Valine Deamination and Oxidation

The video explains the catabolic pathway of leucine, highlighting its differences from valine catabolism. It details the enzymes involved, the mechanism of reactions, and the energy yield. The process includes electron transfer in mitochondria and biotin-dependent carboxylation, leading to the production of acetyl CoA and acetoacetate. The video concludes with a calculation of energy yield, emphasizing the importance of understanding this pathway.

What is the end product of leucine catabolism that is different from valine catabolism?

• Propionyl COA

• Succinyl COA

• Acetyl COA

• HMG COA

Which enzyme is involved in the initial transamination step of leucine catabolism?

• Lactate dehydrogenase

• Alpha ketoglutarate dehydrogenase

• Branch chain transaminase

• Pyruvate dehydrogenase

Which enzyme complex is mechanistically identical to the branch chain alpha ketoacid dehydrogenase complex?

• Malate dehydrogenase complex

• Citrate synthase complex

• Lactate dehydrogenase complex

• Pyruvate dehydrogenase complex

What is the role of electron transferring flavoprotein in leucine catabolism?

• It oxidizes NADH

• It transfers electrons to ubiquinone

• It generates ATP directly

• It acts as a proton pump

Which molecule is carboxylated in a biotin-dependent reaction during leucine catabolism?

• 3 methyl crotonyl CoA

• Succinyl COA

• Isovaleric scoa

• Acetoacetate

Which molecule acts as the carbon donor in the biotin-dependent carboxylation reaction?

• Methane

• Carbon monoxide

• Bicarbonate

• Carbon dioxide

What are the two products formed when HMG COA reacts with hydroxymethyl glutaryl CoA lyase?

• Propionyl COA and succinyl COA

• Acetyl COA and acetoacetate

• Acetoacetate and fumarate

• Acetyl COA and succinate

How many NADH molecules are produced in the complete catabolism of leucine?

• 9

• 10

• 11

• 12

What is the net yield of ATP from leucine catabolism?

• 2 ATP

• 4 ATP

• 1 ATP

• 3 ATP

What is the role of succinate in the TCA cycle during leucine catabolism?

• It is converted to oxaloacetate

• It is converted to fumarate

• It is converted to citrate

• It is converted to malate