Chapter 23

Question 1

ketogenic AA’s enter CAC as ?

Answer 1

Acetyl CoA

Question 2

Proteins are broken down into AA’s by ?

Answer 2

proteolytic enzymes

Question 3

amino acid catabolism pathway

Answer 3

AA + a-ketoglutarate > a-ketoacid + glutamate. glutamate + NAD+ + H2O > NADH + NH4+

Question 4

aspartate aminotransferase catalyzes reaction of ? to form ?

Answer 4

aspartate and a-KG to form OAA and glutamate

Question 5

PLP transamination 2 steps

Answer 5

replace amino group of AA with ketone oxygen to form alpha keto acid. A secondalpha keto acid accepts amino group.

Question 6

most AA degradation takes place in ?

Answer 6

liver

Question 7

excess nitrogen is metabolized by ? in liver

Answer 7

glutamate dehydrogenase

Question 8

? and ? can be directly deaminated using dehydratases

Answer 8

serine and threonine

Question 9

Two ways NH4+ is transferred back to liver

Answer 9

glutamine synthetase and glucose-alanine cycle

Question 10

glutamaine synthetase reaction catalyzed

Answer 10

NH4+ + glutamate + ATP > Glutamine + ADP

Question 11

Glucose alanine cycle, NH4+ muscle to liver transport

Answer 11

NH4+ combines with pyruvate to form alanine which can transport to liver. a-KG reacts with alanie in liver to form glutamate and pyruvate. glutmate releases NH4+

Question 12

CH2 and NH4+ form ? which combines with ornithine to form citrulline to start the urea cycle in the mitochondrial matrix

Answer 12

carbamoyl phosphate

Question 13

Urea and TCA cycles are linked at ?

Answer 13

argininosuccinate

Question 14

arginosuccinase deficiency can be overcome by ?

Answer 14

supplying excess Arg in diet

Question 15

3 carbon AA’s degraded to ?

Answer 15

pyruvate

Question 16

5 carbon AA’s degraded to ?

Answer 16

a-KG

Question 17

? AA’s are degraded to glutamate

Answer 17

pro, Arg, His

Question 18

? AA’s are degraded to succinyl CoA

Answer 18

Met. Val, Ile