Bio 20 Unit A Topic 2 - Photosynthesis

Calvin Cycle

Carbon fixation in which energy from ATP and NADPH is used to build high-energy compounds such as sugars

Photolysis

Process by which light energy breaks down a water molecule

Thylakoid

A flattened membrane sac inside the chloroplast, used to convert light energy into chemical energy.

Thylakoid membrane

The photosynthetic membrane within a chloroplast that contains light gathering pigment molecules and electron transport chains.

Lumen

Space within a thylakoid.

Stroma

Fluid portion of the chloroplast; outside of the thylakoids

NADP+

Carrier molecule that transfers high-energy electrons from chlorophyll to other molecules

ATP (adenosine triphosphate)

Main energy source that cells use for most of their work; in photosynthesis provides energy for the Calvin Cycle

Proton gradient

The product of the electron transport chain. A higher concentration of protons inside the membrane of the thylakoid than outside the membrane; is the driving force behind ATP synthesis.

Reduction

Gaining electrons

Oxidation

Losing electrons

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Chlorophyl

Green pigment in plants that absorbs light energy used to carry out photosynthesis

Photosystem

Cluster of chlorophyll and proteins found in thylakoids

Chemiosmosis

A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.

Light-dependent reactions

reactions of photosynthesis that use energy from light to produce ATP and NADPH

Electron Transport Chain (ETC)

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons along the thylakoid membrane, ending up with the electrons being added to NADP+