AP Biology photosynthesis details study guide

What is photosynthesis?

Process by which plants, algae, and some bacteria convert light energy into chemical energy.

Formula for photosynthesis

6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂.

Location of photosynthesis in plants

Occurs mainly in chloroplasts of leaf cells.

True or False: Light reactions occur in the stroma.

False, because light reactions occur in the thylakoid membranes.

What are chlorophylls?

Pigments in chloroplasts that absorb light, primarily blue-violet and red light.

Difference between light-dependent and light-independent reactions

Light-dependent: require light, produce ATP and NADPH. Light-independent: do not require light, use ATP and NADPH to synthesize glucose.

What is the Calvin Cycle?

Series of biochemical reactions during photosynthesis that convert CO₂ into glucose using ATP and NADPH.

What is carbon fixation?

The process of converting inorganic CO₂ into organic compounds during photosynthesis.

Fill in the blank: The main product of the light-independent reactions is _____

glucose.

True or False: Oxygen is produced during the Calvin Cycle.

False, because oxygen is produced during the light-dependent reactions.

What role do electron transport chains play?

They transfer electrons from photosystem II to photosystem I, facilitating ATP synthesis.

What is photolysis?

The process of breaking down water molecules into oxygen, protons, and electrons using light energy.

Difference between cyclic and non-cyclic photophosphorylation

Cyclic: produces ATP only. Non-cyclic: produces ATP and NADPH.

What is the significance of RuBisCO?

An enzyme that catalyzes the first step of carbon fixation in the Calvin Cycle.

What are the products of light-dependent reactions?

ATP, NADPH, and O₂.

Fill in the blank: The thylakoids are located in the _____ of chloroplasts.

stroma.

Which pigments absorb light energy?

Chlorophyll a, chlorophyll b, and carotenoids.

True or False: Photosynthesis occurs in all plant types.

False, because some plants are heterotrophic and do not perform photosynthesis.

What is the role of NADP+?

It acts as an electron carrier, becoming NADPH during light reactions.

Difference between C3 and C4 plants

C3: use Calvin Cycle directly. C4: modify carbon fixation to minimize photorespiration.

What is photorespiration?

A process where RuBisCO binds O₂ instead of CO₂, reducing photosynthetic efficiency.

Which part of the plant is primarily responsible for photosynthesis?

Leaves, due to high chloroplast concentration.

Fill in the blank: The main energy carrier in photosynthesis is _____

ATP.

What are stomata?

Tiny openings on leaf surfaces that allow gas exchange for photosynthesis.

What is the role of water in photosynthesis?

Source of electrons and protons; oxygen is released as a byproduct.