test 4 lec 23

Question 1

what bacteria uses more than one type of metabolism

Answer 1

rhodopseudomonas palustris

Question 2

delta pH is what

Answer 2

the H+ concentration difference

Question 3

what is photoheterotrophs

Answer 3

absorb light to make ATP, while incorporating pre-formed carbon compounds for biosynthesis

Question 4

where is the ETS located

Answer 4

in a membrane that separates two aqueous compartments

Question 5

what are great electron acceptors

Answer 5

H2O and O2

Question 6

what is a proton motive force

Answer 6

stores energy to make ATP

drives protons across the membrane

Question 7

what are the three major classes of prokaryotic energy acquiring processes using an ETS

Answer 7

organotrophy
lithotrophy
phototrophy

Question 8

how else is electrical potential and pH difference affected

Answer 8

includes charges on other ions

metabolic generation of acids or pH changes outside the cell

Question 9

how do microbes transfer energy

Answer 9

by moving electrons

Question 10

what is photoautotrophs

Answer 10

couple photolysis to CO2 fixation for biomass production

Question 11

what are obligate autotrophs

Answer 11

fix CO2 for biosynthesis

Question 12

besides ATP synthesis what drive many cell processes

Answer 12

delta p

Question 13

what are facultative lithotrophs

Answer 13

chemooganotrophs that catabolize many substrates

oxidizing sulfur compounds

Question 14

where is energy stored when protons are pumped across the membrane

Answer 14

electrical potential and the pH difference

Question 15

what is the proton motive force

Answer 15

the sequential transfer of electrons from one ETS protein to the next yields energy to pump ions across the membrane

Question 16

ETS proteins and cofactors act as…

Answer 16

electron donors and acceptors, coupled with proton transporting across membrane

Question 17

function of proton potential

Answer 17

stores energy to drive H+ back across the membrane through devices such as ATP synthase

Question 18

what is phototrophy

Answer 18

involves light capture by chlorophyll, usually coupled by splitting of H2S or H2O or organic molecules

Question 19

function of ETS

Answer 19

transfers electrons onto membrane embedded carriers in a series of increasing reduction potential , ending at a terminal electron acceptor

Question 20

a more positive E’ means that

Answer 20

that reducing the electron acceptor yields more energy

Question 21

what is the chemiomotic theory

Answer 21

energy from electron transfer between membrane proteins is used to pump protons across the membrane, accumulating a higher H+ concentration in the compartment outside

Question 22

what does a negative E equal

Answer 22

energy is yielded by the reverse reaction

Question 23

what is the reduction potential

Answer 23

a measure of the tendency of a molecule to accept electrons

Question 24

how do electrons move

Answer 24

from reduced electron donors to oxidized electron acceptors

Question 25

what is lithotrophy

Answer 25

involves inorganic electron donor donors and inorganic or organic terminal acceptors

Question 26

what are chemolithoautotrophs

Answer 26

obligate autotrophs, fixing CO2 for biosynthesis

Question 27

a gain of electrons yields what

Answer 27

energy

Question 28

what is the proton potential

Answer 28

the H+ concentration difference plus the charge differen

Question 29

a more negative E’ means that

Answer 29

oxidizing the electron donor yields more energy

Question 30

how does ETS convert its energy

Answer 30

ion potential or electrochemical potential between two compartments separated by the membrane

Question 31

the ETS must accept electrons from

Answer 31

an initial electron donor consisting of an organic molecule or a reduced mineral

Question 32

the standard reduction potential represents what

Answer 32

the standard reduction potential per electron

Question 33

what is organotrophy

Answer 33

involves organic electron donors and inorganic or organic terminal electron acceptor

Question 34

oxidoreductases consist of

Answer 34

multiple protein complexes that include cytochromes and non cytochromes proteins

Question 35

what happens if the membrane is disrupted so that protons leak

Answer 35

small leak can dissipate all the energy store as delta pH

uncouple electron transport from ATP synthesis through the membrane ATP synthase

Question 36

what is a redox couple

Answer 36

the oxidized and reduced states of a compound

Question 37

what are oxidoreductases

Answer 37

electron transport proteins

oxidize one substrate and reduce another

Question 38

what are standard reduction potentials

Answer 38

standard values of E

Question 39

positive E is equal to what Delta G

Answer 39

neg

Question 40

characterisitcs of rhodopseudomonas palustris

Answer 40

gram neg
purple nonsulfur photosynthetic bacterium
photolithoheterotroph
found in soil and water
in O2, use photosynthesis or lithotrophy
no O2, eats everything to obtain reduced electron carriers

Question 41

a complete redox reaction combines

Answer 41

two redox couples
one accepting electrons
and one donating electrons