Edit · 3.3 Photosynthesis

What is photosynthesis?

Process whereby green plants make carbohydrates from carbon dioxide and water using light energy.

What are the two stages of photosynthesis?

Light reactions and carbon fixation.

What traps light energy from the sun in green plant cells?

Chlorophyll.

In what organelle is chlorophyll found?

Chloroplasts.

What is the energy change in photosynthesis?

Light to chemical energy.

What are the two reactions taking place in the light reactions?

Water to hydrogen plus oxygen through photolysis, and adp plus pi plus energy to atp through photophosphorylation.

What happens to the oxygen produced in photolysis?

It is released into the atmosphere.

What two products of the light reactions are required for carbon fixation?

Hydrogen and atp.

What controls the reactions of carbon fixation?

Enzymes.

What happens in carbon fixation?

Carbon dioxide combines with hydrogen using energy from atp from the light reactions to make glucose.

What are the three fates of glucose made by photosynthesis?

Used in respiration, used to make starch, and used to make cellulose.

What is the structural carbohydrate in plants?

Cellulose.

What is the storage carbohydrate in plants?

Starch.

What is a limiting factor?

A factor which when in short supply stops or slows down photosynthesis.

What are the three limiting factors for photosynthesis?

Temperature, light intensity, and carbon dioxide concentration.

What is the full word equation for photosynthesis?

Carbon dioxide + water -> glucose + oxygen (with light energy and chlorophyll above/below the arrow).

What happens to light energy at the start of Stage 1 (Light Dependent)?

Light energy is trapped by chlorophyll and converted into chemical energy, which is used to generate ATP.

What happens to water during Stage 1 (Light Dependent)?

Water is split into oxygen and hydrogen.

What happens to the oxygen and hydrogen produced in Stage 1?

Oxygen diffuses out of the leaf, while hydrogen and ATP move on to Stage 2 (Carbon Fixation).

What are the two raw materials that combine in Stage 2 (Carbon Fixation)?

Carbon dioxide and hydrogen.

What two things are required above and below the arrow in Stage 2 (Carbon Fixation)?

ATP (provides energy) and enzymes (control the series of reactions) to produce glucose.

What is the graph trend when light intensity or carbon dioxide concentration is the limiting factor?

Will level off when another factor becomes limiting.

What is the graph trend when temperature is the limiting factor?

It drops sharply because high temperatures denature the enzymes.