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ENZYMES- Part 7
See all quizzes of ENZYMES- Part 7 here:
1 In β-oxidation 3-ketoacyl-CoA is splitted
at the 2, 3 position by the enzyme:
(A) Hydratase (B) Dehydrogenase
(C) Reducatse (D) Thiolase
2. Fatty acids with odd number of carbon
atoms yield acetyl-CoA and a molecule of
(A) Succinyl-CoA (B) Propionyl-CoA
(C) Malonyl-CoA (D) Acetoacetyl-CoA
3 For each of the first 7-acetyl-CoA molecules
formed by α-oxidation of palmitic acid,
the yield of high energy phosphates is
(A) 12 (B) 24
(C) 30 (D) 35
4. The net gain of ATP/mol of palmitic acid
on complete oxidation is
(A) 88 (B) 105
(C) 129 (D) 135
5. ω-oxidation is normally a very minor
pathway and is brought by hydroxylase
enzymes involving
(A) Cytochrome a (B) Cytochrome b
(C) Cytochrome c (D) Cytochrome p-450
6. α-Oxidation i.e., the removal of one
carbon at a time from the carboxyl end
of the molecule has been detected in
(A) Brain tissue (B) Liver
(C) Adipose tissue (D) Intestine
7. In β-oxidation, the coenzyme for acyl-CoA
dehydrogenase is
(A) FMN (B) NAD
(C) NADP (D) FAD
8. The coenzyme involved in dehydrogenation
of 3-hydroxy acyl-CoA is
(A) FAD (B) FMN
(C) NAD (D) NADP
9. The concentration of ketone bodies in the
blood does not normally exceed
(A) 0.2 mmol/L (B) 0.4 mmol/L
(C) 1 mmol/L (D) 2 mmol/L
10. In humans under normal conditions loss
of ketone bodies via urine is usually less
than
(A) 1 mg/24 hr (B) 4 mg/24 hr
(C) 8 mg/24 hr (D) 10 mg/24 hr
11. The structure which appears to be the only
organ to add significant quantities of
ketone bodies to the blood is
(A) Brain (B) Erythrocytes
(C) Liver (D) Skeletal muscle
12. The starting material for ketogenesis is
(A) Acyl-CoA (B) Acetyl-CoA
(C) Acetoacetyl-CoA (D) Malonyl-CoA
13. Enzymes responsible for ketone body
formation are associated mainly with the
(A) Mitochondria
(B) Endoplasmic reticulum
(C) Nucleus
(D) Golgi apparatus
14. The synthesis of 3-hydroxy-3-methylglutaryl-
CoA can occur
(A) Only in mitochondria of all mammalian tissues
(B) Only in the cytosol of all mammalian tissue
(C) In both cytosol and mitochondria
(D) In lysosomes
15. In the pathway leading to biosynthesis
of acetoacetate from acetyl-CoA in liver,
the immediate precursor of aceotacetate
is
(A) Acetoacetyl-CoA
(B) 3-Hydroxybutyryl-CoA
(C) 3-Hydroxy-3-methyl-glutaryl-CoA
(D) 3-Hydroxybutyrate
16. Ketone bodies serve as a fuel for
(A) Extrahepatic tissues
(B) Hepatic tissues
(C) Erythrocytes
(D) Mitochondria
17. In extra hepatic tissues, one mechanism
for utilization of acetoacetate involves
(A) Malonyl-CoA (B) Succinyl-CoA
(C) Propionyl-CoA (D) Acetyl-CoA
18. Ketosis reflects
(A) Increased hepatic glucose liberation
(B) Increased fatty acid oxidation
(C) Increased carbohydrate utilisation
(D) Incresed gluconeogenesis
19. Ketosis is associated with the disease:
(A) Nephritis
(B) Diabetes mellitus
(C) Edema
(D) Coronary artery diseases
20. The main pathway for denovo synthesis
of fatty acids occur in
(A) Cytosol (B) Mitochondria
(C) Microsomes (D) Nucleus
21. Chain elongation of fatty acids in
mammalian liver occurs in
(A) Nucleus (B) Ribosomes
(C) Lysosomes (D) Microsomes
22. Acetyl-CoA is the principal building block
of fatty acids. It is produced within the
mitochondria and does not diffuse readily
into cytosol. The availability of acetyl CoA
involves
(A) Carnitine acyl transferase
(B) Pyruvate dehydrogenase
(C) Citrate lyase
(D) Thiolase
23. The synthesis of fatty acids is often termed
reductive synthesis.
(A) NADP+ (B) NADH
(C) FADH2 (D) NADPH
24. The protein, which is in fact a multifunctional
enzyme complex in higher organism
is
(A) Acetyl transacylase
(B) Malonyl transacylase
(C) 3-Hydroxy acyl-ACP dehyratase
(D) Fatty acid synthase
25. The fatty acid synthase complex catalyses
(A) 4 sequential enzymatic steps
(B) 6 sequential enzymatic steps
(C) 7 sequential enzymatic steps
(D) 8 sequential enzymatic steps
26. The main source of reducing equivalents
(NADPH) for lipogenesis is
(A) Pentose phosphate pathway
(B) Citric acid cycle
(C) Glycolysis
(D) Glycogenolysis
27. In fatty acids synthase of both bacteria
and mammals, ACP (acyl carrier protein)
contain the vitamin:
(A) Thiamin (B) Pyridoxine
(C) Riboflavin (D) Pantothenic acid
8. Carboxylation of acetyl-CoA to malonyl-
CoA requires the enzyme:
(A) Acetyl-CoA carboxylase
(B) Pyruvate carboxylase
(C) Acetyl transacylase
(D) Acyl CoA-synthetase
29. The rate limiting reaction in the lipogenic
pathway is
(A) Acetyl-CoA carboxylase step
(B) Ketoacyl synthase step
(C) Ketoacyl reductase step
(D) Hydratase step
30. Conversion of fatty acyl-CoA to an acyl-
CoA derivative having 2 more carbon
atoms involves as acetyl donar:
(A) Acetyl-CoA (B) Succinyl-CoA
(C) Propionyl-CoA (D) Malonyl-CoA
