Molecular oxygen is released during:
Correct answer: B. Light reaction in photosynthesis
- A. Calvin cycle
- B. Light reaction in photosynthesis
- C. Krebs cycle
- D. Glycolysis
Explanation
The light-dependent reactions of photosynthesis, also known as the light reactions, occur in the thylakoid membranes of chloroplasts and are responsible for the release of molecular oxygen. During these reactions, light energy is absorbed by chlorophyll, which drives the photolysis of water. This process splits water molecules into hydrogen ions, electrons, and oxygen atoms. The oxygen atoms then combine to form molecular oxygen (O2), which is released as a byproduct. This is the source of atmospheric oxygen replenishment.In contrast, the Calvin cycle (Option A) focuses on the fixation of carbon dioxide and does not produce oxygen. The Krebs cycle (Option C) and glycolysis (Option D) are part of cellular respiration, not photosynthesis, and do not release molecular oxygen.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Bioenergetics
Cellular respiration explains how cells release energy from glucose through glycolysis, the link reaction, Krebs cycle and electron transport chain. It includes ATP production, substrate-level and oxidative phosphorylation, aerobic versus anaerobic respiration, and the roles of mitochondria, oxygen and fermentation in energy transfer.
Practise Bioenergetics
1,378 free Bioenergetics MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Biology questions like this
Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.