The Light Reactions of Photosynthesis

These flashcards cover key vocabulary terms and concepts related to the light reactions of photosynthesis, including structures, processes, and functions.

Photosynthesis

The process that converts solar energy into ATP and NADPH, powering almost all life.

Light reactions

The part of photosynthesis where photons are captured and converted into chemical energy (ATP and NADPH).

Chloroplasts

Organelles where photosynthesis takes place, specifically containing thylakoid membranes involved in light reactions.

Electron transport chain

Process where electrons are transferred through protein complexes, facilitating the production of ATP and NADPH.

Z-scheme

The pathway of electron flow in the light reactions, involving two photosystems (PSII and PSI).

Chemiosmosis

Process that generates ATP using a proton gradient created by the light reactions.

P680

The special pair of chlorophyll molecules in Photosystem II that absorb light at 680 nm.

P700

The special pair of chlorophyll molecules in Photosystem I that absorb light at 700 nm.

Fluorescence

The light emitted when an excited electron returns to its original state, often released as energy.

Photolysis

The process of splitting water molecules to generate oxygen during photosynthesis.

Ferredoxin

A small iron-sulfur protein that acts as an electron carrier in photosynthesis.

NADPH

An electron carrier and reducing power formed during the light reactions, used in the Calvin cycle.

Antenna complex

Group of pigments that capture light and transfer energy to the reaction center, enhancing light absorption.

Charge separation

The creation of charged species (D+ and A-) at the reaction center of photosystems upon electron transfer.

Nonphotochemical quenching (NPQ)

A protective mechanism in plants where excess energy from light is dissipated as heat to prevent damage.

Mn4CaO5 cluster

The complex in PSII that enables the oxidation of water, essential for oxygen production in photosynthesis.