Granum

Definition

A granum is a stack of thylakoid membranes found within the chloroplasts of plant cells. It plays a crucial role in the light-dependent reactions of photosynthesis by capturing and converting light energy into chemical energy.

5 Must Know Facts For Your Next Test

1. Grana are interconnected by lamellae, also known as stroma thylakoids.
2. Each granum can contain anywhere from a few to around 50 thylakoids stacked together.
3. The thylakoid membranes within grana contain chlorophyll, which is essential for absorbing light energy.
4. The arrangement of thylakoids in grana increases the surface area for light absorption.
5. ATP and NADPH, which are produced during the light-dependent reactions in the grana, are used in the Calvin cycle.

Review Questions

Related terms

Thylakoid:

A membrane-bound compartment inside chloroplasts where light-dependent reactions take place.

Chloroplast:

An organelle found in plant cells that conducts photosynthesis.

Stroma: The fluid-filled space surrounding grana where the Calvin cycle takes place.