MDCAT Biology MCQ #455

MDCAT Biology MCQ #455

1. Question 1

   Q1. Comparing the electron transport chains of respiration and photosynthesis, what is the unique role of Cytochrome oxidase in mitochondria?

   • A) Cytochrome oxidase is the final carrier that reduces oxygen
   • B) Cytochrome b-f is found in the inner mitochondrial membrane
   • C) Cytochrome oxidase pumps protons into the thylakoid lumen
   • D) Cytochrome b-f reduces NADP+ directly to form NADPH

   Answer: Cytochrome oxidase is the final carrier that reduces oxygen

   Explanation: Cytochrome b-f is part of the photosynthetic ETC, while Cytochrome oxidase (a3) is the final carrier in respiratory ETC.