Biology Chapter 10

Photosynthesis

The process that converts solar energy into chemical energy within chloroplasts.

Chloroplasts

Organelles in plants and other photosynthetic organisms where photosynthesis occurs.

Stroma

The dense fluid inside chloroplasts surrounding the thylakoids.

Thylakoids

Connected sacs within the chloroplast that compose a third membrane system.

Light reactions

The first stage of photosynthesis that converts solar energy to the chemical energy of ATP and NADPH.

Calvin cycle

The second stage of photosynthesis that uses ATP and NADPH to convert CO2 into sugar.

Chlorophyll

The green pigment in plants that absorbs light for photosynthesis.

Autotrophs

Organisms that can produce their own food through photosynthesis.

Heterotrophs

Organisms that cannot produce their own food and rely on consuming other organisms.

Electromagnetic spectrum

The entire range of electromagnetic energy, including visible light.

Wavelength

The distance between crests of electromagnetic waves.

Absorption spectrum

A graph that shows a pigment's light absorption versus wavelength.

Rubisco

The enzyme that catalyzes the first step of the Calvin cycle, fixing CO2.

Linear electron flow

The primary pathway of electron flow during the light reactions in photosynthesis.

Cyclic electron flow

A pathway of electron flow that produces ATP but not NADPH, using only photosystem I.

Glyceraldehyde 3-phosphate (G3P)

The sugar produced in the Calvin cycle for net synthesis.

Photophosphorylation

The process of generating ATP from ADP in the light reactions.

Proton gradient

A difference in proton concentration across a membrane, driving ATP synthesis.

NADP+

The electron acceptor in the light reactions, which is reduced to NADPH.

Electron transport chain

A series of proteins that transfer electrons during the light reactions, creating ATP.

Stomata

Microscopic pores on leaves that allow CO2 to enter and O2 to exit.