Photosynthesis and Energy Metabolism

These flashcards cover key vocabulary terms and concepts related to photosynthesis and energy metabolism.

Photoheterotrophs

Organisms that use light for energy and organic compounds from their environment as their carbon source.

Photoautotrophs

Organisms that use light for energy and CO2 as their carbon source, including plants, algae, and some bacteria.

Chloroplasts

Membrane-bound organelles found in plant cells and algae, responsible for photosynthesis.

Chlorophyll

The most common pigment in photosynthesis; it absorbs light energy and converts it into chemical energy.

Thylakoid

A membrane-bound compartment inside chloroplasts that converts light energy into chemical energy during photosynthesis.

Pigment

A molecule which absorbs light energy and converts it into chemical energy for use in photosynthesis.

Calvin Cycle

The light-independent reactions of photosynthesis that convert CO2 into glucose, utilizing ATP and NADPH.

3-Phosphoglycerate (3-PGA)

A 3-carbon molecule formed in the Calvin Cycle after CO2 fixation.

Glyceraldehyde-3-phosphate (G3P)

A 3-carbon sugar formed from 3-PGA during the Calvin Cycle and used in glucose synthesis.

C3 plants

Plants that use the standard Calvin Cycle for carbon fixation, producing 3-PGA as the first product.

C4 plants

Plants that utilize a modified pathway separating carbon fixation, producing a 4-carbon molecule before entering the Calvin Cycle.

CAM plants

Plants that fix carbon dioxide at night into 4-carbon acids to minimize water loss during the day.

Proton motive force (pmf)

The force generated by a proton gradient across a membrane, used to drive ATP synthesis.

Photon

The smallest unit of electromagnetic energy, exhibiting both wave-like and particle-like properties.

Photosystem

A complex of pigments and proteins embedded in thylakoid membranes that play a crucial role in the light-dependent reactions of photosynthesis.