AAW - High-yield rate limiting steps in biochemistry

Question 1

Glycolysis

Answer 1

Enzyme: Phosphofructokinase-1 (PFK-1)

positive regulators: AMP, fructose-2,6-bisphosphate

neg reg: ATP, citrate

Question 2

Gluconeogenesis

Answer 2

Enzyme: Fructose-1,6-bisphosphatase (PEP-ck also plays a role by getting oxaloacetate out of the krebbs cycle by converting it into phosphoenolpyruvate)

neg reg: AMP, fructose-2,6-bisphosphate

Question 3

TCA cycle

Answer 3

isocitrate dehydrogenase

pos reg: ADP

neg reg: ATP, NADH

Question 4

Glycogenesis

Answer 4

glycogen synthase

Glucose-6-phosphate ⊕, insulin ⊕, cortisol ⊕
Epinephrine ⊝, glucagon ⊝

Question 5

Glycogenolysis

Answer 5

Glycogen phosphorylase

Epinephrine ⊕, glucagon ⊕, AMP ⊕
Glucose-6-phosphate ⊝, insulin ⊝, ATP ⊝

Question 6

HMP shunt

Answer 6

Glucose-6-phosphate dehydrogenase (G6PD)

NADP+ ⊕
NADPH ⊝

Question 7

De novo pyrimidine

synthesis

Answer 7

Carbamoyl phosphate synthetase II

ATP ⊕, PRPP ⊕
UTP ⊝

Question 8

De novo purine

synthesis

Answer 8

Glutamine-phosphoribosylpyrophosphate
(PRPP) amidotransferase

AMP ⊝, inosine monophosphate (IMP) ⊝,
GMP ⊝

Question 9

Urea cycle

Answer 9

Carbamoyl phosphate synthetase I

N-acetylglutamate ⊕

Question 10

Fatty acid synthesis

Answer 10

Acetyl-CoA carboxylase (ACC)

Insulin ⊕, citrate ⊕
Glucagon ⊝, palmitoyl-CoA ⊝

Question 11

Fatty acid oxidation

Answer 11

Carnitine acyltransferase I

Malonyl-CoA ⊝

Question 12

Ketogenesis

Answer 12

HMG-CoA synthase

Question 13

Cholesterol synthesis

Answer 13

HMG-CoA reductase

Insulin ⊕, thyroxine ⊕
Glucagon ⊝, cholesterol ⊝