biochem oxidative phos. Flashcards
which of the following is not true about Coenzyme Q
it is lipid soluble
it is found in the inner mitochondrial membrane
it contains one Fe atom which can carry one electron
the electron-rich form is ubiquinol
it contains one Fe atom which can carry one electron
which of the following is not true
all cytochromes contain one Fe atom which can carry one electron
Class a cyt’s, are integral membrane proteins
Cyt. c is an integral membrane protein
Cyt. c is an integral membrane protein
Where in the mitochondria are the electron transport complexes found?
A. Outer membrane
B. Inter-membrane space
C. Inner membrane
D. Matrix
C. Inner membrane
is oxidized by Complex I, ___ is oxidized by Complex II
A. Cytochrome c, cytochrome a
B. NADH, FADH2
C. NAD+, FAD
D. Q, Q
B. NADH, FADH2
what molecule transports electrons from complex I to complex II
Coenzyme Q
Cytochrome c
FAD
NAD
none of the above
none of the above
for every cycle of beta oxidation, how many protons are pumped through complex II
0
2
4
6
0
what does the M.A shuttle do
transports NADH into mitochondria matrix
transports NADH out of mitochondria matrix
transports reducing electrons into mitochondria matrix
transports reducing electrons out of mitochondria matrix
transports reducing electrons into mitochondria matrix
What molecule transports electrons from complex I/II to Complex III?
A. Cytochrome c
B. FAD
C. FMN
D. NAD+
E. CoenzymeQ
E. CoenzymeQ
what molecule transports electrons from complex III to complex IV
NADH
ubiquinol
FADH2
cytochrome c
cytochrome c1
cytochrome c
what molecule is reduced by (receives) eletrocn from complex IV
NADH
succinate
coenzyme Q
cytochrome c
O2
O2
For every pair of electrons that pass through Complex I-IV of the electron transport chain, how many protons are pumped from the matrix to the inter-membrane space?
A. 4, 0, 4, 2
B. 4,0,2,4
C. 4, 2, 0, 2
D. 2,4,0,4
E. 2,0,4,2
A. 4, 0, 4, 2
what is the primary regulator of oxidative phosphorylation
acetyl-CoA
ATP
ADP
Citrate
NADH
ADP
oligomycin directly inhibits
complex I
complex II
complex III
complex IV
ATP synthase
ATP synthase
which of the following is an uncoupler of oxidative phosphorylation
antimycin A
carbon monoxide
cyanide
DNP
rotenone
DNP
If antimycin A is added to properly functioning mitochondria, which of the following will not be true?
A. [NADH]/[NAD+] ratio will increase
B. O2 consumption will increase
C. Oxidative phosphorylation will slow or stop
D. Electron transfer will slow or stop
B. O2 consumption will increase
in normally functioning mitochondria, which of the following would be most likely to increase the rate of NADH consumption (oxidation)
adding an uncoupler to the mix
adding cyanide to the mix
adding antimycin A to the mix
increasing the [ATP]/[ADP] ratio in the mitochondria
adding an uncoupler to the mix
if DNP is added to properly functioning mitochondria, which of the following will be true
the [NADH]/[NAD+] ratio will increase
oxygen (O2) consumption will be reduced
oxidative phosphorylation will take place as usual
electron transfer will take place as usual
none of the above
electron transfer will take place as usual
experimental analysis
1 - if intact mitochondria are incubated with ADP, Pi, NADH, succinate and O2 the concentrations of all these compounds begin to decrease while the concentrations of ATP, NAD, and fumarate begin to increase
2 - then if MM1 is added to the mixture, the rates of consumption of ADP, Pi & O2 decrease and the rate of formation of ATP decreases, NADH is no longer consumed and the rate of consumption of succinate is unchanged
1 - it blocks complex I
2 - it blocks complex II
3 - it blocks complex III
4 - it blocks ATP synthase
5 - it is an uncoupler
1 - it blocks complex I
What is the “energy cost” of forming malonyl- CoA from acetyl-CoA?
A. 1 ATP
B. 1 FADH2
C. 1 NADH
D. 1 NADPH
A. 1 ATP
What is the primary source of reducing electrons for fatty acid biosynthesis?
A. FADH2
B. NADH
C. NADPH
D. ATP
the NADPH required for F.A synthesis can be formed when ___ is oxidized
acetyl CoA
citrate
malate
oxaloacetate
pyruvate
malate
How does acetyl-CoA for FA synthesis get from the mitochondria to the cytosol?
A. Through an acetyl-CoA transporter
B. Through the malate-aspartate shuttle
C. As a part of oxaloacetate
D. As a part of citrate
D. As a part of citrate
the first step in TAG synthesis is the formation of ___ the second step in TAG synthesis is the formation of ____
acetyl CoA
glycerol 3-phos., phosphatidic acid
linoleic acid, arachidonate
glycerol, diacylglycerol
linoleic acid, arachidonate
What enzyme is regulated to control the rate of glyceroneogenesis?
glycerol 3-phosphate dehydrogenase
pyruvate dehydrogenase
pyruvate carboxylase
PEP carboxykinase (PEPCK)
PEP carboxykinase (PEPCK)
What effect does cortisol have on the rate of TAG synthesis in adipose
it increases the rate
it decreases the rate
it decreases the rate
what effect does cortisol have on the rate of TAG synthesis in the liver
it increases the rate
it decreases the rate
it increases the rate
how does cortisol affect the rates of TAG synthesis
allosteric regulation
covalent regulation
regulation of gene expression
regulation of gene expression
what effect do the thiazolidinediones have on glyceroneogenesis
decrease In adipose
increase in adipose
decrease in liver
increase in liver
increase in adipose
____is an omega-3 fatty and and ____is a precursor of arachidonic acd
DHA, linolenate
DHA, EPA
EPA, linolenate
linolenate, linolenate
linolenate, linolenate
Steroidal Anti-Inflammatory Drugs Inhibit…
A. COX-1 only
B. COX-2 only
C. Both COX enzymes
D. Release of arachidonate from cell membranes
D. Release of arachidonate from cell membranes
what enzyme do aspirin and other NSAIDS inhibit
fatty acid synthase
magic enzyme
cyclooxygenase
citrate lyase
PEP carboxykinase
cyclooxygenase
COX-2 is part of the pathway leading to the synthesis of compounds involved in
platelet aggregation (thromboxjnes)
stomach protection (mucins)
causing pain and inflammation
causing pain and inflammation
The enzyme that catalyzes the rate-limiting step in cholesterol synthesis is…
A. COX
B. Citrate lyase
C. HMG-CoA reductase
D. PEP carboxykinase
E. Pyruvate dehydrogenase
C. HMG-CoA reductase
which of the following would promote the activity of HMG-CoA reductase
elevated [insulin]
elevated [glucagon]
elevated intracellular [cholesterol]
elevated [insulin]
HMG-CoA reductase is competitively inhibited by
corticosteroid
NSAIDs
statins
thiazolidinediones
uncouplers
statins
PCSK9
brings more LDL receptors to the surface of cells
inhibits the receptor-mediated and endocytosis of cholesterol
prevents LDL receptors from returning to the cell surface
prevents LDL receptors from returning to the cell surface
cholesterol is a precursor for the biosynthesis
bile acids
cholesterol esters
vitamin A
vitamin D
steroid hormones
vitamin A
