Deck 15: Atp Production Ii: Tca Cycle and Oxidative Phosphorylation

Question 1

In ge nera l, the fun ction o f the w ater s olub le vitam ins is to

A) Be electron acceptors during oxidation-reduction reactions
B) Serve as cofactors for enzymatic reactions
C) Take part in cellular signaling
D) Regulate gene expression
E) Direct the synthesis of proteins

Answer 1

B

Question 2

The series of react ions that allows NADH and FADH₂ to be oxidized with the eventually reduction of O 2 to H₂O is called the

A) T C A c ycle
B) Glycolytic cascade
C) Pentose pathway
D) Elec tron tran sp ort c ha in
E) Oxidative phosphorylation

Answer 2

D

Question 3

NADH that feeds into the electron transport chain originates mainly from

A) Glycolysis in the cytosol
B) þ ox ida tion in th e m itoc ho nd ria
C) The T CA c ycle in the m itoc ho nd ria
D) Protein catabolism in the cytosol
E) þ oxidation in the peroxisomes

Answer 3

C

Question 4

Oxidative ph os ph or ylatio n requires ADP and Pi entry and ATP exit. How does ATP get out of the mitochondria?

A) It is transported out of the mitochondria on a carrier, the ATP-ADP translocase.
B) ATP ge ts o ut o f th e m itoc ho nd ria bundled inside little spheres of membrane called vesicles.
C) ATP is secreted out of the mitochondria like a neurotransmitter
D) ATP is transported out of the mitochondria in exchange for Pi on a ATP-Pi exchanger
E) AT P ex its the m itocho ndria on th e elec troph oretic unipo rt.

Question 5

Complete oxidation of pyruvate to CO₂ produces

A) 4 NADH, 1 FADH 2 , 1 GTP and 3 CO₂
B) 3 NADH, 1 FADH 2, 1 GTP and 3 CO₂
C) 3 NADH, 1 FADH 2, 1 GTP and 2 CO₂
D) 4 NADH, 1 FADH 2 , 1 GTP and 3 CO₂
E) 4 NADH, 1 FADH 2 , 1 GTP and 3 CO₂

Question 6

The m embrane potential across the inner mitochondrial membrane is established by

A) Pumping out Na+ ions by the Na, K-ATPase
B) Higher permeability to H +, wh ich ha s a hig he r c on ce ntr atio n in sid e th e m itoc ho nd ria
C) Higher permeability to H +, wh ich ha s a low er co nc en tra tion ins ide the m itoc ho nd ria
D) Pum ping o ut H + ion s by the elec tron tran sp ort c ha in
E) Pu m ping out K + ions by the Na, K-ATPase

Question 7

Cytosolic NADH

A) Enters the mitochondrial matrix through a countertransport mechanism
B) Enters the m itochondrial matrix by active transport
C) Enters the m itochondrial matrix by passive transport
D) En ter s th e m itoc ho nd ria l m atr ix b y os m os is
E) NADH does not cross the inner mitochondrial membrane

Question 8

Cytosolic reducing equivalents enter the electron transport chain by

A) Be ing ca rried b y m alate
B) Be ing ca rried b y pyruva te
C) Be ing ca rried b y glycero l-3-ph osp hate
D) Being carried by ADP
E) A and C are correct

Question 9

The energy for oxidative phosphorylation of ATP comes directly from

A) The high free energy of NADH relative to NAD +
B) The electroch em ical gradient of H + across the inner mitochondrial membrane
C) The high free energy of glucose relative to CO₂
D) The high free energy of O 2 relative to H 2O
E) The high free energy of FADH₂ relative to FADH

Question 10

W hy does NADH yield 3 ATP wh ile FADH₂ only yields 2 ATP?

A) NADH has a higher electrochemical potential than FADH₂
B) NADH enters the ETC at complex I while FADH₂ ente rs it at co m plex II
C) T he standard free energy difference between NADH and NAD+ exceeds the standard free energy difference between FADH₂ and FAD
D) The chemical energy stored in NADH is more than that stored in FADH₂
E) All of the above

Question 11

The po ten tial a cr os s th e m itoc ho nd ria l m em br an e is

A) About 180 mV, negative inside and across the inner mitochondrial membrane
B) About 85 mV, negative inside and across the inner mitochondrial membrane
C) About 180 mV, negative inside and across the outer mitochondrial mem brane
D) About 180 mV, positive inside and across the inner mitochondrial membrane
E) About 85 mV, positive inside and across the inner mitochondrial membrane

Question 12

Each turn of the TCA cycle yields

A) 4 NADH, 2 FADH 2 and 1 GTP
B) 4 NADH, 1 FADH 2 and 2 GTP
C) 3 NADH, 1 FADH 2 and 1 GTP
D) 3 NADH, 2 FADH 2 and 1 GTP
E) 3 NADH, 1 FADH 2 and 2 GTP

Question 13

The reaction catalyzed by pyruvate dehydrogenase occurs in the

A) Cytosol
B) Peroxisome
C) M itoc ho nd ria
D) ER lumen
E) Golgi stack

Question 14

NA DH feed s into th e elec tron tra nsp ort ch ain at

A) Com plex I
B) Coenzyme Q
C) Co m plex II
D) Co m plex III
E) Co m plex IV

Question 15

Complete oxidation of acetyl CoA to CO₂ produces

A) 4 NADH, 1 FADH 2 , 1 GTP and 3 CO₂
B) 3 NADH, 1 FADH 2, 1 GTP and 3 CO₂
C) 3 NADH, 1 FADH 2, 1 GTP and 2 CO₂
D) 4 NADH, 1 FADH 2 , 1 GTP and 3 CO₂
E) 4 NADH, 1 FADH 2 , 1 GTP and 3 CO₂

Question 16

NAD + is converted to NADH during

A) Oxidation reactions
B) G luc on eo ge ne sis
C) Reactions catalyzed by dehydrogenase enzymes
D) Pr ote in s ynth es is
E) Both A and C are correct

Question 17

The first reaction in which CO₂ is p ro du ce d d ur ing ca tab olis m of g luc os e is

A) Conversion of pyruvate to acetyl CoA
B) C on ve rs ion of p ho sp ho en olp yru va te to pyru vic ac id
C) Co nve rsion of su ccin ate to alpha ke togluta rate
D) Conversion of alpha ketoglutarate to succinyl CoA
E) Co nde nsa tion of oxa loac etate with ac etyl CoA to form citrate