A cluster of what kind of ions is responsible for passing electrons one-at-a-time to the nearby P680⁺ in the reaction center? A)a cluster of 5 iron ions B)a cluster of 4 manganese ions and one calcium ion C)a cluster of one magnesium ion and 4 calcium ions D)a cluster of 5 copper ions E)a cluster of 5 manganese ions

Question

Quizplus · Accepted Answer

The cluster responsible for passing electrons one-at-a-time to the nearby P680⁺ in the reaction center is a cluster of 4 manganese ions and one calcium ion, known as the oxygen-evolving complex (OEC). This cluster plays a critical role in the light-dependent reactions of photosynthesis, facilitating the transfer of electrons from water to photosystem II (PSII) and ultimately to photosystem I (PSI) for the generation of ATP and NADPH. The OEC undergoes a series of four oxidation-reduction reactions, each of which involves the transfer of four electrons and the evolution of one molecule of oxygen. In this way, the OEC serves as the source of molecular oxygen in the atmosphere, which is essential for most forms of life on Earth.

A Cluster of What Kind of Ions Is Responsible for Passing