Biochem Muscle Weakness Atp 2

Front 1

electron flow in ETC is driven by?

Back 1

redox potential, from most negative to most positive

Front 2

where are protons pumped in the ETC? (what complex's)

Back 2

I III IV

Front 3

What is the relationship between reduction potential and the ratio of oxidized to reduced forms of the substance?

Back 3

more OXIDIZED means HIGHER Reduction Potential


If E'o is positive it means the substance has a higher affinity for electrons(than hydrogen electrode)

Front 4

what is the relationship between delta E and delta G (equation)

Back 4

DIRECT relationship

delta G = -nF delta E

n = electrons
F = eV

Front 5

what is the relationship between the reduction potentials of a system and the concentration of the oxidized and reduced forms?

Back 5

E = E'o + [RT/nF] [ln(ox/red)]

higher oxidation form means more positive potential energy

Front 6

what are the electron carriers in a broader sense of the ETC

Back 6

coenzymes

specifically flavins, iron sulfur centers and hemes

Front 7

what is barth syndrome?

Back 7

defect in cardiolipin, since cytochrome C is tethered to inner mitochondrial membrane by cardiolipin, a defect would lead to ETC dysfunction

Front 8

how many electrons does the ETC carry?

Back 8

2 e

Front 9

the reduction of O2 to water often causes what to form, how do you prevent it?

Back 9

causes ROS to form, need 4 electrons to prevent formation

Front 10

nicotinamide nucleotides are weakly bound to enz's and are therefore?
coenz prosthetic group
coenz cosubstrate
coenz cofactor

Back 10

coenz cosubstrate

most nicotinamide nucleotides are free and in equil with their enzyme substrates

Front 11

NAD and NADP
oxidants or reductants strong or weak

Back 11

weak oxidants
always accept two e and a proton

Front 12

NADP is in the ox or reduced state primarily(in cells)

Back 12

reduced state NADPH, because it functions more in anabolism

NAD is 90% oxidized state
functions more in catabolism

Front 13

flavin nucleotides are
coenz prosthetic
coenz co substrate
coenz cofactor

Back 13

prosthetic groups

Front 14

COMPLEX I
mechanism

Back 14

NADH-UBQ oxidoreductase
takes two e from nadh into the FMN group, single electrons are then transfered to FeS centers and eventually to UBQ

Front 15

COMPLEX II

Back 15

Succinate dehydrogenase

takes electrons from Succinate via FAD and transfers along FeS centers

Front 16

what complex's transfer electrons to ubiquinone?

Back 16

complex I and II

glycerol 3 phosphate dehydrogenase

ETF(e transport flavoprotein)-UBQ oxidorecutase) . . .from fatty acid cycle

Front 17

which complex's have heme groups?

Back 17

IV III and cytochrome C

Front 18

why does hemoglobin bind O2 and cytochromes do not?

Back 18

b/c cytochromes have amina acid side chains at some of their coordination sites, thats why they do e transfer (ox/red) instead

Front 19

what is the exception to the O2 vs ox/red situation?

Back 19

cytochrome A binds O2 AND is oxidized as a result, last cytochrome of chain

Front 20

characteristic features of heme
A
B
C
and what structures they are found in

Back 20

A:
cytochrome C oxidase complex IV, a and a3
has a long isoprenoid chain
attaches to apoprotein thru aa coordination bond

B:
hemoglobin myoglobin, complex III
simple/plain

c:
Cytochrome C
side chains cys cov bond to protein through thioether linkage, structure is conserved, side chains met and his coordination bondsz to apoprotein

Front 21

describe the heme in cytochrome a3

Back 21

coordination bonds to his and copper "B"

Front 22

describe the redox centers in complex III

Back 22

prosthetic groups

cyt c1, cyt b, reisk fe-s

each monomer of the 11 subunit complex is pear shaped with protuberances into mito matrix and reisk/c1 protruding into intermem space

Front 23

the Q cycle
general description

Back 23

happens in complex III, UBQ-Cytochrome C oxidoreductase
reduced Q transfers e to two cytochrom C molecules, uses heme prosthetic groups as e carriers

Front 24

The Q cycle in depth

Back 24

ubiquinol transfers an e to reisk which undergoes conformational change and transfers it to cyt c1
transfers an e to bL and then to bH

OVERALL 4 protons pumped into intermembrane space and 2 e transferred to the single e carrier cyt C1

Front 25

complex IV where are the three essential subunits encoded?

Back 25

mitochondrial DNA
remaining 10 are in nuclear DNA

Front 26

subunit 1

Back 26

12 transmem helices

Front 27

subunit II

Back 27

binds cyt c, large domain protruding into cytosolic face of inner membrane

Front 28

complex IV how does it work

Back 28

cyt c transfers e to Cu.A
Cu.A transfers to heme a
heme a transfers to binuclear center (heme a3-Cu.B)

binuclear center transfers to O2 using two H from matrix to make water (this helps with the proton grad)

overall 4 protons pumped into intermem space,

Front 29

overall how many protons go to the cytosol for every 4 pumped taken up from the matrix

Back 29

2

Front 30

what is a negative effect of repurfusion of oxygen to ischemic areas after a myocardial infarction?

Back 30

formation of ROS reactive oxygen species

Front 31

how do you make superoxide
hydrogen peroxide
hydroxyl radical

Back 31

superoxide, add an e to O2
H2O2, add 2 H and e to superoxide
OH, add a e and H to H2O2, makes water and OH radical

Front 32

how does the cell defend against ROS

Back 32

superoxide dismutase and catalase

Front 33

what do superoxide dismutase and catalase do biochemically

Back 33

superoxide: converts 2 superoxides to H2O2 and oxygen

catalase: converts 2 H2O2 to water and oxygen

NOTE: hydroxyl radical can from from H2O2 by addition of an e and H, This radical is converted to water by adding another e and H

Front 34

what types of groups do iron sulfide compounds come in?

Back 34

2,3,4 or 8 irons in the same protein

8 irons carry 2 e, everything else carries 1

Front 35

what is the defining property of ubiquinone in chemical structure

Back 35

long hydrophobic side chain that allows it to be free in the lipid core of the mem

Front 36

what are the two broad categories of flavin nucleotides

Back 36

oxidases
dehydogenases

dehydrogenases are the ones in the ETC, must be RE-OXIDIZED

Front 37

heme a

Back 37

binds oxygen and is oxidized as a result

Front 38

heme c

Back 38

cov bond through cys

coordination sites taken up by his and met (why it can't bind Oxygen)