Bios 303 Exam 2 MCQ

_____ molecules of CO2 are produced by the catabolism of one glucose molecule in the 10 steps of glycolysis. a). 0, b). 1, c). 2, d). 4, e). 6

a). 0

Glycolysis proceeds regardless of the presence or absence of oxygen. a). True, b). False

a). True

Protruding from the inner membrane of the mitochondria into the matrix are knob-like spheres. These knob-like spheres are the actual site of ATP synthesis. a). True b). False

a). True

The redox reaction: H2O = 1⁄2 O2 + 2H+ + 2e- , has a higher numerical value for redox potential than the redox reaction: NADH = NAD+ + H+ + 2e- . a). True, b). False

a). True

Both complex I and II transfers electrons to ______ in the electron transport chain. a). coenzyme Q, b). cytochrome c, c). oxygen, d). succinate dehydrogenase, e). NADH dehydrogenase

a). coenzyme Q

In electron transport, which respiratory complex is NOT involved in the flow of electrons from FADH2? a). complex I, b). complex II, c). complex III, d). complex IV, e). all of the above

a). complex I

The net free energy for the last 3 reactions in glycolysis is - 6 kcal/mol. These last 3 reactions are ________. a). exergonic, b). endergonic, c). dehydrogenase reactions, d). energy investments steps, e). highly caustic.

a). exergonic

The reaction, ATP -> ADP + P is thermodynamically ______, having a G value equal to _____. a). favorable, -7.3, b). favorable, +7.3, c). unfavorable, -7.3, d). unfavorable, + 7.3, e). none of the above

a). favorable, -7.3

__________ is the name of the enzyme that regenerates oxaloacetate in the TCA cycle. a). malate dehydrogenase, b). fumarase, c). succinate dehydrogenase, d). a-ketoglutarate dehydrogenase, e). isocitrate dehydrogenase

a). malate dehydrogenase

The products of fatty acid oxidation enter the TCA cycle at step ___. a). step 1, b). step 3, c). step 4, d). step 5, e). step 6

a). step 1

In which of the following steps in the TCA cycle are neither NADH or FADH2 produced? a). step 2, b). step 3, c). step 4, d). step 6, e). step 8

a). step 2

The phosphoester bond in ATP is cleaved upon the hydrolysis of ATP to ADP. a). True, b). False

b). False

Thermodynamically, the transfer of electron along the electron transport chain is ____________. a). unfavorable, b). favorable, d). at equilibrium, e). evident only during hypoxia (zero oxygen is present)

b). favorable

The citric acid cycle occurs in _____________. a). cytosol, b). matrix of the mitochondria, c). intermembrane space in the mitonchondria, d). oranges, e). primates only

b). matrix of the mitochondria

The change in Gibbs free energy tells us whether a reaction is thermodynamically favorable when the numerical value is ____________ . a). positive, b). negative

b). negative

As pyruvate is prepared for the TCA cycle, it undergoes a process of ___. a). reductive carboxylation, b). oxidative decarboxylation, c). oxidative carboxylation, d). reductive decarboxylation, e). CoQ reproduction

b). oxidative decarboxylation

ATP is a _____. a). deoxyribonucleic acid, b). ribonucleic acid, c). protein, d). lipid, e). carbohydrate

b). ribonucleic acid

In which step of the TCA cycle does a 4 carbon intermediate first get formed (hint: use the production of CO2 molecules to subtract carbons)? a). step 3, b). step 4, c). step 5, d). step 6, e). step 7

b). step 4

ATP is generated in the 10 step process called glycolysis by ________________. a). oxidative phosphorylation, b). substrate level phosphorylation, c). electron transport, d). ATP synthase, e). hydrolysis

b). substrate level phosphorylation

Tally up the ATPs that are produced by glycolysis of glucose and the subsequent oxidation of 2 pyruvate molecules (include substrate level phosphorylation and oxidative phosphorylation). Do not include ATPs from the TCA cycle. a). 2, b). 5, c). 10, d). 30, e). none of the above

c). 10

How many ATPs are produced by electron transport and oxidative phosphorylation from 2 FADH2 molecules produced during the TCA cycle? a). 1, b). 2, c). 3, d). 5, e). no ATPs are produced

c). 3

How many ATP molecules are produced by the catabolism of glucose to pyruvate (include any ATP molecules produced as a consequence of electron transport and oxidative phosphorylation)? a). 2, b). 4, c). 5, d). 6, e). 36

c). 5 (NADH --> ATP)=+1 more ATP

The name of the enzyme that performs the lysis step in glycolysis, splitting a 6 carbon sugar molecule into 2 - 3 carbon molecules is ______. a). hexokinase, b). phosphofructokinase, c). aldolase, d). triose phosphate isomerase, e). pyruvate kinase

c). aldolase

In glycolysis, which of the following molecules is oxidized to form 1,3 diphosphoglycerate? a). 3-phosphoglycerate, b). 2-phosphoglycerate, c). glyceraldehyde-3-phosphate, d). glucose, e). glucose-6-phosphate.

c). glyceraldehyde-3-phosphate

The enzyme that catalyzes step 6 in glycolysis is named ____________. a). triose phosphate isomerase, b). phosphofructokinase, c). glyceraldehyde-3-phosphate dehydrogenase, d). phosphoglyceerokinase, e). enolase

c). glyceraldehyde-3-phosphate dehydrogenase

Gluconeogenesis occurs in the cell _______. a). mitochondria, b). cytosol, c). nucleus, c). mitochondrial matrix, d). intermembrane space in the mitochondria, e). endoplasmic reticulum.

c). mitochondrial matrix

The second energy investment step in glycolysis occurs in _____. a). step 1, b). step 2, c). step 3, d). step 4, e). no addition energy beyond the first investment step is required.

c). step 3

1. An energy liberating pathway is also known as _______. a). metabolic, b). anabolic,c). catabolic, d). hydrogenation, e). all of the above

c.) Catabolic

Glycolysis uses up ___ ATPs and releases a total of ____ ATP molecules per 1 glucose. a). 4, 4, b). 2, 2, c). 4, 2, d). 2,4, e). 0,0

d). 2,4

The metabolic pathway producing glycogen is basically the reverse of glycolysis, except for ______. a). steps 1, 2, 3, b). steps 8, 9, 10, c). only step 6, d). all the kinase steps in glycolysis, e). gluconeogenesis is exactly the same as glycolysis except it is performed in reverse.

d). all the kinase steps in glycolysis

Cytochrome c oxidase is the major enzyme activity in complex ___ of the electron transport chain. a). complex I, b). complex II, c). complex III, d). complex IV, e). coenzyme Q

d). complex IV

The breakdown and storage of energy in carbohydrates is separated into different tissues. Gluconeogenesis stores ___ mainly in the ____. a). glucose, liver, b). glucose, muscle, c). glucose, kidney, d). glycogen, brain, e). none of the above.

d). glycogen, brain

Which glycolytic enzyme uses ATP as a substrate? a). alcohol dehydrogenase, b). phosphoglucoisomerase, c). aldolase, d). hexokinase, e). triose phosphate isomerase

d). hexokinase

Oxidation ______. a). involves the removal of oxygen atoms, b). is endothermic, c). occurs when an atom accepts electrons, d). is when energy is released, e). both b and c

d). is when energy is released

Why are the NADH molecules produced during glycolysis "worth less" (produce fewer net ATP molecules) than the NADH molecules produced by the TCA cycle? a). the NADH molecules produced by glycolysis are chemically different from those produced in the TCA cycle, b). the NADH molecules produced by glycolysis are used by fermentation reactions so they do not contribute to the overall ATP tally, c). the stepwise activation energies are higher for NADH produced by glycolysis, d). the NADH molecules produced by glycolysis need to be shuttled into the mitochondria and this required energy to accomplish, e). complex I in the electron transport chain does not accept these cytoplasmic NADH molecules are readily as the matrix NADH molecules.

d). the NADH molecules produced by glycolysis need to be shuttled into the mitochondria and this required energy to accomplish

A ____________ gradient is produced as a consequence of electron transport. a). pH, b). electrical, c). proton, d). nucleotide, e). a, b and c

e). a, b and c

Which is NOT a product of the TCA cycle? a). CO2, b). ATP/GTP, c). NADH, d). FADH2, e). acetylCoA

e). acetylCoA

A phosphoanhydride bond _____. a). is a high energy bond, b). has a standard free energy equal to -7.3 kcal/mol, c). is broken by hydrolysis, d). both a and b, e). choices a, b and c

e). choices a, b and c