The Light Dependent Reactions in Photosynthesis

Light Dependent Reactions

Produce ATP and NADPH for Calvin cycle.

Thylakoid

Membrane-bound compartments in chloroplasts.

Photosystem I

First photosystem in light reactions.

Photosystem II

Second photosystem in light reactions.

Chlorophyll

Pigment that absorbs light energy.

Electron Transport Chain

Series of proteins transferring electrons.

NADP+

Electron carrier that forms NADPH.

NADPH

High-energy electron carrier for Calvin cycle.

ATP Synthase

Enzyme that synthesizes ATP from ADP.

Stroma

Fluid surrounding thylakoids in chloroplasts.

Thylakoid Space

Interior space of thylakoids.

Water Splitting

Process generating oxygen and electrons.

Hydrogen Ions (H+)

Released during water splitting, used for ATP.

Oxygen

Byproduct of water splitting, released into atmosphere.

Light Energy

Energy absorbed by chlorophyll from sunlight.

Pigment Molecules

Chlorophyll and carotenoids in photosystems.

Electron Acceptor

Molecule that receives high-energy electrons.

Calvin Cycle

Light-independent reactions using ATP and NADPH.

Groma

Stacks of thylakoids in chloroplasts.

Excited Electrons

High-energy electrons from absorbed light.

ATP

Energy currency produced in light reactions.

Electron Transport

Movement of electrons through proteins.

Enzymes

Proteins that catalyze reactions in thylakoids.

Hydrogen Ion Concentration

Gradient used to produce ATP.