Week 9

Question 1

___________________ is also know as the Krebs cycles and tricarboxylic acid cycle, and it serves as the central metabolic hub.

Answer 1

The Citric Acid Cycle.

Question 2

In the first step of the Citric acid cycle, ______________ and ________________ undergo a claisen condensation to give _______________.

Answer 2

Oxaloacetate, acetyl-CoA, Citrate.

Question 3

______________ is the enzyme that catalyzes the formation of citrate.

Answer 3

Citrate synthase.

Question 4

In the second step of the Citric acid cycle, the ___________ alcohol of citrate is isomerized to a _____________ alcohol in ____________ .

Answer 4

Tertiary, Secondary, Isocitrate.

Question 5

______________ is the enzyme responsible for the isomerization of citrate to isocitrate.

Answer 5

Aconitase.

Question 6

In the third step of the Citric acid cycle, the __________ group of isocitrate is oxidized to a _____________, which leads to the loss of CO2 and formation of ____________.

Answer 6

Hydroxyl, Carbonyl, NADH.

Question 7

___________ is the enzyme that catalyzes the formation of _______________ from isocitrate.

Answer 7

Isocitrate dehydrogenase, alpha-ketogluturate.

Question 8

_____________ is the enzyme that catalyzes the formation of _____________ from alpha-ketogluturate.

Answer 8

Alpha-ketoglutarate dehydrogenase, Succinyl-CoA.

Question 9

____________ is the enzyme that catalyzes the formation of _______________ from Succinyl-CoA.

Answer 9

Succinyl-CoA synthase, Succinate.

Question 10

In the fifth step of the Citric acid cycle, hydrolysis of CoA from succinate is a _______________ phosphorylation, generating ______________.

Answer 10

Substrate-level, ATP or GTP.

Question 11

__________________ is the enzyme that catalyzes the formation of ______________ from succinate.

Answer 11

Succinate dehydrogenase, Fumarate.

Question 12

In the sixth step of the Citric acid cycle, saturated C-C bond is desaturated. The electrons are captured as ___________.

Answer 12

FADH2.

Question 13

__________________ is the enzyme that catalyzes the formation of ______________ from Fumarate.

Answer 13

Fumarase, Malate.

Question 14

In the seventh step of the citric acid cycle, the double bond is hydrated to an ________________.

Answer 14

Alcohol.

Question 15

__________________ is the enzyme that catalyzes the formation of ______________ from malate.

Answer 15

Malate dehydrogenase, Oxaloacetate.

Question 16

In the eighth step of the citric acid cycle, the hydroxyl group is oxidized to a ____________, yielding oxaloacetate and ______________.

Answer 16

Carbonyl, NADH.

Question 17

In the citric acid cycle, ____________ inhibits three dehydrogenases.

Answer 17

NADH.

Question 18

_________________ reactions replenish levels of citric acid cycle intermediates through a number of mechanisms.

Answer 18

Anaplerotic

Question 19

_______________ reactions occur when amine groups are shuttled to alpha-ketoglutarate to generate glutamate and a new alpha-keto acid from the old amino acid.

Answer 19

Transamination

Question 20

Levels of _______________ can be replenished by removal of the amine moiety from the amino acid glutamate.

Answer 20

Alpha-ketoglutarate.

Question 21

________________ can be generated via catabolism of odd-chain fatty acids, branched-chain amino acids, or the amino acids Thr and Met (via alpha-ketobutyrate)

Answer 21

Propionyl-CoA.

Question 22

Oxaloacetate replenishment can be generated from glutamate via ______________ transamination.

Answer 22

Aspartate.

Question 23

In the citric acid cycle, which enzyme catalyzes a non-reversible step?

Answer 23

Alpha-ketoglutarate dehydrogenase.

Question 24

In the citric acid and glycolysis, ___________ ATP, ___________ NADH, and ____________ FADH2 are generated from a single glucose molecule.

Answer 24

4,10, and 2.

Question 25

______________ occurs in the matrix and inner mitochondrial membrane.

Answer 25

Electron transport chain.

Question 26

Ubiquinone have 2 electron carriers on the ___________ groups.

Answer 26

Carbonyl.

Question 27

Higher energy electrons go to lower energy electrons to prevent the creation of _________________ species.

Answer 27

Reactive oxygen.

Question 28

______________ and ____________ are two important mitochondrial shuttles that transport metabolites from the mitochondrial matrix to the cytosol.

Answer 28

Glycerophosphate shuttle, and Aspartate-malate shuttle.

Question 29

The ________________ shuttle is reversible.

Answer 29

Aspartate-malate.

Question 30

________________ has the highest reducing potential, is a NADH dehydrogenase and the site of NADH oxidation.

Answer 30

Complex I.

Question 31

Complex I pumps ______________ out of the mitochondrial matrix.

Answer 31

4H+

Question 32

________________ is a succinate dehydrogenase and generates FADH2 and ubiquinone, no protons are pumped out of the matrix

Answer 32

Complex II

Question 33

____________________ is a ubiquinone/cytochrome c reductase. Pumps ________________ out of the mitochondrial matrix.

Answer 33

Complex III, 4H+

Question 34

________________ is a combination of oxidized and reduced forms of ubiquinone found in the mitochondrial membrane.

Answer 34

Q pool.

Question 35

____________ is a soluble electron carrier, receives electrons from complex III.

Answer 35

Cytochrome C

Question 36

Cytochrome C has a ____________ protein buried in its core, but is reduced through quantum mechanics. The ___________ protein carries _____________ electron.

Answer 36

Heme, One.

Question 37

The ETC has a higher reduction potential for ____________ and a lower reduction potential for ______________.

Answer 37

NADH, NAD+.

Question 38

_______________ is a cytochrome c oxidase, uses 4 different electron carriers and reduces O2 to H2O.

Answer 38

Complex IV.

Question 39

Complex IV takes _____________ electrons from cytochrome c and pumps ___________ out of the mitochondrial matrix.

Answer 39

4, 2H+.

Question 40

_____________ is an aggregated supercomplex containing complexes I,III, and IV.

Answer 40

Respirasome.

Question 41

The respirasome assists with ___________ channeling.

Answer 41

Substrate.

Question 42

______________ is a poison that affects the functions of complex IV.

Answer 42

Cyanide

Question 43

______________ is a poison that affects the functions of complex III.

Answer 43

Antimycin A1.

Question 44

______________ is a poison that affects the functions of complex II.

Answer 44

Carboxyl (fungicide).

Question 45

______________ is a poison that affects the functions of complex I.

Answer 45

Rotenone (insecticide).

Question 46

______________ are easily protonated/ deprotonated partially membrane soluble (hydrophobic but somewhat amphipathic) molecules which ferry protons and break down the gradient essentially at random.

Answer 46

Uncouplers.

Question 47

How many electrons can a fully oxidized quinone accept?

Answer 47

2

Question 48

_______________ is a multimeric enzyme that uses the electrochemical energy from the proton gradient to produce ATP from ADP and Pi.

Answer 48

ATP synthase.

Question 49

ATP synthesis is done by the __________ subunit, and H+ translocation is done by the _____________ subunit.

Answer 49

F1, F0.

Question 50

Protons move between a and b subunits of the ___________ complex.

Answer 50

F0.

Question 51

___________ and ____________ subunits also move through the hexer of alpha and beta subunits.

Answer 51

Gamma and Epsilon

Question 52

Always ___________ F1 rotations subunits but ___________ c's.

Answer 52

Six, 8-17.

Question 53

Humans have __________ c's.

Answer 53

8

Question 54

_________________ force is the electrochemical potential derived from the uneven distribution of electrons across the inner mitochondrial matrix.

Answer 54

Proton motive.

Question 55

_____________ potential is the higher concentration of protons on the outside of the membrane than the inside.

Answer 55

Chemical.

Question 56

______________ potential is the added positive charge that accumulates on the outside of the membrane.

Answer 56

Electric.

Question 57

ETC pumps protons _____________ the gradient.

Answer 57

Against.

Question 58

_______________ is an enzyme that transports ATP from the mitochondria in exchange for ADP.

Answer 58

ATP:ADP translocase.

Question 59

______________ domain is an integral membrane protein spanning six alpha helices.

Answer 59

Transmembrane

Question 60

_______________ ATPase have isolated factor involved in ADP phosphorylation.

Answer 60

F-type (F0/F1 ATPase)

Question 61

_______________, ________________, and ______________ are inhibitors of the F-type ATPase.

Answer 61

Oligomycin, Dicyclohexylcarbodiimide (DCC), Aurovertin B.

Question 62

_______________ ATPase are found in vacuoles and use energy of ATP hydrolysis to pump H+ or Na+ into vacuoles. It is also involved in endocytosis, protein trafficking, active transport of metabolite and neurotransmitter release.

Answer 62

V-type.

Question 63

_______________, ________________, ______________, and _________________ are inhibitors of the V-type ATPase.

Answer 63

Bafilomycin, Concanmycin, Apicularen, Lobatamide.

Question 64

Which subunits of ATP synthase rotate?

Answer 64

c, g, and e.