amino acid metabolism urea cycle

Question 1

pyruvate decarboxylase won’t function unless ___ ___ is abundant to give high levels of oxaloacetate (anaploritic)

Answer 1

acetyl CoA

Question 2

not all organisms use ___ ___ the same way

Answer 2

amino acids

Question 3

amino acids can undergo ____ catabolism

Answer 3

oxidative (pulling out electrons)

Question 4

we can very quickly interconvert with the addition of an amine group in place of a ____ carbon

Answer 4

carbonyl

Question 5

cuts protein into peptides in the stomach

Answer 5

pepsin

Question 6

cut proteins and larger peptides into smaller peptides in the small intestine

Answer 6

trypsin and chymotrypsin

Question 7

degrade peptides into amino acids in the small intestine

Answer 7

aminopeptidase

Question 8

enzymes of peptides within the body are active in different parts of the body due to ___ specificity

Answer 8

pH

Question 9

the amino acids destined for oxidation end up where

Answer 9

liver

Question 10

in the liver dietery amino acids coming from the bloodstream ____ acts as a nitrogen sink

Answer 10

glutamate

Question 11

the glutamate in the liver is formed from ______ by an aminotransferase (takes NH3 off amino acid)

Answer 11

alpha-ketoglutarate

Question 12

the reaction with glutamate as a nitrogen sink happens where

Answer 12

cytosol

Question 13

there is a cofactor in the alpha-ketoglutarate to glutamate reaction; what is it?

Answer 13

PLP

Question 14

PLP come from __ and are covalently attached to lysine (long amino acid which allows for more movement)

Answer 14

B6

Question 15

aminotransferase is an example of ____ ____ mechanism

Answer 15

ping-pong

Question 16

removing an amino group in cytosol but dropping it off in the mitochondria

Answer 16

transdeamination

Question 17

glutamate gets moved from cytosol to mitochondrial matric and gets converted back to alpha-ketoglutarate by ____

Answer 17

glutamate dehydrogenase

Question 18

the only enzyme that can use either NAD+ or NADP+ is

Answer 18

glutamate dehydrogenase

Question 19

glutamate dehydrogenase is activated by ADP why (GTP inhibits it)

Answer 19

energy is low in the body so proteins needs to be broken down for energy

Question 20

when a reaction uses the energy of ATP to proceed forward ATP is apart of a

Answer 20

group transfer

Question 21

___ is a nontoxic way to transport ammonia to the liver

Answer 21

glutamine

Question 22

in liver mitochondria, glutamine release its __ by glutaminase and goes back to glutamate

Answer 22

NH4

Question 23

Glutamine will have two ___ groups and both will be unloaded and released; the second release is catalyzed by __ ____ instead of glutaminas e

Answer 23

NH4; glutamate dehydrogenase

Question 24

muscle uses the _____ ____ cycle to break down amino acids when exercising

Answer 24

glucose-alanine

Question 25

pyruvate from the glycolysis cycle gets converted in the muscle to alanine then to __ ___ which gets into the liver

Answer 25

blood alanine

Question 26

what enzyme catalyzes pyruvate to alanine

Answer 26

alanine aminotransferase

Question 27

the first step of the urea cycle __ ATP are consumed

Answer 27

2

Question 28

first step: carbamoyl phosphate synthetase I incorporates first amino acid along with ____

Answer 28

bicarbonate

Question 29

what is the end product of urea cycle: step 1: part 1

Answer 29

carbamoyl phosphate

Question 30

step 1; part 2 of urea cycle carbamoyl phosphate is activated by ornithine to give you ____; catalyzed by ___ ___ (gets taken out after this from mitochondrial matrix to cytosol)

Answer 30

citrulline; orthinine transcarbamoylase

Question 31

in step 2 od urea cycle citrulline is combined with ____ and uses an ATP; end product is

Answer 31

aspartate; argininosuccinate

Question 32

argininosuccinate gets converted to ____ + arginine; which will be put back into citric acid cycle

Answer 32

fumarate

Question 33

if fumarate is put back in citric acid cycle, it then goes to malate to oxaloacetate. If thats the case how many ATP come from that and then what is the net ATP gain from urea

Answer 33

2.5 ATP; net expense is .5 ATP