Photosynthesis: Light Reactions

Front

What is photosynthesis?

Back

Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose, using carbon dioxide and water.

Front

What are the two main stages of photosynthesis?

Back

The two main stages of photosynthesis are the light reactions and the Calvin cycle (light-independent reactions).

Front

Where do the light reactions of photosynthesis occur?

Back

The light reactions occur in the thylakoid membranes of the chloroplasts.

Front

What is the role of chlorophyll in photosynthesis?

Back

Chlorophyll is a pigment that absorbs light energy, primarily from the sun, which is essential for the light reactions of photosynthesis.

Front

What is photolysis?

Back

Photolysis is the process of splitting water molecules into oxygen, protons, and electrons using light energy during the light reactions of photosynthesis.

Front

What is the main product of the light reactions?

Back

The main products of the light reactions are ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate), which are used in the Calvin cycle.

Front

What is the function of Photosystem II?

Back

Photosystem II captures light energy and uses it to split water molecules, releasing oxygen and providing electrons for the electron transport chain.

Front

What is the function of Photosystem I?

Back

Photosystem I captures light energy to produce NADPH from NADP+ and electrons.

Front

How does light intensity affect the rate of photosynthesis?

Back

As light intensity increases, the rate of photosynthesis generally increases until it reaches a saturation point.

Front

What role does carbon dioxide play in photosynthesis?

Back

Carbon dioxide is a reactant in the Calvin cycle, where it is fixed into glucose.