Chapter 8 - Photosynthesis

Photosynthesis

Photosynthesis

Process that uses solar energy to convert carbon dioxide (CO2) and water (H2O) into sugar and oxygen (O2).

Light Reactions

Reactions in photosynthesis that directly require light, occurring in the thylakoids of chloroplasts, converting solar energy into short-term chemical energy (ATP, NADPH).

Calvin Cycle

Light-independent reactions that fix CO2 into sugar, occurring in the stroma of chloroplasts, using ATP and NADPH produced in the light reactions.

Chlorophyll

A pigment that absorbs red and blue light, reflecting and transmitting green light, essential for photosynthesis.

Thylakoid

Membrane-bound structure within chloroplasts where light reactions occur, containing chlorophyll and other pigments.

Proton Gradient

A difference in hydrogen ion concentration across a membrane, used to generate ATP during photosynthesis.

Rubisco

An enzyme that catalyzes the first step of the Calvin Cycle, fixing CO2 into organic compounds.

Photorespiration

A process where Rubisco reacts with O2 instead of CO2, leading to a waste of energy and carbon in C3 plants.

C3 Photosynthesis

A type of photosynthesis where the first stable compound is a 3-carbon sugar (PGA), typical in most plants.

C4 Photosynthesis

A type of photosynthesis where the first stable compound is a 4-carbon molecule (OAA), allowing plants to minimize photorespiration.

CAM Photosynthesis

A type of photosynthesis in which stomates open at night to fix CO2, preventing water loss during the day.

ATP Synthase

An enzyme that synthesizes ATP from ADP and inorganic phosphate, utilizing the proton gradient created during light reactions.

Accessory Pigments

Pigments such as chlorophyll b and carotenoids that assist in capturing light energy for photosynthesis.

Electron Transport Chain

A series of proteins in the thylakoid membrane that transfer electrons, generating a proton gradient and producing ATP and NADPH.