Metabolism

Question 1

acetyl CoA made available by…

Answer 1

oxidation of fatty acids, ketone bodies, monosaccharides, amino acids, ethanol

Question 2

cofactors of PDC

Answer 2

1. TPP (B1)
2. Lipoate
3. Coenzyme A (B5)
4. FAD (B2)
5. NAD (B3)

Question 3

PDC regulated by

Answer 3

increased ATP/AMP, NADH/NAD, acetyl CoA/CoA, PDK (-) and PDP (+), CO2

Question 4

starvation effect on PDC

Answer 4

increases transcription of PDK which inhibits PDC preventing glycolysis and promotes fat utilization so glucose can be used for brain

Question 5

AA that make a ketoglutarate

Answer 5

glutamate, histidine, proline, arginine

Question 6

AA that make fumarate

Answer 6

phenylalanine, tyrosine, aspartate

Question 7

AA that make succinyl CoA

Answer 7

methionine, SAM, valine, isoleucine, threonine

Question 8

AA that make acetyl CoA

Answer 8

leucine, isoleucine, lysine, tryptophan

Question 9

disorders of TCA due to problems in

Answer 9

a ketoglutarate dehydrogenase, succinate dehydrogenase, fumarase

Question 10

AA that make pyruvate

Answer 10

threonine, tryptophan, glycine, alanine, serine, cysteine

Question 11

3 ways to transport OAA to cytoplasm for gluconeogenesis

Answer 11

OAA –> PEP by PEPCK and transported by anion transporter
OAA –> malate by malate dehydrogenase –> cytoplasm
OAA –> aspartate –> cytoplasm –> back to OAA

Question 12

gluconeogenesis precursors

Answer 12

amino acids from proteins (mainly alanine)
lactate from RBC/muscle
glycerol from triacylglycerols

Question 13

short and medium chain FA enter mitochondrial matrix via..

Answer 13

monocarboxylate transporter

Question 14

B-oxidation inhibited by

Answer 14

malonyl-CoA and ATP/NADH

Question 15

w-oxidation

Answer 15

ER, uses cytochrome pf450, O2 and NADPH

Question 16

what converts acetoacetate to acetoacetyl-CoA?

Answer 16

succinyl-CoA

Question 17

adipose tissue can only make triacylglycerols when…

Answer 17

the cell is in the fed state and glycolysis is working to give DHAP

Question 18

sources of one carbon groups

Answer 18

serine, glycine, formaldehyde, histidine, formate

Question 19

2 rxns of B12

Answer 19

1. homocysteine to methionine

2. methylmalonyl CoA to succinyl CoA (no donation just rearrangement)

Question 20

SAM rxn

Answer 20

methionine + ATP –> SAM

Question 21

what’s needed to absorb B12

Answer 21

intrinsic factor

Question 22

what reactions need vitamin B6 (PLP)

Answer 22

making cysteine from homocysteine

ALT/AST

Question 23

routes for amine removal from amino acid

Answer 23

ALT/AST

oxidative deamination of glutamate via glutamate dehydrogenase

Question 24

urea cycle regulation

Answer 24

1. substrate availability (arginine) in feed-forward mechanism
2. allosteric activation of carbamoyl phosphate synthetase I (CPSI) by NAG
3. induction/repression of enzyme synthesis during high protein diet/starvation

Question 25

purine salvage pathway enzymes

Answer 25

adenine phosphoribosyltransferase | HGPRT

Question 26

what contributes nitrogen to urea

Answer 26

aspartate and ammonia

Question 27

what controls CPSTI

Answer 27

Arginine

Question 28

what inhibits complex 4 of ETC

Answer 28

CN, CO, H2S, sodium azide bind iron in heme of cytochrome aa of cytochrome oxidase

Question 29

what inhibits complex 3 of ETC

Answer 29

antimycin A and dimercaprol bind cytochrome c reductase in complex III

Question 30

barbituates and rotenone

Answer 30

inhibit transfer of electrons from iron-sulfur centers in Complex I to CoQ

Question 31

sources of primary ROS in cell

Answer 31

CoQ, oxidases peroxidases and oxygenases, ionizing radiation