MCQ on Fatty Acid Synthesis and Breakdown (beta-oxidation) is available for you for free on Medicalfond with other related mcq on biochemistry
1) Free fatty acids in the plasma
a) Circulate in the unbound state
b) Bind to lipoproteins and
circulated
c) Bind to albumin and circulated
d) Bind to a fatty acid-binding
protein and circulated
2) In what compartment does the de
novo fatty acid synthesis occur?
a) Mitochondria
b) Peroxisome
c) Endoplasmic reticulum
d) Cytosol
3) What is the precursor for fatty
acid synthesis?
a) Acetyl CoA
b) Propionyl CoA
c) Succinyl CoA
d) Acetoacetyl CoA
4) The conversion of acetyl CoA to
malonyl CoA is the rate-limiting step in the fatty acid synthesis.
Which of the following enzyme
catalyzes the above-mentioned reaction?
a) Acetyl CoA carboxylase
b) Malonyl CoA synthetase
c) Acetyl CoA decarboxylase
d) Malonyl CoA synthase
5) The acetyl CoA is produced in the
mitochondria and must be transported into the cytosol for the synthesis of
fatty acid.
Which of the following is true
regarding the transport of Acetyl CoA?
a) Acetyl CoA is diffused from the
mitochondrial membrane
b) Acetyl CoA is transported by its
specific transporter protein
c) Acetyl CoA is converted into
pyruvate, enters into the cytosol and acetyl CoA is regenerated
d) Acetyl CoA is converted into
citrate, enters into the cytosol and acetyl CoA is regenerated.
6) What is the allosteric regulator
of acetyl CoA carboxylase?
a) Fatty acid
b) ATP
c) Citrate
d) Acetyl CoA
7) Which of the following event
inactivates acetyl CoA carboxylase?
a) ADP-Ribosylation
b) Glycosylation
c) Phosphorylation
d) Farnesylation
8) Which of the following is not a
positive regulator of acetyl CoA carboxylase?
a) Excess calories
b) Insulin
c) Citrate
d) Long-chain fatty acid
9) Which of the following enzyme statement
is not true regarding fatty acid synthase?
a) Fatty acid synthase is a
multifunctional enzyme
b) Fatty acid synthase is active as
a dimer
c) Fatty acid synthase is activated
by high-calorie food
d) Fatty acid synthase complex is
inhibited by its phosphorylation
10) What form of energy is required
for fatty acid biosynthesis?
a) ATP
b) NADH
c) NADPH
d) FADH2
11) What is the source of NADPH
required for fatty acid synthesis?
a) Pentose phosphate pathway
b) Malic enzyme
c) Both
d) None
12) What is the fate of fatty acid
entering the cells?
a) Fatty acid diffuses into
mitochondria for beta-oxidation
b) Fatty acid is converted into
fatty acyl CoA (activated form)
c) Fatty acid is bound to albumin in
the cytosol
d) None of the above
13)What is the role of L-carnitine
in fatty acid metabolism?
a) Facilitate the transport of fatty
acid from the cytosol to mitochondria
b) Serve as a cofactor for enzyme
fatty acid synthase
c) Activator of acetyl CoA
carboxylase
d) None of the above
14) Identify the correct sequential
enzymatic step for fatty acid synthesis:
a) Delta-2-enoyl CoA Dehydrate, Acyl
CoA Dehydrogenase, Hydroxy acyl dehydrogenase, Thiolase
b) Hydroxy acyl dehydrogenase, Acyl
CoA Dehydrogenase, Delta-2-enoyl CoA Dehydrate, Thiolase
c) Thiolase, Acyl CoA Dehydrogenase,
Delta-2-enoyl CoA Dehydrate, Hydroxy acyl dehydrogenase
d) Acyl CoA Dehydrogenase,
delta-2-enoyl CoA Dehydrate, Hydroxy acyl dehydrogenase, Thiolase
15) The complete beta-oxidation of
palmitoyl CoA yield
a) 8 molecules of Acetyl CoA and 16 NADH
b) 8 molecules of Acetyl CoA and 16
FADH2
c) 8 molecules of Acetyl CoA, 8
NADH, and 8 FADH
d) 8 molecules of Acetyl CoA and 16
NADPH
16) High rate of beta-oxidation in
the liver leads to ketogenesis (ketone body synthesis).
Which of the following condition may
result in ketogenesis?
a) Uncontrolled Type I diabetes
b) Pregnancy
c) Starvation
d) All of the above
17) Which of the following step is
unique to the formation of ketone bodies?
a) Formation of Acetoacetyl CoA
catalyzed by thiolase
b) Formation HMG CoA catalyzed by
HMG CoA synthase
c) Splitting of HMG CoA to acetyl
CoA and acetoacetate catalyzed by HMG CoA lyase
d) Reduction of acetoacetate to
3-hydroxybutyrate catalyzed by 3-hydroxybutyrate dehydrogenase
18) Identify the key regulators of
the ketogenic pathway:
a) Acyl CoA/CoA ratio
b) NADH/NAD ratio
c) Insulin/Glucagon ratio
d) All of the above
19) Dicarboxylic aciduria is
characterized by the excretion of C6–C10 ω-dicarboxylic acids and by nonketotic
hypoglycemia.
Identify the defective enzyme from
the following?
a) Long Chain Acyl CoA Dehydrogenase
b) Medium Chain Acyl CoA
Dehydrogenase
c) Short Chain Acyl CoA
Dehydrogenase
d) Very Long Chain Acyl CoA
Dehydrogenase
20) Which of the following is the
rate-limiting step of fatty acid oxidation and is also inhibited by malonyl
CoA?
a) Thiokinase
b) Carnitine Palmitoyl transferase I
c) Acyl CoA Dehydrogenase
d) Thiolase
Multiple Choice Answer Reviews:
1-c) Bind to albumin and circulated
2-d) Cytosol
3-a) Acetyl CoA
4-a) Acetyl CoA carboxylase
5-d) Acetyl CoA is converted into
citrate, enters into the cytosol and acetyl CoA is regenerated.
6-c) Citrate
7-c) Phosphorylation
8-d) Long-chain fatty acid
9-d) Fatty acid synthase complex is
inhibited by its phosphorylation
10-c) NADPH
11-c) Both
12-b) Fatty acid is converted into
fatty acyl CoA (activated form)
13-a) Facilitate the transport of
fatty acid from the cytosol to mitochondria
14-d) Acyl CoA Dehydrogenase,
delta-2-enoyl CoA Dehydrate, Hydroxy acyl dehydrogenase, Thiolase
15-c) 8 molecules of Acetyl CoA, 8
NADH, and 8 FADH
16-d) All of the above
17- Option c) and d)
18-d) All of the above
19-b) Medium Chain Acyl CoA
Dehydrogenase
20-b) Carnitine Palmitoyl
transferase