in the colon - fatty acid oxidation

Question 28

describe synthesis of glutamate from glucose and

Answer 28

glucose to pyruvate (via glycolysis) pyruvate becomes acetyl coA via pyruvate dehydrogenase pyruvate becomes oxaloacetate via the pyruvate carboxylase reaction oxaloacetate and acetyl coA via citrate synthase go into TCA cycle alpha ketoglutarate to glutamate via glutamate dehydrogenase. ammonium ion added via glutamine synthetase reaction and this can be made glutamine

Question 29

2 amino acids made from glutamate

Answer 29

proline and arginine (via glutamate semialdehyde (arginine / ornithine/urea cycle)

Question 30

aromatic amino acids

Answer 30

tyrosine, tryptophan, phenylalanine

Question 31

how to synthesize tyrosine from phenyl alanine

Answer 31

hydroxylation reaction. BH4 tetrahydrobioterin is required as second reducing agent (first reducing agent is phenylalanine) and the oxidizing agent is O2

Question 32

what is the biological cause of PKU disease? phenylketonuria

Answer 32

genetic mutation, can't turn phenylalanine into tyrosine. phenylalanine builds to a dangerous level. aspartame contains it. classical = genetic mutation of phenylalanine hydroxylase nonclassical - dihydrobioterine reductase mutation, doesn't have enough BH4 to hydroxylate aromatic amino acids

Question 33

Six entry points for mainstream metabolism

Answer 33

pyruvate, acetyl CoA ``` alpha ketoglutarate succinyl coA (VITM) ``` fumarate oxaloacetate

Question 34

branched chain amino acids and their degredation

Answer 34

liver caells cannot break down but muscle cells can transamination reactions

Question 35

why does the liver not break down branched chain amino acids?

Answer 35

branched chain aminoacid transaminase - mmuscle cells have lots of this and liver does not

Question 36

branched chain ketoacid dehydrogenase complex BCKADH

Answer 36

an alphaketoacid gets oxidized, decarboxylated and attached to coenzyme A needs thiamine pyrophosphate, lipoic acid, and FAD.

Question 37

three enzymes that require lipoic acid as a cofactor

Answer 37

alpha ketoglutarate dehydrogenase pyruvate dehydrogenase branched chain ketoacid dehydrogenase

Question 38

enzymes with thiamine pyrophosphate in active site

Answer 38

alpha ketoglutarate dehydrognase pyruvate dehydrogenase branched chain ketoacid dehydrogenase transketolase

Question 39

amino acid precursor for carnitine

Answer 39

lysine and methionine in the form of SAM

Question 40

glutathione perioxidase requires which cofactor

Answer 40

selenium

Question 41

amino acid precursor for glutathione

Answer 41

glutamate, cysteine, and glycine

Question 42

conjugation of bile salts

Answer 42

taurine and glycine

Question 43

amino acid required for synthesis of taurine

Answer 43

sulfur containing cysteine amino acid

Question 44

NAD nicotinamide adenine dinucleotide made from

Answer 44

tryptophan

Question 45

Tri-iodotyronine

Answer 45

T3

Question 46

Tetra-iodotyronine

Answer 46

T4

Question 47

thyroid hormones

Answer 47

tyrosine

Question 48

heme

Answer 48

glycine and succinyl coA is the intermediate

Question 49

creatine amino acid precursor

Answer 49

glycine and arginine and methionine

Question 50

epinephrine

Answer 50

requires methionine SAM

Question 51

melanins

Answer 51

tyrosine

Question 52

serotonin

Answer 52

tryptophan

Question 53

melatonin

Answer 53

tryptophan and methionine SAM

Question 54

Succinyl coA sources

Answer 54

VITM valine, isoleucine, threonine, methionine

Question 55

histamine

Answer 55

histidine

Question 56

gamma amino butyric acid

Answer 56

glutamate

Question 57

nitric oxide

Answer 57

arginine

Question 58

purine nucleotides

Answer 58

glutamine, glycine, aspartate

Question 59

pyrimidine nucleotides

Answer 59

glutamine and aspartate