Biology Chapter 7 Terms

Front 1

the cyclic series of reactions whereby carbon dioxide is fixed into carbohydrates during the light-independent reactions of photosynthesis; also called Calvin-Benson cycle .

Back 1

C3 cycle

Front 2

the series of reactions in certain plants that fixes carbon dioxide into oxaloacetic acid, which is later broken down for use in the cycle of photosynthesis.

Back 2

C4 pathway

Front 3

the initial steps in the cycle, in which carbon dioxide reacts with ribulose bisphosphate to form a stable organic molecule.

Back 3

carbon fixation

Front 4

a red, orange, or yellow pigment, found in chloroplasts, that serves as an accessory light-gathering molecule in thylakoid photosystems.

Back 4

carotenoid

Front 5

a process of ATP generation in chloroplasts and mitochondria. The movement of electrons down an electron transport system is used to pump hydrogen ions across a membrane, thereby building up a concentration gradient of hydrogen ions across the membrane; the hydrogen ions diffuse back across the membrane through the pores of ATP-synthesizing enzymes; the energy of their movement down their concentration gradient drives ATP synthesis.

Back 5

chemiosmosis

Front 6

a pigment found in chloroplasts that captures light energy during photosynthesis; absorbs violet, blue, and red light but reflects green light.

Back 6

chlorophyll

Front 7

a series of electron carrier molecules, found in the thylakoid membranes of chloroplasts and the inner membrane of mitochondria, that extract energy from electrons and generate ATP or other energetic molecules.

Back 7

electron transport chain

Front 8

the first stage of photosynthesis, in which the energy of light is captured as ATP and NADPH; occurs in thylakoids of chloroplasts.

Back 8

light-dependent reactions

Front 9

the second stage of photosynthesis, in which the energy obtained by the light-dependent reactions is used to fix carbon dioxide into carbohydrates; occurs in the stroma of chloroplasts.

Back 9

light-independent reactions

Front 10

the smallest unit of light energy.

Back 10

photon

Front 11

a series of reactions in plants in which replaces during the cycle, preventing carbon fixation; this wasteful process dominates when plants are forced to close their stomata to prevent water loss.

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photorespiration

Front 12

the complete series of chemical reactions in which the energy of light is used to synthesize high-energy organic molecules, normally carbohydrates, from low-energy inorganic molecules, normally carbon dioxide and water.

Back 12

photosynthesis

Front 13

in thylakoid membranes, a light-harvesting complex and its associated electron transport system.

Back 13

photosystem

Front 14

in the light-harvesting complex of a photosystem, the chlorophyll molecule to which light energy is transferred by the antenna molecules (light-absorbing pigments); the captured energy ejects an electron from the reaction center chlorophyll, and the electron is transferred to the electron transport system.

Back 14

reaction center

Front 15

the semi-fluid material inside chloroplasts in which the grana are embedded.

Back 15

stroma

Front 16

an adjustable opening in the epidermis of a leaf, surrounded by a pair of guard cells, that regulates the diffusion of carbon dioxide and water into and out of the leaf.

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stoma

Front 17

a disk-shaped, membranous sac found in chloroplasts, the membranes of which contain the photosystems and ATP-synthesizing enzymes used in the light-dependent reactions of photosynthesis.

Back 17

thylakoid