Topic 10 - Gluconeogenesis, Homolactic & Alcoholic Fermentation

Question 1

What are the 3 irreversible steps in Glycolysis & what enzymes that catalyze the reverse reaction in Gluconeogenesis (GNG)?

Answer 1

The 3 irreversible steps in Glycolysis have different enzymes that catalyze the reverse reaction in GNG: 1a) Pyruvate Carboxylase: Pyruvate + ATP –> OAA

1b) PhosphoEnolPyruvate CarboxyKinase: OAA –> PEP (both reverse PK reaction).
2) Fructose bisPhosphotase: F-1,6-bisP –> F6P (reverses PFK reaction).
3) Glucose-5-Phosphotase: G6P –> Glucose (reverses Hexokinase reaction).

Question 2

What is anaerobic metabolism?

Answer 2

aseif

Question 3

Homolactic Fermentation

Answer 3

Occurs in muscle tissue & some bacteria.
Catalyzed by Lactate Dehydrogenase (LDH).
Converts Pyruvate to Lactate, using NADH to make NAD+ in the process.

Question 4

Alcoholic Fermentation

Answer 4

Occurs in yeast.
Catalyzed by Pyruvate Decarboxylase & Alcohol Dehydrogenase.
Converts Pyruvate to CO2 + Ethanol, using NADH to make NAD+ in the process.