Pyruvate Dehydrogenase Complex

Flashcards covering key concepts related to the pyruvate dehydrogenase complex, its regulation, cofactors, and associated metabolic functions.

What is the function of the pyruvate dehydrogenase complex (PDC)?

The PDC oxidizes pyruvate to Acetyl-CoA under aerobic conditions.

What are the cofactors required for the pyruvate dehydrogenase complex?

Thiamin (thiamin diphosphate), lipoamide, FAD, and NAD.

How is the pyruvate dehydrogenase complex regulated allosterically?

It can be activated by NAD+ and pyruvate, and inhibited by Acetyl-CoA and NADH.

What effect does high NADH have on the pyruvate dehydrogenase complex?

High NADH signals sufficient energy levels, leading to decreased activity of the PDC.

Which enzyme phosphorylates the pyruvate dehydrogenase complex?

Pyruvate dehydrogenase with kinase.

When is the pyruvate dehydrogenase kinase most active?

When Acetyl-CoA, NADH, and ATP levels are high.

What role do insulin and calcium play in the regulation of the pyruvate dehydrogenase complex?

High levels of insulin and calcium activate a phosphatase that dephosphorylates and activates the enzyme.

What cofactor deficiency would decrease the activity of the pyruvate dehydrogenase complex?

Thiamin deficiency would result in decreased activity.

What is biotin required for in metabolism?

Biotin is required for carboxylation reactions, specifically by pyruvate carboxylase or Acetyl-CoA carboxylase.

What is the function of folate in metabolism?

Folate is required for nucleotide synthesis.