Term: Absorption spectrum
Definition: The range of wavelengths of light absorbed by a pigment, such as chlorophyll, during photosynthesis.

Term: Accessory pigment
Definition: A pigment that assists in photosynthesis by capturing additional light wavelengths that chlorophyll cannot absorb.

Term: Anoxygenic photosynthesis
Definition: A form of photosynthesis that does not produce oxygen, typically found in certain bacteria.

Term: Antenna complex
Definition: A collection of pigment molecules that gather photons and pass the energy to the reaction center in a photosystem.

Term: ATP Synthase
Definition: An enzyme in the thylakoid membrane that produces ATP from ADP and inorganic phosphate using the proton gradient.

Term: CAM plants
Definition: Plants that fix carbon at night using crassulacean acid metabolism, minimizing water loss by opening stomata at night.

Term: C3 photosynthesis
Definition: The most common form of photosynthesis, where CO2 is initially fixed into a three-carbon compound.

Term: C3 plants
Definition: Plants that use the C3 pathway for carbon fixation, which is most efficient under cool, moist conditions.

Term: C4 plants
Definition: Plants that fix CO2 into a four-carbon compound as part of a process that reduces photorespiration, typically adapted to hot, dry environments.

Term: Calvin cycle
Definition: The cycle of reactions that take place in the stroma of chloroplasts during photosynthesis, where carbon fixation occurs and glucose is produced.

Term: Carbon fixation
Definition: The process of converting inorganic carbon (CO2) into an organic form (glucose) during photosynthesis.

Term: Carotenoids
Definition: Accessory pigments that absorb blue and green light and reflect yellow, orange, or red, aiding in photosynthesis.

Term: Charge separation
Definition: The process in photosynthesis where excited electrons are transferred from the reaction center to an acceptor molecule.

Term: Chemiosmosis
Definition: The process by which the movement of protons across a membrane drives the production of ATP.

Term: Chlorophyll
Definition: The green pigment that captures light energy for photosynthesis.

Term: Chlorophyll a
Definition: The primary pigment in photosynthesis that absorbs light mainly in the blue and red wavelengths.

Term: Chlorophyll b
Definition: An accessory pigment that broadens the range of light a plant can use for photosynthesis by absorbing light in the blue and orange wavelengths.

Term: Cyclic photophosphorylation
Definition: A process in photosynthesis where electrons are cycled back to the photosystem, generating ATP without producing NADPH or oxygen.

Term: Cytochrome b6-f complex
Definition: A component of the electron transport chain in the thylakoid membrane that pumps protons across the membrane to create a proton gradient.

Term: Electron transport
Definition: The movement of electrons through a series of protein complexes in the thylakoid membrane to create an electrochemical gradient.

Term: Ferredoxin
Definition: An iron-sulfur protein that acts as an electron carrier in photosynthesis, transferring electrons to NADP+ reductase.

Term: Light-dependent reactions
Definition: The set of reactions in photosynthesis that convert light energy into chemical energy in the form of ATP and NADPH.

Term: Light-independent reactions
Definition: Reactions that do not require light, such as the Calvin cycle, where ATP and NADPH produced in the light-dependent reactions are used to fix carbon into sugars.

Term: Glyceraldehyde 3-phosphate (G3P)
Definition: A three-carbon sugar produced in the Calvin cycle that can be used to form glucose and other carbohydrates.

Term: Grana
Definition: Stacks of thylakoid membranes within the chloroplasts where light-dependent reactions of photosynthesis take place.

Term: NADP+
Definition: An electron carrier that is reduced to NADPH during the light-dependent reactions of photosynthesis.

Term: NADP reductase
Definition: The enzyme that catalyzes the transfer of electrons from ferredoxin to NADP+, forming NADPH.

Term: NADPH
Definition: The reduced form of NADP+ that carries electrons and hydrogen ions for use in the Calvin cycle during photosynthesis.

Term: Non-cyclic photophosphorylation
Definition: The process in photosynthesis where electrons move linearly through the electron transport chain, resulting in the production of both ATP and NADPH.

Term: Oxygenic photosynthesis
Definition: Photosynthesis that produces oxygen, as seen in plants, algae, and cyanobacteria.

Term: Pigments
Definition: Molecules that absorb certain wavelengths of light and reflect others, used by plants to capture light energy for photosynthesis.

Term: Phosphoenolpyruvate (PEP)
Definition: A three-carbon molecule involved in the C4 photosynthetic pathway as an intermediate for carbon fixation.

Term: 3-phosphoglycerate (PGA)
Definition: A three-carbon compound formed in the Calvin cycle during the fixation of CO2.

Term: Photoelectric effect
Definition: The process by which light energy excites electrons, causing them to move to a higher energy state.

Term: Photon
Definition: A particle of light that carries energy, which can excite electrons in pigments during photosynthesis.

Term: Photorespiration
Definition: A wasteful process in plants where oxygen is fixed instead of carbon dioxide by rubisco, reducing the efficiency of photosynthesis.

Term: Photosystem I
Definition: The second photosystem in the electron transport chain of photosynthesis that absorbs light to excite electrons for NADPH production.

Term: Photosystem II
Definition: The first photosystem in the electron transport chain of photosynthesis that absorbs light, initiating the electron transport chain and splitting water molecules.

Term: Photosynthesis
Definition: The process by which plants, algae, and some bacteria convert light energy, water, and carbon dioxide into glucose and oxygen.

Term: Phycobiliproteins
Definition: Accessory pigments found in cyanobacteria and red algae that help capture light energy for photosynthesis.

Term: Plastocyanin
Definition: A copper-containing protein that transfers electrons between the cytochrome b6-f complex and photosystem I.

Term: Plastoquinone
Definition: An electron carrier in the thylakoid membrane that transfers electrons between photosystem II and the cytochrome b6-f complex.

Term: Porphyrin ring
Definition: The light-absorbing part of the chlorophyll molecule, responsible for capturing light energy during photosynthesis.

Term: Proton gradient
Definition: A difference in proton concentration across a membrane, which powers ATP synthesis during photosynthesis.

Term: Primary photoevent
Definition: The initial absorption of light by pigments in photosystems, resulting in the excitation of electrons.

Term: Reaction center
Definition: A complex of proteins and pigments where charge separation occurs, triggering the electron transport chain in photosynthesis.

Term: Reduction
Definition: A chemical reaction where a molecule gains electrons, often associated with energy gain.

Term: Regeneration of RuBP
Definition: The final stage of the Calvin cycle where RuBP is regenerated, allowing the cycle to continue.

Term: Ribulose 1,5-bisphosphate (RuBP)
Definition: A five-carbon compound that combines with CO2 in the Calvin cycle to form 3-phosphoglycerate.

Term: Rubisco
Definition: Ribulose bisphosphate carboxylase/oxygenase; the enzyme that catalyzes the first step of carbon fixation in the Calvin cycle.

Term: Stomata
Definition: Small openings on the surface of leaves that allow gas exchange, including the intake of CO2 for photosynthesis.

Term: Stroma
Definition: The fluid-filled space in chloroplasts surrounding the thylakoid membranes where the Calvin cycle takes place.

Term: Thylakoid membrane
Definition: The internal membrane in chloroplasts that contains the components for the light-dependent reactions of photosynthesis.