Understanding the Process of Photosynthesis

Photosynthesis

Process converting sunlight into glucose and oxygen.

Glucose

Simple sugar produced during photosynthesis.

Pyruvate

Intermediate product in cellular respiration from glucose.

ATP

Energy currency of the cell, produced during respiration.

Chlorophyll

Green pigment essential for photosynthesis in plants.

Accessory pigments

Molecules aiding chlorophyll in light absorption.

Chlorophyll a

Primary pigment absorbing violet-blue and red light.

Chlorophyll b

Accessory pigment that complements chlorophyll a.

Xanthophylls

Yellow pigments that assist in photosynthesis.

Carotenoids

Pigments like beta-carotene aiding light absorption.

Stomata

Small openings on leaves for gas exchange.

Guard cells

Cells regulating the opening and closing of stomata.

Xylem vessels

Specialized cells transporting water to leaves.

Cuticle

Waxy layer protecting leaves from water loss.

Thylakoid

Flattened sac where photosynthesis occurs in chloroplasts.

Grana

Stacks of thylakoids in chloroplasts.

Stroma

Fluid surrounding thylakoids in chloroplasts.

Photoactivation

Process of chlorophyll absorbing light energy.

Primary electron acceptor

Molecule receiving excited electrons from chlorophyll.

NADP

Molecule that carries electrons in photosynthesis.

Water splitting

Process producing oxygen during photosynthesis.

Carbon dioxide

Gas absorbed by plants for photosynthesis.

Oxygen

Byproduct released during photosynthesis.

Condensation Reactions

Reactions that release water molecules during bonding.

Phosphorylation

Addition of a phosphate group to an organic compound.

Redox Reactions

Reactions involving electron transfer between molecules.

Light-Dependent Reactions

Reactions requiring light energy to produce ATP.

Grana

Stacked thylakoid membranes in chloroplasts.

Photophosphorylation

Light energy used to generate ATP.

Photolysis

Splitting of water into oxygen and electrons.

NADP+

Oxidized form of nicotinamide adenine dinucleotide phosphate.

NADPH

Reduced form of nicotinamide adenine dinucleotide phosphate.

Light-Independent Reactions

Reactions using ATP and NADPH to synthesize carbohydrates.

Glyceraldehyde 3-Phosphate

A 3-carbon molecule formed during carbohydrate synthesis.

Photoexcitation

Absorption of light energy by chlorophyll electrons.

Photoionisation

Process of freeing an electron from chlorophyll.

Photosystem II (PSII)

First photosystem in the light-dependent reactions.

Photosystem I (PSI)

Second photosystem in the light-dependent reactions.

Z Scheme

Electron transfer process visualized as a Z shape.

Electron Transport Chain

Series of reactions transferring electrons to produce energy.

Chemiosmosis

Process of ATP synthesis driven by ion gradients.

Thylakoid Membrane

Membrane where light-dependent reactions occur.

ADP

Adenosine diphosphate, precursor to ATP.

ATP

Adenosine triphosphate, energy carrier molecule.

Electron Acceptor

Molecule that receives electrons during electron transfer.

Electron Donor

Molecule that donates electrons during reactions.

Electrons

Charged particles providing energy in photosynthesis.

Transport chain

Series of proteins transferring electrons in chloroplasts.

H+ ions

Protons pumped across thylakoid membrane, creating gradient.

Electrochemical gradient

Difference in ion concentration across a membrane.

Chemiosmosis

Process using ion gradients to synthesize ATP.

Photophosphorylation

ATP production linked to light energy absorption.

Cyclic phosphorylation

ATP generation without NADPH formation in photosynthesis.

Photosystem I

Light-absorbing complex generating excited electrons.

NADP+

Electron carrier reduced to NADPH in photosynthesis.

Light-independent reactions

Carbon fixation process occurring without light.

Carbon fixation

Incorporation of CO2 into organic compounds.

Ribulose 1,5-bisphosphate (RuBP)

Five-carbon sugar combining with CO2 in Calvin cycle.

Glycerate 3-phosphate (GP)

Three-carbon compound formed from RuBP breakdown.

Glyceraldehyde 3-phosphate (GALP)

Product of GP reduction, used in glucose synthesis.

Calvin cycle

Series of reactions converting CO2 to carbohydrates.

Phosphoglycerate (PGA)

First stable product of the Calvin cycle.

RuBP regeneration

Process reforming RuBP from GALP in Calvin cycle.

Limiting factors

Conditions affecting the rate of photosynthesis.

Light intensity

Amount of light affecting photosynthesis rate.

Optimal temperature

Temperature range maximizing enzyme activity in photosynthesis.

Chlorophyll a

Pigment used in both photosystems for light absorption.

Wavelength absorption

Specific light wavelengths absorbed by PSI and PSII.

Glycolysis

Metabolic pathway releasing energy from glucose.