rate determining enzymes of metabolic processes

Question 1

glycolysis (for this and all, name the enzyme and the regulators)

Answer 1

PFK-1.

incr. : AMP, fructose-2,6-bisphosphate
decr. : ATP, citrate

Question 2

gluconeogenesis

Answer 2

fructose-1,6-bisphosphatase

incr. : ATP, acetyl CoA
decr. AMP, fructose-2,6-bisphosphatase

Question 3

TCA cycle

Answer 3

isocitrate dehydrogenase

incr. by ADP
decr. by ATP and NADH

Question 4

glycogenesis

Answer 4

glycogen synthesis.

incr. by glucose-6-P, insulin, cortisol.
decr. by epinephrine, glucugon

Question 5

glycogenolysis

Answer 5

glycogen phosphorylase

incr. by epinephrine, glucagon, AMP
decr. by glucose-6-P, insulin, ATP

Question 6

HMP shunt

Answer 6

glucose-6-phosphate dehydrogenase.

incr. by NADP. decr. by NADPH

Question 7

de novo pyrimidine synthesis

Answer 7

carbamoyl phosphate synthetase II

Question 8

de novo purine synthesis

Answer 8

PRPP amidotransferase
(glutamine-phosphoribosylpyrophosphate amidotransferase)
decr. by AMP, IMP (inosine monophosphate), and GMP

Question 9

urea cycle

Answer 9

carbamoyl phosphate synthestase I

incr. by N-acetylglutamate

Question 10

fatty acid synthesis

Answer 10

acetyl-CoA carboxylase
incr. by insulin and citrate
decr by glucagon and palmitoyl-CoA

Question 11

ketogenesis

Answer 11

HMG-CoA synthetase

Question 12

cholesterol synthesis

Answer 12

HMG-CoA reductase

incr. by insulin and thyroxine
decr. by glucagon and cholesterol

Question 13

fatty acid oxidation

Answer 13

carnitine acyltransferase I

incr. by malonyl-CoA

Question 14

production of pyruvate

Answer 14

pyruvate kinase (from phosphoenolpyruvate)

incr. by fructose 1,6-BP
decr. by ATP and alanine (which builds up when pyruvate decarboxylase is deficient, so it probably suggests too much alanine around)