Photosynthesis and Pigments

These flashcards cover key terms and concepts related to photosynthesis and the role of pigments.

Photosynthesis

The biological process by which plants, algae, and some bacteria convert light energy into chemical energy.

Chlorophyll a

The primary pigment in most plants that absorbs light most efficiently in the blue-violet and red regions.

Light-dependent reactions

The first stage of photosynthesis occurring in the thylakoid membranes, where light energy is converted into ATP and NADPH.

Calvin cycle

The light-independent reactions of photosynthesis where ATP and NADPH are used to fix CO₂ into organic molecules.

RuBisCO

An enzyme that catalyzes the incorporation of CO₂ into ribulose-1,5-bisphosphate (RuBP) during the Calvin cycle.

Retention factor (Rf)

A value used in chromatography that indicates the ratio of the distance traveled by the pigment to the distance traveled by the solvent front.

Carotenoids

Accessory pigments that absorb light primarily in the blue and green regions and protect the photosynthetic apparatus.

Anthocyanins

Pigments that absorb light in the blue-green and UV regions, contributing to the coloration of leaves, especially in stressed plants.

Chromatography

A method used to separate and identify different pigments based on their solubility and interaction with a stationary phase.

Gas exchange in photosynthesis

A process where oxygen is produced as a byproduct of photosynthesis, measured by gas volume displacement.

Phenol Red

A pH indicator that turns yellow in acidic solutions, used to demonstrate the link between photosynthesis and respiration.

Photolysis

The process of splitting water molecules during the light reactions of photosynthesis, releasing oxygen.

Stroma

The fluid-filled space inside chloroplasts where the Calvin cycle occurs.

Thylakoid membranes

Membranes within chloroplasts that are the site of the light-dependent reactions of photosynthesis.

Absorption spectrum

A graph showing the wavelengths of light absorbed by photosynthetic pigments.

Action spectrum

A graph showing the efficiency of different wavelengths of light in driving photosynthesis.