Question

Three cellular processes are listed. Choose the correct combination of processes that involves proton gradient across the membrane.
i) Photosynthesis
ii) Aerobic respiration
iii) Anaerobic respiration

• A. ii) and iii)
• B. i) and ii)
• C. i), ii) and iii)
• D. i) and iii)

Answer 1

Answer: (B)

i) and ii)

Processes like photosynthesis and aerobic respiration involves proton gradient across the membrane. The process of photosynthetic electron transfer generates a proton gradient across the photosynthetic membrane. A higher concentration of protons outside the inner membrane of the mitochondria than inside is the driving force behind ATP synthesis. The ETC uses ATP as the energy to pump hydrogen ions across a membrane. This stored energy in the proton gradient is used for the active transport of several molecules and ions through the inner mitochondrial membrane into the matrix.

Thus, the correct answer is option B.