CARBOHYDRATE METABOLISM PART 1

Where does glycolysis occur?

cytoplasm of all cells

What does glycolysis not require?

oxygen

What does glycolysis yield?

2 ATP per glucose

important enzymes in glycolysis include:

-glucokinase

-hexokinase

-phosphofructokinase-1 (PFK-1)

-phosphofructokinase-2 (PFK-2)

-glyceraldehyde-3-phosphate dehydrogenase

-3-phosphoglycerate kinase and pyruvate kinase

Glucokinase

present in liver and pancreatic beta cells, responsive to insulin; phosphorylates glucose

Hexokinase

present in all tissue; phosphorylates glucose to trap it in cells

Phosphofructokinase-1 (PFK-1)

rate limiting step

Phosphofructokinase-2 (PFK-2)

produces F2,6-BP, which activates PFK-1

Glyceraldehyde-3-phosphate dehydrogenase

produces NADH

3-phosphoglycerate kinase and pyruvate kinase

perform substrate-level phosphorylation

What catalyzes irreversible reactions in glycolysis?

-glucokinase

-hexokinase

-PFK-1

-pyruvate kinase

NADH production in glycolysis is oxidized aerobically by

mitochondrial electron transport chain

NADH production in glycolysis is oxidized anaerobically by

cytoplasmic lactate dehydrogenase

Pyruvate Dehydrogenase

converts pyruvate to acetyl-CoA

Pyruvate Dehydrogenase stimulated by

insulin

Pyruvate Dehydrogenase inhibited by

acetyl-CoA