NEW! Cytochrome c and Holocytochrome c Synthase: Biochemistry and Mechanism

The video explores the role and synthesis of cytochrome C, a soluble protein in the mitochondria that transfers electrons between complexes 3 and 4. It details the structure of cytochrome C, focusing on the heme C prosthetic group and the conserved amino acid sequence required for its binding. The enzymatic mechanism of attaching cysteine residues to heme B, transforming it into heme C, is explained. The video also discusses the oxidation states of iron and their significance in electron transfer, concluding with a look at nucleophilic addition reactions involved in the process.

What is the primary role of cytochrome C in the mitochondria?

• To store energy

• To break down glucose

• To transfer electrons from complex III to complex IV

• To synthesize ATP

What does the 'C' in cytochrome C signify?

• The presence of a copper ion

• The charge of the protein

• The type of heme group, specifically heme C

• The color of the protein

Which enzyme is responsible for attaching cysteine residues to heme B?

• Ubiquinol oxidoreductase

• Hollow cytochrome C synthase

• Cytochrome C oxidase

• ATP synthase

What is the initial oxidation state of iron in heme during synthesis?

• Neutral (0)

• Ferrous (2+)

• Ferric (3+)

• Ferryl (4+)

What is the role of molecular oxygen in the oxidation of iron in heme?

• It acts as an oxidizing agent

• It binds to the heme group

• It acts as a reducing agent

• It stabilizes the iron

What happens to cytochrome C after it donates an electron to cytochrome C oxidase?

• It becomes oxidized

• It becomes reduced

• It breaks down

• It forms a complex with ATP

Which complex does cytochrome C transfer electrons to after receiving them from complex III?

• Complex IV

• Complex I

• Complex V

• Complex II