Electron Transport Chain Flashcards
Muscle contraction causes an immediate increase in the rate of oxidative phosphorylation. Which statement BEST explain the effect of contraction?
A. It increases the pH.
B. It increases the NAD+ concentration.
C. It increases the activity of phosphofructokinase.
D. It increases the ADP concentration.
A
When oxidative phosphorylation is uncoupled by dinitrophenol, which one of the following actions takes place?
A. Phosphorylation of adenosine diphosphate (ADP) accelerates.
B. ATP production continues but oxygen uptake stops.
C. ATP production stops but oxygen uptake continues.
D. Both phosphorylation of ADP and oxygen uptake stop.
C
The major production of ATP during aerobic metabolism occurs when electrons from _____ and _____ are transferred to _______. Choose the best answer from the items below.
A. FADH2 + NADH -→ H2 0
B. FADH2 + O2 -→ NAOH
C. NADH + O2 -→ FADH2
D. FADH2 and NADH -→ O2
D
ATP synthase can produce ATP using which of the following as a direct energy source?
A. Energy from conversion of glucose to pyruvate.
B. Energy from the oxidation of pyruvate producing CO2 and H2O.
C. Energy from a proton gradient established in mitochondria.
D. Energy derived from the breakdown of NADH and FADH2.
C
During a heart attack, blood flowing to the heart muscle is interrupted by blockage of a coronary artery. How would you expect the metabolism in the heart to change?
A. Oxidative phosphorylation would slow down in the mitochondria.
B. The rate of production of lactic acid would be stimulated.
C. The use of glucose by the muscle tissue would increase.
D. All of the above
D
What cellular compartment becomes acidic (high concentration of hydrogen ions) during mitochondrial electron transport?
A. Mitochondrial stroma
B. Cytoplasm
C. Endoplasmic reticulum
D. Space between inner and outer mitochondrial membrane
D
Which of the following enzymes utilizes molecular oxygen as an electron acceptor?
A. Catalase
B. Cytochrome c oxidase
C. Glutathione peroxidase
D. Superoxide dismutase
B
Mechanism of fluoracetate?
A. binds na competitive inhibition w/ citrate cyntax
B. forms fluorocitrate and binding with acomtas
C. Directly inhibits citrate synthase
D. directly inhibits comple I of the ETC
B
Below is the overall reactive catalyzed by the complex I of
the ETC
NADH + ubiquinone NAD + ubiquinol
What is the other name of complex I?
A. NADH – Co G reductase
B. CoQ – cyto C reductase
C. succinate – Co Q reductase
D. cyt AA3 reductase
A
What is the cofactor of complex I?
A. NAD +
B. FMN + FeS
C. FC-S + Cu
B
Match the compound with its corresponding rates in the electron transport chain
Inhibits ADP transport into mitochondria
A. DNP B. iron-porphyrin compound C. oligomycin D. atractyloside E. carbon monoxide
D
Match the compound with its corresponding rates in the electron transport chain site specific inhibitor of ETC
Site specific inhibitor of ETC
A. DNP B. iron-porphyrin compound C. oligomycin D. atractyloside E. carbon monoxide
E
Match the compound with its corresponding rates in the electron transport chain
Inhibitor of ATP synthetase
A. DNP B. iron-porphyrin compound C. oligomycin D. atractyloside E. carbon monoxide
C
Match the compound with its corresponding rates in the electron transport chain
An uncoupler
A. DNP B. iron-porphyrin compound C. oligomycin D. atractyloside E. carbon monoxide
A
Which of the following is correct?
A. carbonic anhydrase is a hydrolase
B. catalase is a hydrolase
C.Tissue plasminogen is a hydrolase
D. carbonic anhydrase is a carboxylase
C
Which of the following statements is correct?
A. pyridoxal phosphate serves as co-enzyme for methyltransferases
B. S-adenosyl methionine serves as co-enzyme for aminotransferases
C. certain inorganic cations are coenzymes
D. apoenzymes consists purely of proteins
D
What is the difference in fucntion of NAD(H) and NADP(H)?
Generally, NAD(H) carries electrons from catabolic reactions, NADP(H) carries electrons to anabolic reactions
How do cells mantain separate pools of NADPH and NADH?
Cells hold the ratio of [reduced form]/oxidized form] relatively high for NADPH and relatively low for NADH
What are the five types of electron-carrying molecules that function in the respiratory chain?
NAD, flavoproteins, ubiquinone (or coenzyme Q), cytochromes and iron-sulfur proteins
The two forms of ubiquinone
QH and QH2
Ubiquinone is small and hydrophobic. T/F
T
Why is ubiquinone diffusible within the lipid bilayer of the inner mitochondrial membrane?
Because it is small and hydrophobic
Proteins with characteristic strong absorption of visible light, due to their iron-containing heme prosthetic groups
Cytochrome
What are the three classes of cytochromes in the mitochondria?
Cytochromes a, b, and c
Electron carriers in the ETC function in order of decreasing reduction potential. T/F
F
They function in order of increasing reduction potential, because electrons tend to flow spontaneously from carriers of lower E’° to carriers of higher E’°
Complex I of the mitochondrial respiratory chain catalyzes twi simultaneous and obligately coupled process. What are these processes?
(1) transfer to ubiquinone of a hydride ion from NADH and a proton from the matrix
(2) transfer of four protons form the matrix to the intermembrane space
NADH dehydrogenase is which protein complex in the ETC?
Complex I
Complex II can be found in which other metabolic process?
TCA
Complex II in the TCA is known as what?
Succinate dehydrogenase
Complex II makes use of which electron carrier?
FAD(H2)
