AA metabolism I

Question 1

what are the non-essential AA

Answer 1

alanine, aspartate, cystein, glutamate

Question 2

what does it mean if an AA is glucogenic

Answer 2

it is catabolized to pyruvate or a TCA cycle intermediate

Question 3

what does it mean if an AA is ketogenic

Answer 3

it is cataboluzed to acetyl or acetyl coa

Question 4

what AA are ketogeic

Answer 4

leucine and lysine

Question 5

what are the two steps of AA metabolism

Answer 5

1. transamination

2. oxidative deamination

Question 6

what occurs in AA transamination

Answer 6

NH2 groups are moved from an AA to an alpha ketoglutarate to form glutamate

Question 7

what is the cofactor for transamination

Answer 7

PLP (B6)

Question 8

what is the Keq for most transamination reactions

Answer 8

1

Question 9

in ALT, what is alanine turned into? aspartate?

Answer 9

pyruvate, OAA

Question 10

what enzyme is responsible for converting glutamate to alpha ketoglutarate? what are the cofactors

Answer 10

Glutamate DH; NAD or NADP

Question 11

D amino acids in the diet need to be oxidized by

Answer 11

FAD-dependent D-amino acid oxidase (DAO)

Question 12

what AA undergo non oxidative deamination? cofactor:

Answer 12

serine, threonine, cysteine, histidine (OH and SH groups) B6

Question 13

deamination of serine and threonine is carried out by

Answer 13

hydratase

Question 14

deamination of cysteine/cystine is carried out by

Answer 14

desulfurase

Question 15

what are the carbon skeletons of AA funneled into

Answer 15

pyruvate, acetyl coA, acetoacetyl CoA, a-ketoglutarate, succinyl coa, fumurate, oaa

Question 16

_____% of urea is filtered by colon

Answer 16

25

Question 17

what enzyme converts glutamate to glutamine for transport

Answer 17

glutamine synthetase and ATP

Question 18

what are the pathways to transport ammonia to the liver

Answer 18

glutamate/glutamine pathway

glucose/alanine cycle

Question 19

what does high NH4 increase

Answer 19

astrocyte glutamin, osmotic pressure, astrocyte swelling

Question 20

what does decreased glutamate do

Answer 20

low akg, low atp, astrocytrs cannot support neural funciton

Question 21

where does the urea cycle start

Answer 21

mito matrix

Question 22

ammonia and HCO3- is first converted to carbamoylphosphate by

Answer 22

CPS-1 and ATP

Question 23

where do the amino groups come from in the urea cycle

Answer 23

aspartate and fumarate

Question 24

what is defects of the urea cycle treated with

Answer 24

phenylbutyrate (absorbs glutamine)

Question 25

what AA are affected if someone has MSUD

Answer 25

ile, leu, val

Question 26

what accumulates in the blood with MSUD

Answer 26

branched chain AA

Question 27

If a patient has a build up of tyrosine what is expected? homogentisic acid?

Answer 27

type II tyrosinemia; AKU

Question 28

if a patient cannot convert phenylalanine to tyrosine they have

Answer 28

PKU

Question 29

if a patient has a defect tyrosinase, they have

Answer 29

albinism

Question 30

if a patent has a build up of maleylacetoacetate they have? fumaryloacetate?

Answer 30

type 3 tyrosinemia, type 1 tyrosinemia

Question 31

what are the symptoms of PKU

Answer 31

mousy smell, lack of pigmentation

Question 32

what is the treatment for PKU

Answer 32

restrict Phe, supplement Tyr

Question 33

PKU mimics a ______ deficinecy

Answer 33

B4

Question 34

what happens to the urine of people with AKU

Answer 34

Turns dark, also early arthritis