Ch 14 - Energy Generation in Mitochondria and Chloroplasts

Question 1

antenna complex

Answer 1

in chloroplasts and photosynthetic bacteria, the part of the membrane-bound photosystem that captures energy from sunlight; contains an array of proteins that bind hundreds of chlorophyll molecules and other photosensitive pigments

Question 2

ATP synthase

Answer 2

abundant membrane-associated enzyme complex that catalyzes the formation of ATP from ADP and inorganic phosphate during oxidative phosphorylation and photosynthesis

Question 3

carbon fixation

Answer 3

process by which green plants and other photosynthetic organisms incorporate carbon atoms from atmospheric carbon dioxide into sugars. the second stage of photosynthesis

Question 4

cell respiration

Answer 4

process by which cells harvest the energy stored in food molecules; usually accompanied by the uptake of O2 and release of CO2

Question 5

chemiosmotic coupling

Answer 5

mechanism that uses the energy stored in a transmembrane proton gradient to drive an energy-requiring process, such as the synthesis of ATP by ATP synthase or the transport of a molecule across a membrane

Question 6

chlorophyll

Answer 6

light-absorbing green pigment that plays a central part in photosynthesis

Question 7

chloroplast

Answer 7

specialized organelle in algae and plants that contains chlorophyll and serves as the site for photosynthesis

Question 8

cytochrome

Answer 8

a family of membrane-bound, colored, heme-containing proteins that transfers electrons during cellular respiration and photosynthesis

Question 9

cytochrome c oxidase

Answer 9

protein complex that serves as the final electron carrier in the respiratory chain; removes electrons from cytochrome c and passes them to O2 to produce H2O

Question 10

electron-transport chain

Answer 10

a series of membrane-embedded electron carrier molecules that facilitate the movement of electrons from a higher to a lower energy level, as in oxidative phosphorylation and photosynthesis

Question 11

iron-sulfur center

Answer 11

tightly bound metal complex that carries electrons in proteins that operate early in the electron-transport chain; has a relatively weak affinity for electrons

Question 12

light reactions

Answer 12

in photosynthesis, the set of reactions that converts the energy of sunlight into chemical energy in the form of ATP and NADPH (stage 1 of photosynthesis)

Question 13

matrix

Answer 13

large internal compartment within a mitochondrion

Question 14

mitochondrion

Answer 14

membrane-enclosed organelle, about the size of a bacterium, that carries out oxidative phosphorylation and produces most of the ATP in eukaryotic cells

Question 15

nitrogen fixation

Answer 15

conversion of nitrogen gas from the atmosphere into nitrogen-containing molecules by soil bacteria and cyanobacteria; requires a great deal of energy

Question 16

oxidative phosphorylation

Answer 16

membrane-based process in bacteria and mitochondria in which ATP formation is driven by the transfer of electrons from food molecules to molecular oxygen

Question 17

photosynthesis

Answer 17

the process by which plants, algae and some bacteria use the energy of sunlight to drive the synthesis of organic molecules from carbon dioxide and water

Question 18

photosystem

Answer 18

large multiprotein complex containing chlorophyll that captures light energy and converts it into chemical-bond energy; consists of a set of antenna complexes and a reaction center

Question 19

quinone

Answer 19

small, lipid-soluble, mobile electron carrier molecule that functions in the respiratory and photosynthetic electron-transport chains

Question 20

reaction center

Answer 20

in photosynthetic membranes, a protein complex that contains a special pair of chlorophyll molecules; it performs the photochemical reactions that convert the energy of photons (light) into high-energy electrons for transport down the photosynthetic electron-transport chain

Question 21

redox pair

Answer 21

two molecules that can be interconverted by the gain or loss of an electron; for example NADH and NAD+

Question 22

redox potential

Answer 22

a measure of the tendency of a given redox pair to donate or accept electrons

Question 23

redox reaction

Answer 23

a reaction in which electrons are transferred from one chemical species to another. an oxidation-reduction reaction

Question 24

respiratory enzyme complex

Answer 24

set of proteins in the inner mitochondrial membrane that facilitates the transfer of high-energy electrons from NADH to water while pumping protons into the intermembrane space

Question 25

stroma

Answer 25

in a chloroplast, the large interior space that contains the enzymes needed to incorporate CO2 into sugars during the carbon-fixation stage of photosynthesis; equivalent to the matrix of a mitochondrion

Question 26

thylakoid

Answer 26

in chloroplast, the flattened, disclike sac whose membranes contain the proteins and pigments that convert light energy into chemical-bond energy during photosynthesis