biochemistry exam 3 side quest electron transport

Electron Transport and Oxidative Phosphorylation

What important energy molecule is created from the gradient set up by the electron transport chain?

ATP

What is the role of FADH₂ in the electron transport chain?

reactant

intermediate

product

reactant

Where do NADH and FADH₂ get the electrons that they bring to the electron transport chain?

TCA cycle

How many protons total are pumped into the intermembrane space for each pair of electrons originally derived from NADH?

6

Which protein has a greater affinity for electrons, cytochrome a or cytochrome c?

cytochrome a

cytochrome c

Both proteins have the same electron affinity.

cytochrome a

What species accepts electrons in the final step of the electron transport chain?

Enter a chemical name, not a chemical formula.

oxygen

What is the role of water in the electron transport chain?

reactant

intermediate

product

product

The translocation of protons across the inner membrane of the mitochondria sets up chemical, electrical and pH gradients. Which compartment has a lower pH?

matrix

intermembrane space

intermembrane space

The electron transport chain is a complex, membrane-bound system that transports electrons from NADH or FADH₂ to O₂. This system is usually tightly coupled to the production of ATP through oxidative phosphorylation.According to the proposed model, how many protons are transported from the matrix to the intermembrane space?

one

two

three

four

four - The net effect of reducing NADH and generating UQH₂ is the transportation of four protons from the inside of the matrix to the outside of the matrix.

The electron transport chain is a complex, membrane-bound system that transports electrons from NADH or FADH₂ to O₂. This system is usually tightly coupled to the production of ATP through oxidative phosphorylation. How many separate oxidations occur in going from NADH to UQH₂ in the membrane?

three

four

five

six

five - NADH, FMNH₂, and Fe²⁺ are oxidized in the first Fe-S center, and UQH₂ and Fe²⁺ are oxidized in the second Fe-S center.

How many electrons are released from UQH₂ during the process?

one

two

three

four

four

How many electrons go into reducing cyt c?

one

two

three

four

two

What happens to the other two electrons?

They are dissipated as heat.

They reduce a molecule of UQ.

They interact with the phospholipids.

They reduce a molecule of UQ.

At what stage in the transfer of electrons does the reduction of O₂ to H₂O take place? (Cytochrome c oxidase is also called Complex IV)

Cyt c to Cu_A

Cu_A to cyt a

Cyt a to cyt a₃

Cyt a₃ to Cu_B

Cyt a₃ to Cu_B

At what stage is the transport of protons from the matrix to the intermembrane space coupled to the transfer of electrons? (Cytochrome c oxidase is also called Complex IV)

Cyt c to Cu_A

Cu_A to cyt a

Cyt a to cyt a3

Cyt a₃ to Cu_B

Cyt a to cyt a3

Which component of this system (Cytochrome c oxidase is also called Complex IV)is mobile?

Cyt c

Cyt a

Cyt a₃

Cyt c