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Stomata

Small pores on the leaf surface that regulate gas exchange.

Chloroplast

Organelle in plant cells where photosynthesis occurs.

Thylakoids

Flattened sacs in chloroplasts where the light-dependent reactions occur.

Calvin Cycle

Light-independent reactions in photosynthesis that synthesize glucose from CO2.

Chlorophyll a

The primary pigment involved in photosynthesis, absorbing mainly red and blue light.

Photosystem

A complex of proteins and pigments in thylakoid membranes that initiates the light reactions.

Light-Dependent Reactions

The phase of photosynthesis that converts light energy into chemical energy (ATP, NADPH) and produces O2.

NADPH

An electron carrier produced in light reactions that provides reducing power in the Calvin cycle.

Electron Transport Chain

A series of protein complexes in the thylakoid membrane that transfer electrons and pump protons.

Photophosphorylation

The process of synthesizing ATP from ADP and inorganic phosphate using light energy.

3-PGA

Three-carbon compound formed in the first step of the Calvin cycle.

RuBisCO

Enzyme that catalyzes the reaction between CO2 and ribulose-1,5-bisphosphate in carbon fixation.

G3P

Glyceraldehyde-3-phosphate, a product of the Calvin cycle that can be used to form glucose.

C3 Plants

Plants that fix carbon directly into a three-carbon compound during photosynthesis.

C4 Plants

Plants that first fix CO2 into a four-carbon compound to increase efficiency under high light conditions.

CAM Plants

Plants that fix CO2 into organic acids at night to minimize water loss during the day.