Photosynthesis: Light-Dependent and Light-Independent Reactions

Photosynthesis

Process converting light energy into chemical energy.

Light-Independent Reactions

Synthesis phase of photosynthesis, no light required.

Light-Dependent Reactions

Phase requiring visible light to produce ATP and NADPH.

Cellular Respiration Equation

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy.

Photosynthesis Equation

Energy + 6 CO2 + 6 H2O → C6H12O6 + 6 O2.

Catabolic Reaction

Exergonic process releasing energy for ATP generation.

Anabolic Reaction

Endergonic process requiring energy input for synthesis.

Calvin Cycle

Converts CO2 into carbohydrates using ATP and NADPH.

Glyceraldehyde 3-Phosphate (G3P)

Final product of Calvin Cycle, not glucose.

Carbon Fixation

Attaching inorganic carbon to an organic molecule.

Rubisco

Enzyme facilitating carbon fixation in the Calvin Cycle.

Reduction Phase

Addition of electrons and protons to form carbohydrates.

Regeneration Phase

Converts G3P back into RuBP using ATP.

ATP Consumption

9 ATPs consumed to build one G3P molecule.

NADPH Consumption

6 NADPHs consumed during Calvin Cycle.

Photosynthetic Pigments

Chemicals absorbing light, located in thylakoid membranes.

Chlorophyll

Primary pigment linking sunlight to photosynthesis.

Carotenoids

Pigments providing yellow and orange colors in plants.

Photosystems

Membrane complexes organizing pigments for light absorption.

P680 and P700

Chlorophyll types in PS II and PS I, respectively.

Water-Splitting Complex

Replaces lost electrons in P680 by oxidizing water.

Chemiosmosis

Process generating ATP using a proton gradient.

Photophosphorylation

Light-driven phosphorylation of ADP to ATP.

Oxygen By-Product

O2 released during light-dependent reactions.

NADP+ Reduction

Process of converting NADP+ to NADPH in stroma.

Excitation of PS I

Energizes electrons to reduce NADP+.

Starch Synthesis

G3P used to form glucose polymer for energy storage.

Sucrose Synthesis

G3P precursor for disaccharide transport sugar.