Refer to the Diagram Below, Showing Electron Transport and ATP

question 238

Multiple Choice

Refer to the diagram below, showing electron transport and ATP synthesis.When pure reduced cytochrome c is added to isolated mitochondria in a solution containing ADP, P_i, O₂, and antimycin A (a mitochondria complex II inhibitor) , the cytochrome c becomes oxidized and ATP is formed. Which sequence represents the probable flow of electrons in this system?

• A) NADH-Q reductase  cytochrome c  complex IV  O₂
• B) Cytochrome c  O₂  complex IV
• C) Complex IV  cytochrome c  O₂
• D) Cytochrome c  complex IV  O₂
• E) Cytochrome c  NADH-Q reductase  complex IV  O₂

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Definitions:

Thymine

A nitrogenous base found in DNA, pairing with adenine in the structure of the DNA molecule.

Cytosine

Cytosine is one of the four main bases found in DNA and RNA, pairing with guanine in the genetic code.

Guanine

One of the four main nucleobases found in the nucleic acids DNA and RNA, which pairs with cytosine.

Adenine

One of the four nucleobase molecules in the nucleic acids of DNA and RNA, paired with thymine in DNA and uracil in RNA.