Respiratory Chain & Oxidative Phosphorylation

Question 1

Which is able to capture more available free energy of respiratory substances?

Aerobic or Anaerobic

Answer 1

Aerobic

Question 2

Pxns present with myopathy, encepalopathy, and often lactic acidosis

Answer 2

Inherited defects of mitochondria

Question 3

Which membrane is selectively permeable? Outer or Inner

Answer 3

Inner

Question 4

Creatine kinase and adenylyl kinase are found in

Answer 4

The intermembrane space

Question 5

In the inner membrane which enzymes are present

Answer 5

Cardiolipin
ATP synthase
Resp chain enzymes and
Membrane transporters
Electron carriers  (complexes I-IV)

Question 6

Acyl coA synthetase

Glycerol phosphate acytransferase

Answer 6

Outer membrane

Question 7

Q and and cyt C are mobile. Which is a soluble protein

Answer 7

Q diffuses rapidly within the membrane while cytC is a soluble protein

Question 8

Q accepts electrons via Complexes I and II

True or Fals

Answer 8

True

Question 9

OXIDIZES REDUCING EQUIVALENTS & ACTS AS A PROTON PUMP

Answer 9

RESPIRATORY CHAIN

Question 10

Components of the respiratory Chain are Contained in

Answer 10

Four Large protein Complexes Embedded in the Inner Mitochondrial Membrane

Question 11

Components of the respiratory Chain Complexes

Answer 11

Flavoproteins & Iron-Sulfur proteins (Fe-S)

Question 12

Q accepts Electrons via

Answer 12

Complexes I & II

Question 13

Couples Electron Transfer to proton Transport in Complex III

Answer 13

The Q Cycle

Question 14

Molecular Oxygen Is reduced to Water via

Answer 14

Complex IV

Question 15

CREATES A PROTON GRADIENT WHICH DRIVES THE SYNTHESIS OF ATP

Answer 15

ELECTRON TRANSPORT VIA THE RESPIRATORY CHAIN

Question 16

Functions as a rotary Motor to Form aTp

Answer 16

Membrane-Located aTp Synthase

Question 17

PROVIDES MOST OF THE ENERGY CAPTURED DURING CATABOLISM

Answer 17

RESPIRATORY CHAIN

Question 18

respiratory Control Ensures

Answer 18

a Constant Supply of aTp

Question 19

THEORY THAT CAN ACCOUNT FOR RESPIRATORY CONTROL AND THE ACTION OF UNCOUPLERS

Answer 19

CHEMIOSMOTIC THEORY

Question 20

THE SELECTIVE PERMEABILITY OF THE INNER MITOCHONDRIAL MEMBRANE NECESSITATES

Answer 20

EXCHANGE TRANSPORTERS

Question 21

permit Specific Cations to penetrate Membranes

Answer 21

Ionophores

Question 22

Source of Intramitochondrial naDph

Answer 22

a proton-Translocating Transhydrogenase

Question 23

Oxidation of Extramitochondrial naDh Is Mediated by

Answer 23

Substrate Shuttles

Question 24

Ion Transport in Mitochondria Is

Answer 24

Energy Linked

Question 25

Facilitates Transport of high-Energy phosphate from Mitochondria

Answer 25

Creatine phosphate Shuttle

Question 26

Enzymes of the mitochondrial matrix include

Answer 26

Citric acid cycle enzymes β-oxidation enzymes Pyruvate dehydrogenase

Question 27

Oxidation of the major foodstuffs leads to the generation of reducing equivalents (2h) that are

Answer 27

collected by the respiratory chain for oxidation and coupled generation of atp.

Question 28

During the oxidation of Qh2 to Q, one electron is donated to cyt c via a rieske Fe-S and cyt c1 and the second to a Q to form the semiquinone via cyt bL and cyt bh, with 2h+ being released into the intermembrane space. a similar process then occurs with a second Qh2, but in this case the second electron is donated to the semiquinone, reducing it to Qh2, and 2h+ are taken up from the matrix.

Answer 28

The Q cycle.

Question 29

complexes I, III, and IV act as proton pumps creating a proton gradient across the membrane, which is negative on the matrix side. the proton motive force generated drives the synthesis of atp as the protons flow back into the matrix through the atp synthase enzyme

Answer 29

chemiosmotic theory of oxidative phosphorylation

Question 30

increase the permeability of the membrane to ions, collapsing the proton gradient by allowing the h+ to pass across without going through the atp synthase, and thus uncouple electron flow through the respiratory complexes from atp synthesis.

Answer 30

Uncouplers

Question 31

the enzyme complex consists of an F0 subcomplex which is a disk of “c” protein subunits. attached is a γ subunit in the form of a “bent axle.” protons passing through the disk of “c” units cause it and the attached γ subunit to rotate. the γ subunit fits inside the F1 subcomplex of three α and three β subunits, which are fixed to the membrane and do not rotate. aDp and pi are taken up sequentially by the β subunits to form atp, which is expelled as the rotating γ subunit squeezes each β subunit in turn and changes its conformation. thus, three atp molecules are generated per revolution.

Answer 31

Mechanism of aTp production by aTp synthase.

Question 32

the capacity of the respiratory chain itself, when all substrates and components are present in saturating amounts

Answer 32

State 3

Question 33

➀ phosphate transporter, ➁ pyruvate symport, ➂ dicarboxylate transporter, ➃ tricarboxylate transporter, ➄ α-ketoglutarate transporter, ➅■adenine nucleotide transporter.

Answer 33

Transporter systems in the inner mitochondrial membrane

Question 34

inhibit (⊝) the Transporter systems in the inner mitochondrial membrane.

Answer 34

N-ethylmaleimide, hydroxycinnamate, and atractyloside

Question 35

shuttle for transfer of reducing equivalents from the cytosol into the mitochondrion.

Answer 35

Glycerophosphate

Malate

Question 36

α-Ketoglutarate transporter and glutamate/aspartate transporter (note the proton symport with glutamate).

Answer 36

Malate shuttle

Question 37

allows rapid transport of high-energy phosphate from the mitochondrial matrix into the cytosol. (cKa, creatine kinase concerned with large requirements for atp, eg, muscular contraction; cKc, creatine kinase for maintaining equilibrium between creatine and creatine phosphate and atp/aDp; cKg, creatine kinase coupling glycolysis to creatine phosphate synthesis; cKm, mitochondrial creatine kinase mediating creatine phosphate production from atp formed in oxidative phosphorylation;

Answer 37

creatine phosphate shuttle of heart and skeletal muscle

Question 38

well-known poisons arrest respiration by inhibition of the respiratory chain.

Answer 38

cyanide

Question 39

special exchange transporters span the membrane to allow ions such as OH−, ATP4−, ADP3−, and metabolites to pass through without discharging the electrochemical gradient across the membrane because

Answer 39

inner mitochondrial membrane is impermeable to protons and other ions,

Question 40

ATP synthase spans the membrane and acts like a rotary motor using the potential energy of

Answer 40

proton gradient or proton motive force to synthesize ATP from ADP and Pi.

Question 41

grouped into four respiratory chain complexes in the inner mitochondrial membrane.

Answer 41

redox carriers

Question 42

Virtually all energy released from the oxidation of carbohydrate, fat, and protein is made available in mitochondria as

Answer 42

reducing equivalents

Question 43

reducing equivalents are funneled into the respiratory chain, where

Answer 43

they are passed down a redox gradient of carriers to their final reaction with oxygen to form water.