Photosynthesis: Light-Dependent and Light-Independent Reactions

A collection of flashcards defining key terms and concepts related to the processes of photosynthesis, focusing on both light-dependent and light-independent reactions.

Light-Dependent Reactions

The first stage of photosynthesis that captures light energy and converts it into chemical energy in the form of ATP and NADPH.

Thylakoid Membrane

The site of the light-dependent reactions in the chloroplast, containing chlorophyll and stacked structures called grana.

Photolysis

The process of splitting water molecules using light energy during the light-dependent reactions.

Photosystem II (PS II)

The photosystem that absorbs light at 680 nm and is involved in the initial phase of the light-dependent reactions.

Photosystem I (PS I)

The photosystem that absorbs light at 700 nm and further energizes electrons during the light-dependent reactions.

NADP+

An electron acceptor that gets reduced to NADPH during the light-dependent reactions.

ATP Synthase

An enzyme that synthesizes ATP using the proton gradient established during the electron transport chain.

Calvin Cycle

The series of light-independent reactions in photosynthesis that utilize ATP and NADPH to convert CO2 into organic molecules.

Rubisco

An enzyme that catalyzes the first step of the Calvin cycle by fixing CO2 to ribulose bisphosphate (RuBP).

Chemiosmosis

The movement of H+ ions across a membrane, generating ATP as a result of the electrochemical gradient created during the light-dependent reactions.

Glyceraldehyde-3-Phosphate (G3P)

A 3-carbon molecule produced in the Calvin cycle, which can be used to form glucose.

Electron Transport Chain

A series of protein complexes that facilitate the transfer of electrons, leading to ATP production in the thylakoid membrane.

Hydrogen Ion Concentration Gradient

The difference in H+ ion concentration across the thylakoid membrane that drives ATP synthesis.

Reduction of NADP+

The process of converting NADP+ to NADPH during the light-dependent reactions, using excited electrons.

Photon

A particle of light that provides the energy necessary to excite electrons in photosystems.

ATP

A high-energy molecule produced during the light-dependent reactions, used for energy in various cellular processes.

Oxygen (O2)

A by-product of the photolysis of water during the light-dependent reactions.