Ap Bio Chapter 10

Front 1

Calvin Cycle

Back 1

The second of two major stages of photosynthesis (flowing the light reactions) involving fixation of atmospheric CO2 and reduction of the fixed carbon into carbohydrate.

Front 2

chlorophyll a

Back 2

A photosynthetic pigment that participates directly in the light reactions, which convert solar energy to chemical energy.

Front 3

thylakoid space

Back 3

The space inside the thylakoids.

Front 4

cyclic electron flow

Back 4

A route of electron flow during the light reactions of photosynthesis that involves only photosystem I and that produces ATP but not NADPH or O2

Front 5

chlorophyll b

Back 5

An accessory to photosynthesis pigment that transfer energy to chloropyll "a"

Front 6

chloroplast

Back 6

An organelle found in plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of organic compound from carbon dioxide and water.

Front 7

carotenoid

Back 7

An accessory pigment, either yellow or orange, in the chloroplasts of plants and in some prokaryotes. By absorbing wave lengths of light that chlorophyll cannot, they broaden the spectrum of colors that can drive photosynthesis.

Front 8

PEP carboxylase

Back 8

An enzyme that adds CO2 to PEP to form oxaloacetate in mesophyll cells of C4 plants. It acts prior to photosynthesis.

Front 9

PEP

Back 9

An intermediate metabolite in the Embden-Myerhot glycolytic pathway.

Front 10

action spectrum

Back 10

A graph that profiles the relative effectiveness of different wave lengths of radiation in driving a particule process like photosynthesis

Front 11

wavelength

Back 11

The distance between crests of waves, such as those of the electromagnetic spectrum.

Front 12

Photosystem I (PS I)

Back 12

A light-capturing unit in a chloroplast's thylakoid membrane; it has two molecules of P700 chlorophyll "a" at its reaction center.

Front 13

photosystem II (PS II)

Back 13

One of the two light-capturing units in a chloroplast's thylakoid membrane. It has two molecules of P650 chlorophyll "a" at its reaction center.

Front 14

photophosphorylation

Back 14

The process of generating ATP from ADP and phosphate by means of chemiosmois, using a proton-motive force generated across the thylakoid membrane of the chloroplast or the membrane of certain prokaryotes during the light reactions of photosynthesis.

Front 15

photorespiration

Back 15

A metabolic pathway that consomes oxygen and ATP, releases CO2 and decreases photosynthetic output. It genrally occurs on hot, dry, bright days when stomata close and the O2/CO2 ration in the leaf increases, favoring the binding of O2 to rubsico instead of CO2.

Front 16

photosystem

Back 16

A light capturing unit located in the thylakoid membrane of the chloroplast or in the membrane of some prokaryotes, consisting of a reaction-center complex surrounded by numerous light harvesting complexes. There are two types that absorb light best at different wavelengths.

Front 17

spectrophotometer

Back 17

An instrument that measures the proportion of light of different wavelengths absorbed and transmitted by a pigment solution.

Front 18

Light Reactions

Back 18

The first of two stages of photosynthesis. These reactions, which occur on the thylakoid membranes of the chloroplast convert solar energy into chemical energy of ATP and NADPH, releasing oxygen in the process.

Front 19

absorption spectrum

Back 19

The range of a pigment's ability to absorb various wavelengths of light; also a graph of such range.

Front 20

CAM plants

Back 20

Plants with a photosynthetic adaptation that open their stomata at night and close them during the day, which helps the plants conserve water and prevent CO2 from entering the leaves.

Front 21

electromagnetic spectrum

Back 21

The entire spectrum of electromagnetic radiation ranging in wavelength from less than a nanometer to over a kilometer.

Front 22

granum

Back 22

A stack of membran-bounded thylakoids in the chloroplast. They function in the light reactions of photosynthesis.

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carbon fixation

Back 23

The initial incorporation of carbon from CO2 into an organic compound by an autotrophic organism.

Front 24

thylakoid

Back 24

A flattened, membraneous sac inside a chloroplast. They often exist in stacks called grana that are interconnected; their membrans contain molecular machinery used to convert light energy to chemical energy.

Front 25

stroma

Back 25

A dense fluid within the chloroplast surrounding the thylakoid membrane and containing ribosomes and DNA; involved in the synthesis of organic molecules from carbon dioxide and water.

Front 26

NADP+/NADPH

Back 26

An electron acceptor that temporarily stores energized electrons produced during the light reactions.

Front 27

reaction center complex

Back 27

A complex of proteins associated with a special pair of chlorophyll "a" molecules and a primary electron acceptor. Located centrally in a photosystem, it triggers the light reactions of photosynthesis. Excited by light energy, the pair of chloroplylls donate an electron to the primary electron acceptor, which passes an electron to an electron transport chain.

Front 28

PEP carboxylase

Back 28

An enzyme that adds CO2 to PEP to form oxalocetate in mesophyll cells of C4 plants. It acts prior to photosynthesis.

Front 29

carbon fixing reactions (carbon fixation)

Back 29

The initial incorporation of carbon from CO2 into an organic compound by an autotrophic organism.

Front 30

rubisco (RuPB carboxylase)

Back 30

The enzyme that catalyzes the first step of the Calvin cycle (the addition of CO2 to RuPB)

Front 31

primary electron acceptor

Back 31

In the thylakoid membrane of a chloroplast, a specialized molecules that shares the reaction center complex with a pair of chlorophyll a molecules and that accepts an electron from them.

Front 32

stomata

Back 32

A microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange between the environment and the interior of the plant.

Front 33

mesophyll

Back 33

Leaf cells specialized for photosynthesis. In C3 and CAM they're located between the upper and lower epidermis; in C4 plants they're located between the bundle-sheath cells and the epidermis.

Front 34

bundle sheath cells

Back 34

In C4 plants, a type of photosynthetic cell arranged into tightly packed sheaths around the veins of the leaf.

Front 35

C3 plant

Back 35

A plant that uses the Calvin cycle for the initial steps that incorporate CO2 into organic material, forming a three-carbon compound as the first stable intermediate.

Front 36

P680

Back 36

The reaction center chlorophyll (primary electron donor) of photosystem II that is most reactive and best absorbing light at 680nm

Front 37

PGA

Back 37

The 3 carbon molecule created from pGAL in glycolysis which is also produced in the Calvin Cycle in photosythesis.

Front 38

P700

Back 38

The reaction center chlorophyll (primary electron donor) or photosystem I that is most reactive and best absorbing light at wavelength 700nm

Front 39

C4 plant

Back 39

A plant that uses the Calvin cycle is preceded by reaction that incorporate CO2 into a four carbon compound, the end product of which supplies CO2 for the Calvin cycle.

Front 40

Hatch-Slack Pathway

Back 40

Used in C4 plants -- 4 carbon pathway

Front 41

Dark Reactions

Back 41

Part of photosynthesis that does not require light. Like the Calvin Cycle.

Front 42

energy capturing reactions

Back 42

"light reactions"

Front 43

photoelectric effect

Back 43

Electron are emitted from matter as a result of their absorption of energy from electromagnetic radiation of very short wavelength (like visible or ultraviolet light).

Front 44

G3P

Back 44

A sugar that is produced by the Calvin Cycle. It goes on to make glucose and other organic compounds.