Photosynthesis Basic
Pigments and Light Energy
Photosystems and Light Reactions
The Calvin Cycle
Photorespiration and Plant Types
100

Where does photosynthesis mainly occur in plants?

In the leaves, specifically in chloroplasts.

100

What is a photon?

A particle of light that acts as a bundle of energy.

100

What are the two main parts of a photosystem?

The antenna complex and the reaction center.

100

Where does the Calvin cycle take place?

In the stroma of the chloroplast.

100

What are the two activities of Rubisco?

Carboxylation (adds CO₂) and oxygenation (adds O₂).

200

Which organisms carry out oxygenic photosynthesis?

Cyanobacteria, algae, and land plants.

200

What happens to photon energy as wavelength decreases?

Energy increases.

200

What happens in the antenna complex?

Light is absorbed and transferred to the reaction center.

200

What enzyme catalyzes CO₂ fixation?

Rubisco (RuBP carboxylase/oxygenase).

200

Why is photorespiration inefficient?

It uses ATP and NADPH without producing glucose.

300

What gas do plants release during photosynthesis?

Oxygen

300

What are the two main pigment types in plants?

Chlorophylls and carotenoids.

300

What occurs during the primary photo event?

A photon excites an electron in a pigment molecule.

300

What are the three phases of the Calvin cycle?

Carbon fixation, reduction, regeneration of RuBP.

300

How do C3 and C4 plants differ?

C4 plants use PEP carboxylase and separate carbon fixation spatially.

400

Which gas do plants take in for photosynthesis?

Carbon dioxide (CO₂).

400

What is the main role of chlorophyll a?

Converts light energy to chemical energy.

400

What are the final products of noncyclic photophosphorylation?

ATP, NADPH, and O₂.

400

How many turns are needed to make one glucose molecule?

Six turns.

400

When do CAM plants fix CO₂?

At night, storing it as organic acids for daytime use.

500

What are the two main stages of photosynthesis?

The light-dependent reactions and the Calvin cycle (light-independent reactions).

500

Why are carotenoids important besides absorbing light?

They act as antioxidants, protecting from reactive oxygen species.

500

Which photosystem is used in cyclic photophosphorylation?

Photosystem I only.

500

What are the main inputs for the Calvin cycle?

ATP, NADPH, and CO₂.

500

How do C4 and CAM plants reduce photorespiration?

By increasing CO₂ near Rubisco — C4 spatially, CAM temporally.