Thylakoids

Definition

Thylakoids are membrane-bound compartments inside chloroplasts and cyanobacteria. They are the site of the light-dependent reactions of photosynthesis where sunlight is converted into chemical energy.

5 Must Know Facts For Your Next Test

1. Thylakoids contain chlorophyll, the pigment that captures light energy.
2. They are organized into stacks called grana.
3. The space inside a thylakoid is known as the thylakoid lumen.
4. ATP synthesis happens in the thylakoid membrane during photosynthesis.
5. Thylakoids play a crucial role in converting solar energy into ATP and NADPH.

Review Questions

• What role do thylakoids play in photosynthesis?
• How are thylakoids arranged within the chloroplasts?
• What important molecules are found in the thylakoid membrane?

Related terms

Chloroplast:

Organelles in plant cells where photosynthesis occurs.

Grana:

Stacks of thylakoids within the chloroplast.

Chlorophyll:

Green pigment located in thylakoids that captures light energy for photosynthesis.