Cellular Respiration: End of Chapter+ Learning Catalytics Quiz

Question 1

which energy-producing activity occurs in cytosol?

Answer 1

Glycolysis

Question 2

In mitochondria treated with dinitrophenol (DNP) how many molecules of ATP are derived from the oxidation of one molecule of NADH2?

Answer 2

0

Question 3

transfer of electrons in ETC is essential for ox phos to occur. which prosthetic group is found within an ETC complex that accepts the electrons from one mobile carrier and transfers them to another mobile carrier?

Answer 3

heme-b (in complex III)

Question 4

how many high-energy phosphates are generated through the complete metabolism of one acetyl CoA molecule to CO2 and H2O?

Answer 4

12

Question 5

under normal conditions, most regions of inner mitochondrial membrane are impermeable to?

Answer 5

H+

Question 6

immediate driving force that powers the phosphorylation of ADP to ATP by ATP synthase is?

Answer 6

gradient of H+ across the inner mitochondrial membrane

Question 7

The term oxidative phosphorylation refers to a process in which…?

Answer 7

electron transfer from substrate to oxygen provides energy to create a proton gradient, which then powers synthesis of ATP

Question 8

some patients with pyruvate dehydrogenase deficiency have an enzyme with low affinity for a vitamin cofactor. Which vitamin should be prescribed to manage these patients? not on test

Answer 8

Thiamine (vitamin B1)

Question 9

pyruvate dehydrogenase, alpha-ketoglutarate DH, and BC alpha-keto acid DH share one common protein, the E3 subunit. Which molecule is used as a prosthetic group by this subunit?not on test

Answer 9

FAD

Question 10

according to a 2006 report by health department, cyan dine produces toxic effects at levels > or equal to 0.05 mg/dL of blood, and deaths have occurred at 0.3mg/dL. The report also found that 1 hour of exposure to air containing 100 ppm of hydrogen cyanide gas can be life threatening, where are 10 minutes of exposure at 546 ppm can be deadly. At the molecular level, cyanide’s effects on mitochondria cause…?

Answer 10

decrease in TCA, ETC, and ATP formation

Question 11

the protein and lipid members of the ETC harbor molecules that facilitate the transfer of electrons. which of the following electron-carrying molecules is harbored in the protein that transfers electrons directly to oxygen?

Answer 11

heme-a 3

Question 12

electrons produced directly from pyruvate enter the mitochondrial electron transport chain as…?

Answer 12

NADH + H

Question 13

NADH generated in the cytoplasm is able to pass its electrons to oxygen via the mitochondrial electron transport system through which of the following mechanisms?

Answer 13

NADH reduces dihydroxyacetone phosphate to glycerol 3-phosphate, which can pass through the outer mitochondrial membrane to be deoxidized by systems associated with the electron transport system

Question 14

Consider the following reactions:
1. Glutamate +NH3 Glutamine +H2O (+3.4 Kcal/mol)
2. ATP + H2O ADP + Phosphate (-7.3 Kcal/mol)
Coupled: Glutamate + NH3 + ATP Glutamine+ ADP+ Phosphate in which direction would runs 1 and 2 and the coupled reaction proceed spontaneously?

Answer 14

Reaction 1: Left
Reaction 2: Right
Reaction 3: Right

Question 15

What are the complexes of the ETC inhibited by cyanide, oliomycin, and antimycin A?

Answer 15

cyanide: IV
oligomycin: V
antimycin A: III

Question 16

Barbiturates are toxic because they bind to which protein of oxidative phosphorylation?

Answer 16

Complex I (NADH DH)

Question 17

A newly developed lab method to isolate mito matrix as well as inner and outer mito membranes needs to be evaluated. Enzyme assays are commonly used in cell biology after separation to test cellular fractions for contamination with extraneous material. Which of the following enzymes could be used to test the matrix fraction for contamination with inner membrane and vice versa?

Answer 17

purity of matrix: glycerol 3 phosphate dehydrogenase (NADH dependent)
purity of inner membrane: cytochrome-c reductase

Question 18

48yo male is admitted to ER complaining of nausea, malaise, and palpitations. A physical exam reveals flushed, sweaty skin, tachycardia, rapid respiration, and a body temp of 105.8F. Upon questioning, he admits taking a “purely natural” weight reduction supplement obtained from an internet source. The active ingredient of the supplement is most likely…?

Answer 18

2.4- dinitrophenol

Question 19

about 15% of the world’s population currently is overweight, and 4% obese. According to WHO predictions, these numbers are expected to double by 2025, with a commensurate increase in cardiovascular disease, cancer, and Alzheimer’s disease. Because therapies based on reduction of energy intake have proven largely unsuccessful in stemming this tide, one current focus of research includes terrapins that increase energy expenditure. One obvious target is thermogenin (UCP1). How does UCP1 increase energy expenditure?

Answer 19

It binds a proton on the outer side of the inner mitochondrial membrane and then facilitates its release into the matrix

Question 20

Children ingest Implia present with nausea, vomiting, epigastric pain (upper abdominal pain), diarrhea, anxiety, and convulsions. Lab investigations revealed hypoglycemia, proteinuria, glucsuria, ketonuria, and high concentration of possum in urine. Needle biopsies showed destruction of kidney tubules and liver parenchyma by apoptosis. The toxic agen was identified as atractyloside by liquid chromatography coupled mass spectrometry. This substance is known to interfere with ATP synthesis by inhibition of which of the following mitochondrial proteins?

Answer 20

ATP/ADP exchanger

Question 21

A good reducing agent is one that:

Answer 21

readily donates electrons

Question 22

If 2 molecules of FADH2 and 6 molecules of NADH enter into ETC, how many units of ATP will be formed?

Answer 22

18
FADH2-> 1.5 ATP (2 ATP)
NADH-> 2.5 ATP (3 ATP)

Question 23

In a test tube, you combine a preparation of mitochondria from rat liver, 10 units of NADH, 6 units of FADH2, and a saturating amount of rotenone. How many ATP units will be formed in the test tube?

Answer 23

rotenone inhibits Complex I; 6 ATPx 1.5 ATP= 9 ATP

Question 24

The inhibitor rotenone blocks transfer of electrons from Fe-S protein in Complex I to CoQ. Which of the following processes would most likely be lessened as well?

Answer 24

reduction of oxygen by Complex IV; the reduction of O2 by complex IV would be most likely to be limited by the inhibitor. FADH2 can still enter at Complex II

Question 25

Based upon your knowledge gained from MCM lectures, which of the following would you expect to occur as ADP levels rise in the mitochondria?

Answer 25

ATP synthase activity would increase

Question 26

which of the following most likely occur if the mitochondrial inner membrane was freely permeable to small ions?

Answer 26

electron transport would be uncoupled from ATP synthesis; proton gradient would collapse and the chemiosmotic synthesis of ATP would cease