Chapter 14

Question 1

Two steps for using an electrochemical proton gradient to synthesize ATP

Answer 1

1. energy released by electron transport is used to pump protons across membrane
2. energy stored in the proton gradient is harnessed by ATP synthase to make ATP

Question 2

chemiosmotic coupling

Answer 2

mechanism that uses the energy stored in a transmembrane proton gradient to drive an energy-requiring process

Question 3

functions of the mitochondris

Answer 3

production of ATP
regeneration of NAD+
precursors for synthesis of amino acids, nucleotides, fatty acids
synthesis of heme and iron-sulfur clusters
cell signaling
generation of reactive oxygen species
regulation of apoptosis

Question 4

is the inner or outer mitochondrial membrane more permeable?

Answer 4

outer

Question 5

site of oxidative phosphorylation

Answer 5

inner mitochondrial matrix

Question 6

final electron acceptor of the electron transport chain

Answer 6

O2

Question 7

oxidative phosphorylation definition

Answer 7

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

Question 8

respiratory enzyme complex definition

Answer 8

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

Question 9

function of NADH dehydrogenase complex

Answer 9

accepts electrons from NADH

Question 10

ATP synthase defintion

Answer 10

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

Question 11

how many molecules of ATP does ATP synthase produce for one revolution

Answer 11

3

Question 12

electrochemical proton gradient is used for _______ and _______

Answer 12

generation of ATP
transport of selected metabolites and proteins across the inner mitochondrial membrane

Question 13

what mobile carrier do FADH2 molecules pass their electrons to

Answer 13

ubiquinone

Question 14

Direct products of glycolysis

Answer 14

2 NADH
2 ATP

Question 15

direct products of pyruvate oxidation to acetyl CoA (two per glucose)

Answer 15

2 NADH

Question 16

direct products of the complete oxidation of the acetyl group of acetyl CoA (two per glucose)

Answer 16

6 NADH
2 FADH2
2 GTP

Question 16

what do chloroplasts do

Answer 16

capture light energy and use it to produce ATP and NADPH

Question 17

carbon fixation

Answer 17

activated carriers are used to convert CO2 into organic molecules that serve as precursors for sugars

Question 18

stroma defintion

Answer 18

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

Question 19

thylakoid definition

Answer 19

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

Question 20

stage 1 of photosynthesis

Answer 20

light reactions
chlorophyll supplies electrons that have energy absorbed from sunlight to the electron-transport chain which uses the energy to make a proton gradient to produce ATP
final electron acceptor is NADP+

Question 21

stage 2 of photosynthesis

Answer 21

ATP and NADPH produced in stage 1 are used to drive carbon-fixation reactions
light-independent reactions

Question 22

photosystem definition

Answer 22

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 23

antenna complex definition

Answer 23

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 24

reaction center definition

Answer 24

a protein complex that contains a special pair of chlorophyll molecules
performs the photochemical reactions that convert the energy of photons into high-energy electrons for transport

Question 25

function of photosystem II

Answer 25

first photosystem
absorbs light energy
its reaction center passes electrons to the mobile electron carrier plastoquinone which transfers the high-energy electrons to a proton pump

Question 26

photosystem I function

Answer 26

second photosystem
reaction center passes its high-energy electrons to the mobile electron carrier ferredoxin which brings them to an enzyme that uses the electrons to reduce NADP+ to NADPH

Question 27

how are missing electrons replaced in photosystem II

Answer 27

replaced by a special manganese-containing protein complex that removes electrons from water
produces O2

Question 28

how are missing electrons replaced in photosystem I

Answer 28

come from photosystem II as photosystem I is the final electron acceptor for electrons from photosystem II

Question 29

carbon fixation definition

Answer 29

process by which green plants and other photosynthetic organisms incorporate carbon atoms from atmospheric carbon dioxide into sugars

Question 30

how much ATP and NADPH is consumed in the citric acid cycle

Answer 30

9 ATP
6 NADPH

Question 31

nitrogen fixation definition

Answer 31

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