Biology 8.3

The Reactions of Photosynthesis 8.3

Thylakoid

• Saclike photosynthetic membrane found in chloroplasts.

Photosystem

• Light-collecting units of the chloroplast.

Stroma

• Region outside the thylakoid membranes in the chloroplasts.

NADP+

• One of the carrier molecules that transfers high-energy electrons from chlorophyll to other molecules.

Light-Dependent Reactions

• Reactions of photosynthesis that use energy from light to produce ATP and NADPH.

ATP Synthase • Large protein that uses energy from H+

ions to bind ADP and a phosphate group together to produce ATP.

Calvin Cycle • Reactions of photosynthesis in which

energy from ATP and NADPH is used to build high-energy compounds such as sugars.

Key Concept

• What happens in the light-dependent reactions?–The light-dependent reactions produce

oxygen gas and convert ADP and NADP+ into the energy carriers ATP and NADPH.

Key Concept

• What is the Calvin cycle?–Reactions of photosynthesis in which

energy from ATP and NADPH is used to build high-energy compounds such as sugars.