Reduction

Definition

Reduction is the gain of electrons by an atom, molecule, or ion. In biological systems, it often involves the addition of hydrogen atoms or the removal of oxygen atoms.

5 Must Know Facts For Your Next Test

1. Reduction reactions are crucial in converting light energy into chemical energy during the process of photosynthesis.
2. In photosynthesis, carbon dioxide is reduced to form glucose.
3. The Calvin cycle includes several reduction steps where NADPH donates electrons.
4. Reduction and oxidation reactions (redox reactions) are coupled; when one substance is reduced, another is oxidized.
5. ATP and NADPH produced in the light-dependent reactions provide the energy and electrons needed for the reduction steps in the Calvin cycle.

Review Questions

• What role does reduction play in the Calvin cycle?
• How are ATP and NADPH involved in reduction during photosynthesis?
• Why must reduction and oxidation reactions be coupled in biological systems?

Related terms

Oxidation:

The loss of electrons by an atom, molecule, or ion.

NADPH:

A coenzyme that carries electrons and provides reducing power for biosynthetic reactions.

Calvin Cycle: The set of chemical reactions that take place in chloroplasts during photosynthesis to convert carbon dioxide into glucose.