Rate Determining Enzymes

Question 1

Glycolysis

Answer 1

Phosphofructokinase-1

Fructose-6-Pi —> Fructose 1,6 BisPi

Regulation: (+) F23BP, AMP
(-) ATP and Citrate

Question 2

Gluconeogenesis

** Where does the ATP that drives gluconeogenesis come from?

Answer 2

Fructose 1,6 Bisphosphatase

Fructose 1,6 BPi —> Fructose 6 Pi

(-) F 23 BP

**Oxidation of Fatty acids

Question 3

TCA cycle

Answer 3

Isocitrate Dehydrogenase

Isocitrate —> Alpha Ketoglutarate

(+) ADP
(-) NADH

Question 4

Glycogen Synthesis

Answer 4

Glycogen Synthase

(-) when phosphyrolated due to ^[cAMP] and ^ [PKA]

Question 5

Glycogenolysis

Answer 5

Glycogen Phosphorylase

(+) when phosphorylated due to ^[cAMP] and ^[PKA] due to glucagon and epinepherine

Question 6

HMP Shunt (Pentose Phosphosphate Pathway)

What does this enzyme cause production of?

Answer 6

Glucose 6 Phosphate Dehydrogenase

G-6-P —> Ribulose 5 Phosphate

Generates NADPH necessary to maintain reduced glutothionine

Question 7

Fatty Acid Synthesis

Answer 7

Acetyl-CoA carboxylase

Question 8

Fatty Acid Oxidation

Answer 8

Carnitine Acetyltransferase 1 (CAT-1)
Fatty Acyl CoA + Carnitine —> Fatty Acyl Carnitine + CoA

(-) Malonyl CoA inhibits CAT 1 during FA synthesis to avoid a futile cycle.
(+) ^ Fatty Acid Concentration

Question 9

Ketogenesis

Answer 9

HMG-CoA synthase

Question 10

Cholesterol Synthesis

Answer 10

HMG CoA reductase