Chapter 7 Biology Concepts And Connections

Front 1

photosynthesis

Back 1

the process by which plants, autotrophic protists, and some bacteria use light energy to make sugars and other organic food molecules from carbon dioxide and water

Front 2

autotrophs

Back 2

an organism that makes its own food (often by photosynthesis), therby sustaining itself without eating other organisms or their molecules. Plants, algae, and numerous bacterias.

Front 3

producers

Back 3

an organism that makes organic food molecules from CO2, H2O and other inorganic raw materials: a plant, alga, or autotrophic prokaryote

Front 4

photoautotrophs

Back 4

an organism that obtains energy from sunlight and carbon from CO2 by photosynthesis

Front 5

chlorophyll

Back 5

a green pigment located within the chloroplasts of plants, algae, and certain prokaryotes

Front 6

mesophyll

Back 6

the green tissue in the interior of the leaf;a leaf's ground tissue system; the main site of photosynthesis

Front 7

stomata

Back 7

a pore surrounded by guard cells in the epidermic of a leaf. When they are open, CO2 enters a leaf and water and O2 exit. A plant conserves water when these are closed

Front 8

stroma

Back 8

the fluid of the chloroplasy surrounding the thylakoid membrane; involved in the synthesis or organic molecules from carbon dioxide and water

Front 9

thylakoids

Back 9

one of a number of disk-shaped membranous sacs inside a chloroplast. They contain chlorophyll and the enzymes of the light reactions of photosynthesis.

Front 10

grana

Back 10

a stack of hollow disks formed of thykaloid membrane in a chloroplast. They are they sites where light energy is trapped by chlorophyll and converted to chemical energy during the light reactions of photosynthesis

Front 11

light reactions

Back 11

the first of two stages in photosynthesis; the steps in which solar energy is absorbed, and converted to chemical energy in the form of ATP and NADPH. They power the sugar-producing Calvin cycle but produce no sugar themselves

Front 12

calvin cycle

Back 12

the second of two stages of photosynthesis; a cyclic series of chemical reactions that occur in the stroma of a chloroplast, using the carbon in CO2 and the ATP and NADPH produced by the light reactions to make the energy-rich sugar molecule G3P

Front 13

carbon fixation

Back 13

the incorporation of carbon from atmospheric CO2 into the carbon in organic compounds. During photosynthesis in a C3 plant, carbon is fixed into a three-carbon sugar as it enters the Calvin cycle. In C4 and CAM plants, carbon is fixed into a four-carbon sugar

Front 14

electromagnetic spectrum

Back 14

the entire spectrum of radiation ranging in wavelength from less than a nanometer to more than a kilometer

Front 15

wavelength

Back 15

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

Front 16

photon

Back 16

a fixed quantity of light energy. the shorter the wavelength of light, the greater the energy of this

Front 17

photosystem

Back 17

a light capturing unit of a chloroplast's thylakoid membrane, consisting of a reaction center complex surrounded by numerous light harvesting complexes

Front 18

reaction center complex

Back 18

in a photosystem in a chloroplast, the chlorophyll a molecules and the primary electron acceptor that trigger the light reactions of photosynthesis. The chlorophyll donates an electron excited by light energy to the primary electron acceptor, which passes an electron to an electron transport chain

Front 19

photophosphorylation

Back 19

the production of ATP by chemiosmosis during the light reactions of photosynthesis

Front 20

C3 plants

Back 20

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 21

photorespiration

Back 21

in a plant cell, the breakdown of a two-carbon compound produced by the Calvin cycle. The Calvin cycle produces the two-carbon compound, instead of its usual three-carbon product G3P, when leaf cells fix O2, instead of CO2. Produces no sugar molecules or ATP

Front 22

C4 plants

Back 22

a plant that prefaces the Calvin cycle with reactions that incorporate CO2 into four-carbon compounds, the end product of which supplies CO2 for the Calvin cycle

Front 23

CAM plants

Back 23

a plant that uses an adaptation for photosynthesis in arid conditions in which carbon dioxide entering open stomata during the night is converted to organic acids, which release CO2 for the Calvin cycle during the day, when the stomata are closed

Front 24

greenhouse effect

Back 24

the warming of the atmosphere caused by CO2, CH4, and other gases that absorb infrared radiation and slow its escape from Earth's surface

Front 25

global warming

Back 25

a slow but steady rise in Earth's surface temperature, caused by increasing concentrations of greenhouse gases in the atmosphere