Question

In which of the following site, water molecule broken down to release oxygen gas, electrons, and hydrogen ions?

• A. In the inner matrix of the mitochondria
• B. In the outer membrane of the chloroplast
• C. In the intermembrane space of the mitochondrion
• D. In the thylakoid space of the chloroplast
• E. In the intermembrane space of the chloroplast

Answer 1

Answer: (D)

In the thylakoid space of the chloroplast

Photosystem II has P680 reaction centre, in thylakoid space of chloroplast, wherein oxygen atoms of two water molecules bind to a cluster of manganese atoms. These Mn atoms, are bound to the reaction centre and associated with an enzyme that splits water, removes electrons one at a time. These electrons fill the holes, which are left in the reaction centre due to released to light-energized electrons. Immediately, after removal of four electrons from the two water molecules, O${}_2$ is released. Sunlight-driven splitting of water is called as photolysis. Mitochondria is the site for cellular respiration. So, the correct answer is option D.