Biochemistry Final
1)Enzyme involved in test examination of Beri-beri which is caused
by severe deficiency in thiamine :
a)Glucose 6 phosphate dehydrogenase
b)Transaldolase
c)Pyruvate carboxylase
d)Glucokinase
ANS : b
2)The good, the bad and the ugly diet which is contraindicated is :
a)Semi-starvation
b)High protein
c)High carbs low fat
d)High fat Low carbs
ANS: d
3)Why do Jordanians eat knafeh after mansaf:
ANS: Fats burn in the fire of carbohydrates.
4)Why do we gain weight in winter(Choose all the correct answers)
A.We exercise less
B.We eat more carbs for energy
ANS: A,B
4)Enzyme when inhibited have both antitumor and anti-obesity
effects :
a)Thiolase
b)Malonyltransferase
c)Fatty acid synthase
ANS: c
5) A person on a fat free carbohydrate rich diet continues to grow
obese. Which of the following lipoproteins is likely to be elevated in
his blood?
a) Chylomicrons
b) VLDL
c) LDL
d) HDL
ANS: b
6)Lipoproteins consist of :
a)A hydrophilic core of triglycerides and cholesterol esters
b)Hydrophbic core of triglycerides and cholesterol esters
c)hydrophobic core of phospholipids and apoproteins
d)Hydrophobic core of triglycerides and free cholesterol
ANS: b
7)Amino acid not involved in glutathione synthesis :
a)cysteine
b)glycine
c)glutamine
d)serine
ANS: d
8)Most abundant phospholipids in humans (It’s a combination
question so choose 2) :
A.Phosphatidylcholine
B.Phosphatidylserine
C.Phosphatidylethanolamine
D.Phosphatidylinositol
ANS: a&c
9)The enzyme which is located in the inner mitochondrial membrane
and in involved in ETC is :
a)Succinyl coa synthetase
b)Succinate dehydrogenase
c)Alpha-Ketoglutarate dehydrogenase
d)Aconitase
ANS: b
10)The link between carbohydrates metabolism and amino acids
metabolism is :
a)Transamination
b)Carboxylation
c)Decarboxylation
ANS: a
11)Drug approved for long-term use for weight loss :
a) Zyban
b)Leptin
c)Xenical
d)Topimax
ANS: c
12)Products of tryptophan degradation (A combination question,
choose 2):
A.Fumarate
B.Acetoacetate
C.Alanine
D.Cysteine
ANS: B&C
13)True about ascorbic acid(A combination question choose all the
correct answers)
A. Involved in Oxidation-Reduction reactions
B. Cofactor in the synthesis of norepinephrine
C. Aids in the metabolism of tryptophan
D. Involved in the synthesis of lipids and proteins
ANS: A,B & C
14) Which of these vitamins’ deficiency would cause pellagra:
a)Thiamine
b)Riboflavin
c)Niacin
d)Pyridoxine
ANS: c
15) Which of the following is an indicator of liver disease when
elevated in plasma:
ANS: Alanine transaminase
16)Based on your study of urea cycle; which of the following
statements regarding its products is correct:
a)one molecule aspartic aicd , one molecule of ammonia ,one
molecule of ATP and one molecule of fumaric acid.
b)One molecule of urea, one molecule ammonia , one molecule of
ATP and one molecule of fumaric acid.
c)One molecule urea ,one molecule of AMP ,two molecules of
ADP and one molecule of fumarate
ANS: c
17)Carbamoyl phosphate synthetas-1 is regulated by :
a)Allosteric activation by N-acetylglutamate
b) Allosteric inhibition by AMP
c)Allosteric inhibition by fumarate
d)Allosteric inhibition by urea
ANS: a
18) Starting with the ornithine transcarbamoylase reaction , the order
in which intermediates in the urea cycle would occur is:
a)Argininosuccinate –Citrulline-Arginine- Ornithine
b)Citrulline- Arginine-Ornithine-Argininosucinate
c)Citrulline-Argininosuccinate-Arginine- Ornithine
d) Citrulline-Arginine- Argininosuccinate-Ornithine
ANS: c
19)Functions as the body’s internal transport mechanism for lipids<
assembled in the liver from TGs, cholesterols and apolipoproteins, its
density ranges between 0.95-1.006 and the mean diameter lies
between 30-80 nm; the previous description best defines :
a)VLDL
b)LDL
c)IDL
d)CM
ANS: a
20) A patient presented with very high levels of serum cholesterol.
After a series of tests it was concluded that he has high circulating
levels of LDL cholesterol but has normal levels of the liver LDL
receptor, this is best explained by :
a) The absence of the enzyme lipoprotein lipase
b) Mutated form of apoprotein B100
c) The inability to selectively remove cholesterol from LDL
complex
d)Altered phosphorylation of the LDL receptor
ANS: b
21)Which of the follow enzymes requires ATP to mediate its
reactions:
a)Ariginosuccinate lyase
b)Arginase
c)Ornithine transcarbamylase
d)Carbamoyl phosphate synthetase 1
ANS : d
22)In winter , people in Jordan usually die from:
a) CO2
b)Car accidents
c)CO
b) Ni
ANS: c
23) A 41 years old man , has atherosclerotic plaques , he has high
cholesterol and LDL levels, which of the following is digested to
LDL:
a)Choelsterol
b)hollesterol esters
c)HDL
d)IDL
ANS: d
24) The major TGs carriers are :
a)VLDL&CM
b)LDL&IDL
c)IDL&VLDL
d)CM&LDL
ANS: a
25)Which is correct about vitamin B12 (Choose all the correct
answers)
A.Fat soluble vitamin
B.Water soluble vitamin
C.Deficiency causes aplastic anemia
D.cofactor for methylmalonyl-CoA mutase activity
ANS: B&D
26) A protein present in brown adipose tissue:
a)UCP-1
b)UCP-2
c)UCP-5
d)UCP-4
ANS: a
27)What’s common between ketone bodies formation and cholesterol.
Synthesis (Choose all the correct answers):
A.Both occur in the mitochondria
B.Uses acetyl CoA as a carbon source
C.HMG CoA is a common intermediate
ANS: B&C
28)HMG-CoA Reductase is inhibited by:
a)HMG-CoA
b)Cholesterol
c)Acetyl coa
d)ATP
ANS: b
29)The product of methionine metabolism :
a)Cystine
b)Cysteine
c)Homocysteine
ANS: b
30)Glucose-6-phosphate is an intermediate in which of these
pathways (Choose all the correct answers)
A.PPP
B.Gluconeogenesis
C.Glycolysis
D.Glycogenolysis
ANS: All answers are correct
31) In Tay-sach’s disease which of the following accumulates:
a)Sphingolipids
b)Glycogen
c)Gangliosides
d)Glucose
ANS: c
32) The characteristics of the new food pyramid (Choose all the
correct answers):
A. Restrict sugar and butter
B.Drink 6-8 cups of water
C. Restrict meats and nuts.
D. Daily exercise
ANS: A,B & D
33)A glycogen storage disease characterized by long unbranched
glucose chains stored in glycogen, the deficiency is in which of the
following enzymes:
a)Glycogen branching enzyme
b)Glycogen debranching enzyme
c)Glucose-6-phosphatase
d)Liver phosphorylase system
ANS: a
34)In case of starvation for 2 weeks, which of these is the main source
of energy :
a)Glycogen
b)proteins
c)Cholesterol
d)Triacylglycerides
ANS: d
35)What is correct about vitamin K (choose all the correct answers):
A. Cofactor of liver microsomal carboxylase
B. Synthesis of prothrombin
C. Synthesis of coagulation factors XI,VIII and X
D. Forms the binding site for Na+ on osteocalcin
ANS: A & B
36) Oxaloacetate can’t give which of these amino acids :
a)Methionine
b)Isoleucine
c)Pyruvate
b)Threonine
c)Lysine
ANS: c
37)After careful reading of the following sentences , choose the most
correct combination :
A.F.As are oxidized by all tissues in the body.
B.The rate of beta-oxidation is regulated by 2 mechanisms, the
availability of F.As and the rate of utilization of beta-oxidation
productions
C.The availability of F.As is dictated by the insulin-glucagon ratio,
when it’s high it stimulates the breakdown of adipose tissue
triglycerides and therefore the release of NEFAs
D.In beta-oxidation , F.As are degraded by the sequential
liberation of acetyl CoA units, this occurs primarily in the
mitochondria.
ANS: B&D
