Flashcards on Photosynthesis and Chloroplasts

These flashcards cover key terms and concepts related to photosynthesis and chloroplasts to aid in exam preparation.

Chloroplast

An organelle in plant cells that conducts photosynthesis by absorbing sunlight and converting it into chemical energy.

Stroma

The dense fluid within the chloroplast that surrounds the thylakoids and is involved in the Calvin cycle.

Thylakoid

A membrane-bound compartment inside chloroplasts where the light-dependent reactions of photosynthesis occur.

Granum (Grana)

A stack of thylakoids within a chloroplast that increases the surface area for light absorption in photosynthesis.

Photoautotrophs

Organisms like plants and some bacteria that use light to convert carbon dioxide and water into glucose and oxygen.

Rubisco

Ribulose bisphosphate carboxylase/oxygenase, the enzyme that catalyzes the first step of the Calvin cycle.

CAM Plants

Plants that fix carbon dioxide at night into organic acids to minimize water loss; used by succulents.

C4 Plants

Plants that utilize a four-carbon compound to fix carbon dioxide during photosynthesis to increase efficiency and reduce photorespiration.

Electron Transport Chain

A series of protein complexes in the thylakoid membrane that transfer electrons and pump protons to generate ATP and NADPH.

Photosystem II

The complex in the chloroplast thylakoid membrane where light is absorbed and water is split to release oxygen.

Calvin Cycle

The light-independent reactions of photosynthesis that occur in the stroma to convert CO2 to glucose using ATP and NADPH.

Chlorophyll

The green pigment found in chloroplasts responsible for absorbing light energy during photosynthesis.

Light-dependent reactions

The first stage of photosynthesis where light energy is converted into chemical energy (ATP and NADPH) in the thylakoids.

Photophosphorylation

The process of adding a phosphate group to ADP to form ATP, driven by light energy during photosynthesis.

Chromoplasts

Plastids that contain pigments other than chlorophyll and are involved in photosynthesis and pigment storage.

Carotenoids

Accessory pigments found in plants that capture light energy for photosynthesis and provide colors such as yellow and orange.

Absorption spectrum

A graph showing the range of wavelengths absorbed by a pigment; indicates that chlorophyll a absorbs blue and red light.

Action spectrum

The effectiveness of different wavelengths of light in driving photosynthesis as measured by the rate of O2 production.

Light harvesting complex

A collection of proteins and pigments (accessory pigments) that capture light energy and transfer it to the reaction center.

NADPH

The reduced form of NADP+, an electron carrier that plays a crucial role in the Calvin cycle.