Light Reaction - Labster Notes

Vocabulary-style flashcards covering the protein complexes, energy transfer mechanisms, and chemical equations of the photosynthetic light reaction.

Light reaction

The process by which sunlight is converted into chemical energy involving several protein complexes.

Photosystem I and II

Two separate photosynthesizing complexes in plants and algae containing specific pigment molecules that absorb different wavelengths of light.

Pigment molecules

Molecules that act as a funnel to absorb sunlight and transfer excitation energy to the reaction center.

Reaction center

A cluster of molecules that enable the conversion of excitation energy into an electron flow by propelling electrons out of chlorophyll molecules.

Plastoquinone

A carrier molecule in photosystem II that takes up two electrons and two protons to transfer electrons to the next complex in the electron transport chain.

Water-splitting process

The breakdown of water into molecular oxygen, protons, and electrons, where protons diffuse into the thylakoid lumen.

Molecular oxygen ($O_2$)

The waste product of photosynthesis produced at a ratio of one molecule for every two water molecules split.

Thylakoid lumen

The area where protons accumulate after being released during the splitting of water molecules.

Light reaction chemical equation

$$2 H_2O + 2 NADP^+ + nADP + nP_i \rightarrow O_2 + 2 NADPH + 2 H^+ + nATP$$

Chlorophyll molecules

Molecules within the reaction center from which electrons are propelled and subsequently absorbed by nearby molecules.