• Definition: The range of a pigment’s ability to absorb various wavelengths of light.

• Term: Absorption Spectrum

2.

• Definition: Pigments that absorb light at different wavelengths than chlorophyll and pass the energy to chlorophyll for photosynthesis.

• Term: Accessory Pigment

3.

• Definition: Photosynthesis that does not produce oxygen, occurring in certain bacteria that use electron donors other than water.

• Term: Anoxygenic Photosynthesis

4.

• Definition: A complex of pigments that captures light energy and transfers it to the reaction center in photosynthesis.

• Term: Antenna Complex

5.

• Definition: An enzyme that creates ATP from ADP and inorganic phosphate during chemiosmosis in the mitochondria and chloroplasts.

• Term: ATP Synthase

6.

• Definition: Plants that use crassulacean acid metabolism (CAM) to fix carbon, adapted to dry environments by opening stomata at night to reduce water loss.

• Term: CAM Plants

7.

• Definition: The most common form of photosynthesis, where the Calvin cycle fixes carbon dioxide into a 3-carbon compound.

• Term: C3 Photosynthesis

8.

• Definition: Plants that use C3 photosynthesis, fixing carbon dioxide into a 3-carbon compound in the Calvin cycle.

• Term: C3 Plants

9.

• Definition: Plants that use a modified form of photosynthesis where carbon dioxide is initially fixed into a 4-carbon compound to minimize photorespiration.

• Term: C4 Plants

10.

• Definition: The cycle of reactions in photosynthesis that uses ATP and NADPH to convert CO₂ into sugars.

• Term: Calvin Cycle

11.

• Definition: The process of converting inorganic carbon (CO₂) into an organic form (sugar) during photosynthesis.

• Term: Carbon Fixation

12.

• Definition: Pigments that absorb excess light energy and protect chlorophyll from damage, such as β-carotene.

• Term: Carotenoids

13.

• Definition: The movement of an excited electron to a higher energy state in photosynthesis, initiating the electron transport chain.

• Term: Charge Separation

14.

• Definition: The movement of protons across a membrane to generate ATP, driven by the energy from the electron transport chain.

• Term: Chemiosmosis

15.

• Definition: The green pigment found in the chloroplasts of plants that captures light energy for photosynthesis.

• Term: Chlorophyll

16.

• Definition: The primary type of chlorophyll that absorbs light for photosynthesis, with absorption peaks in the violet-blue and red parts of the spectrum.

• Term: Chlorophyll a

17.

• Definition: An accessory pigment that helps chlorophyll a capture additional light energy by absorbing blue and red-orange light.

• Term: Chlorophyll b

18.

• Definition: A type of photosynthesis where the electron transport chain produces ATP but no NADPH or oxygen.

• Term: Cyclic Photophosphorylation

19.

• Definition: A protein complex in the thylakoid membrane that transfers electrons from plastoquinone to plastocyanin in photosynthesis.

• Term: Cytochrome b6-f Complex

20.

• Definition: The movement of electrons through a series of proteins and other molecules to produce energy in the form of ATP or NADPH.

• Term: Electron Transport

21.

• Definition: A protein that transfers electrons to NADP+ to form NADPH during the light reactions of photosynthesis.

• Term: Ferredoxin

22.

• Definition: The reactions of photosynthesis that require light, producing ATP and NADPH.

• Term: Light-Dependent Reactions

23.

• Definition: The reactions of photosynthesis that do not require light and use ATP and NADPH to convert CO₂ into sugars.

• Term: Light-Independent Reactions

24.

• Definition: A 3-carbon sugar formed in the Calvin cycle and used to synthesize glucose and other organic compounds.

• Term: Glyceraldehyde 3-Phosphate (G3P)

25.

• Definition: Stacks of thylakoids in the chloroplast where the light-dependent reactions of photosynthesis occur.

• Term: Grana

26.

• Definition: A coenzyme that carries electrons during the light reactions of photosynthesis, later reduced to form NADPH.

• Term: NADP+

27.

• Definition: An enzyme in the thylakoid membrane that reduces NADP+ to NADPH during the light-dependent reactions of photosynthesis.

• Term: NADP Reductase

28.

• Definition: The reduced form of NADP+, which carries electrons and is used in the Calvin cycle to help produce sugars.

• Term: NADPH

29.

• Definition: A process in photosynthesis where both ATP and NADPH are produced, and oxygen is released as a byproduct.

• Term: Non-Cyclic Photophosphorylation

30.

• Definition: Photosynthesis that produces oxygen as a byproduct, occurring in plants, algae, and cyanobacteria.

• Term: Oxygenic Photosynthesis

31.

• Definition: Molecules that absorb light at specific wavelengths and play a role in capturing energy for photosynthesis.

• Term: Pigments

32.

• Definition: A 3-carbon compound involved in the carbon fixation process in C4 and CAM plants.

• Term: Phosphoenolpyruvate (PEP)

33.

• Definition: A 3-carbon molecule formed in the Calvin cycle after CO₂ is fixed by rubisco.

• Term: 3-Phosphoglycerate (PGA)

34.

• Definition: The emission of electrons from a material when it absorbs light energy.

• Term: Photoelectric Effect

35.

• Definition: A particle of light energy that can excite electrons during the light-dependent reactions of photosynthesis.

• Term: Photon

36.

• Definition: A process where oxygen competes with carbon dioxide at rubisco, reducing the efficiency of photosynthesis.

• Term: Photorespiration

37.

• Definition: A photosystem that absorbs light energy, using it to produce NADPH in the light-dependent reactions.

• Term: Photosystem I

38.

• Definition: A photosystem that absorbs light energy, using it to split water and produce oxygen, ATP, and electrons.

• Term: Photosystem II

39.

• Definition: The process by which plants, algae, and some bacteria use light energy, CO₂, and water to produce glucose and oxygen.

• Term: Photosynthesis

40.

• Definition: Pigments in cyanobacteria and red algae that absorb light and pass the energy to chlorophyll for photosynthesis.

• Term: Phycobiliproteins

41.

• Definition: A copper-containing protein in the electron transport chain of photosynthesis that transfers electrons to photosystem I.

• Term: Plastocyanin

42.

• Definition: A molecule in the electron transport chain that transfers electrons from photosystem II to cytochrome b6-f complex.

• Term: Plastoquinone

43.

• Definition: A ring-shaped structure in chlorophyll that plays a central role in capturing light energy during photosynthesis.

• Term: Porphyrin Ring

44.

• Definition: The concentration difference of protons (H⁺ ions) across a membrane, which drives the synthesis of ATP.

• Term: Proton Gradient

45.

• Definition: The initial event in photosynthesis where a photon is absorbed, exciting an electron in a pigment molecule.

• Term: Primary Photoevent

46.

• Definition: The complex in a photosystem where energy from absorbed light is used to excite electrons, initiating electron transport.

• Term: Reaction Center

47.

• Definition: The gain of electrons by a molecule during a chemical reaction, often accompanied by the gain of energy.

• Term: Reduction