1-
What is the reason of sickle cell anemia?
A.
substitution of Val with Glu in beta-chain of
hemoglobin
B.
substitution of Lent with ILe in
beta-chain of hemoglobin
C. substitution of Glu with Val in beta-chain of
hemoglobin
D. substitution of Phe with
Gln in beta-chain of hemoglobin
2- what is not correct
answer for hemoglobin and myoglobin ?
A.
myoglobin has low
affinity to oxygen than hemoglobin
B.
myoglobin has one site to bind oxygen
C.
Low pH decrece the
affinity of hemoglobin to oxygen
D.
myoglobin has
one polipeptide chain
3- alanin is similar
to serine in the same way that ?
A. Val is similar to thr
B. Phe is similar to tyr
C. Phe is similar to trp
D. Ser is similar to thr
4- Which one describes an allosteric interaction between a ligand and
a protein?
A.
binding of a molecule to a binding
site affects binding of additional molecules to the same site.
B.
binding of a
molecule to a binding site affects binding properties of another site on the
protein.
C.
binding of the ligand to the
protein is covalent.
D.
two different ligands can bind to
the same binding site.
5- which of the flowing
amino acid sequence is most likely to be found
in membrane embedded protein of a protein ?
A.
Val-Ile-Leu-Ala-Pro-Ala-Gly
B. Ser-Asp-Glu-Gln-Asn-Trp-Asp
C. His-Len-Asp-Asp-Glu-Tyr
D.
His-Lys-Pro-Lys-Arg-Gln
6- assuming that the
pressure of oxygen (mm hg) stay constant
, the right shift of the hemoglobin-O2
dissociation curve result in the following changes of O2 saturation and affinity of
oxygen for hemoglobin
A. Increase
decrease
B. Decrease
no change
C. Decrease decrease
D.
Increase increase
7- alanin is similar to serine in the same way
that ?
A. Val is similar to thr
B.
Phe is similar to tyr
C. Phe is similar to trp
D. Ser is similar to thr
8- ascórbico acid playas an
importante role in which amino acid modification of colagen
A. Activation of certain lysines th active aldehydes via lysine oxidine
B. Hydroxilation of certain proline and lysine
reoxidaes via spesific hydroxylases
C. Formation of disulfide bridge to place collagen chain in the proper
register for hélix formation
D. Glycosilation of hydroxylysn i son theri-OH group
9- What factor increases the affinity of
hemoglobin to oxygen?
A.
high concentration of oxygen
B.
high
concentration 2,3 BPG
C.
low pH
D.
high
concentration of CO2
10- Which of the following is correct concerning
deoxihemoglobin?
A.
It is R form of Hb
B.
It is weaker acid
compared to oxihemoglobin
C.
The 6th coordinative bond in the molecule is
occupied
D.
iron atom is in the state Fe3+
11-which of the following is correct regarding the
structure of Mb and Hb
A.
H bis an alpha2 beta2 tetramer, meaning that A
subunit are primarily alpha-helical,whereas the beta subunit are primarlly beta
–sheet
B. The individual subunit of Hb are similar to
Mb in their tertiary strcture ,although have very dissimilar primary strcture
C.
Hb and Mb are both made up of four different
subunit
D.
Because Hb has foursubunites four differnt iso
12-The pKa for ammonium ion is about 9.4 and
the pH of solution is about 7.4. The
ratio of ammonia to ammonium ion (ammonia/ammonium ion) in solution is about:
A.
\\
1/100
B.
\\\
10/1
C. \\\
1/10000
D.
\\\
100/1
13-the pH of body fluids is stabilized by
buffer systems the compound which will be the most effective at physiologic PH
is
A.
Ha2HPO4 pka =12.32
B.
NH4OH pka =8.24
C.
Citric acid pka =3.09
D. Na2HPO4 pka =7.21
14-for chronic metabolic alkalosis ,effective
compensation by the body involves ?
A.
Expelling H+ in the kidney
B.
Expelling HCO3- in the kidney
C. retaining Co2 in the lung
D.
Expelling OH- in the kidney
15- barbiturates such as amytal disrupt energy
metabolism by blocking the exit of electrons from com.. oxidation of :
a.
CoQH2 .
b. NADH .
c.
FADH2 in
complex II
d.
Cytochrome
c
e.
Cytochrome
c
16-The role of an enzyme in an enzyme-catalyzed
reaction is to:
A.
ensure that the product is more stable than the
substrate.
B.
make the free-energy change for the reaction
more favorable.
C.
increase the
rate at which substrate is converted into product.
D.
ensure that all the substrate is converted to
product.
17- Which of the following statements is not
true about enzymes, as catalysts?
A.
They increase the rate of chemical reaction million
and milliard times
B.
They have high specificity
C. As a rule, they act during high temperature
(100 degree of Celciuse)
D.
The rate of enzymatic reaction is directly
proportional with enzyme concentration
18-Which of the following does not belong to
multienzymatic systems?
A.
Pyruvate dehydrogenase complex
B.
Alpha-ketoglutarate dehydrogenase complex
C.
Glycolytic
enzymatic system
D.
Enzymatic system of respiratory chain
19- Which enzymes’ coenzyme is lipoic acid?
A.
Isocytreate dehydrogenase
B.
Malate dehydrogenase
C.
Citrate synthase
D. Alpha ketoglutarate dehydrogenase
20-The enzymes are inhibited irreversibly by:
A.
proteolytic
cleavage
B.
Modulator protein
C.
Reaction product
D.
Allosteric modification
21-sinthesis of glycogen is inhibited in
hepatocytes in response to stimulation primarly as result of which of the
following
A.
A decrease in the levels phosphorylated
phosphorylase kinase
B.
A decrease in the levels phosphorylated
phosphorylase phosphatase inhibitor-1
C.
A increase in the levels of the dephosphorylated
form of glycogen synthase
D. A increase in the levels of the phosphorylated
form of glycogen synthase
22-Which of the following statements is characteristic
for protein phosphatases?
A.
Protein phosphatases remove phosphate groups
from proteins that have been phosphorylated
B.
Insulin activates protein phosphatases and
removes phosphate groups added by the cAMP cascade
C. The cAMP cascade can inhibit phosphatases
D. \\ It takes a long time for the phosphatases to
reverse the action of the cAMP cascade
23 -Which of the following is the major
messenger in the relaxation process of blood vessels?
A.
DAG
B.
cGMP
C.
cAMP
D.
PIP3
24-What is
thought in the termination mechanism of signal transduction?
A.
increasing the agonist concentration in the
environment
B. Internalization of agonist-receptor complex
C.
Receptor activation
D.
increasing affinity between agonist and
receptor
25- people who suffer from thyroid adenoma have
constitutively activated G protein in the same cell of the thyroid gland tumor
cells not based
on these
b.
26- protein
phosphorylationis commonly involved in which of the following except
A.
Regulation of transcription by
extracellular signal molecules
B.
Activation of protein kinas
molecules
C.
Activation of receptor tyrosine
kinase
D. Activation of G-protein linked
receptore
27- Which of the following statement is true
about G-protein ?
A.
G-protein consist of four protein subunit
B.
G-protein act as first
C.
G-protein
interact with receptor
D.
G-protein bind ADP in the resting state
28- which of the following reaction is
catalyzed by protein kinase ?
A. the phosphorylation of hydroxyl groups in
protein substrates
B.
the hydrolysis of phosphate group in the
protein substrates
C.
the cleavage of blood plasma proteins
D.
the hydrolysis of phosphate group in ATP and GTP
29- Which of the following is correct concerning signal
transdaction
It is the
A
30- the autocrine and paracrine signaling
system has a ………….. signaling distance and ………… duration of response .
A.
Short; long
B.
Long; long
C. Short; short
D.
Long short
31- Which of the following is correct concerning regulation of glycolytic
pathway ?
d
32- Which of the following reactions is
anaplerotic (replenishes intermediate pools) for the citric acid cycle?
A.
Pyruvate +
HCO3+ ATP ----oxaloacetate + ADP + Pi + H+
B.
Oxaloacetate + GTP ---- phosphoenolpyruvate +
CO2 + GDP
C.
Malate + NAD+
---- oxaloacetate + NADH + H+
D.
Oxaloacetate + acetyl-CoA ----citrate + CoA
33-what is not correct concerning starvation state ?
A.
Pyruvate kinase is phosphorylated
B.
Muscle glycogenolysis increases
C.
Gluconeogenic intermediates supplied by
lipolysis
D. Glucose relased into blood by muscle glycogenolysis
34- Which conversion is impossible?
A.
Lactate
---- pyruvate
B.
Pyruvate
---- lactate
C.
Acetyl-CoA
---- pyruvate
D.
Alanine ---- pyruvate
35- A drug is tested in the laboratory and is
found to create holes in both
mitochondrial membranes scientists suspect that the drug will be harmful to
human cells because it will inhibit
A.
Glycolysis.
B.
The citric acid cycle
C.
Oxidative phosphorylation
D.
The citric
acid cycle and oxidative phosphorylation
36- which of the following takes electrons from
FAHD2 ?
A.
NADH-ubiquinone oxidoreductase
B. succinate- ubiquinone oxidoreductase
C.
malate dehydrogenase
D.
cytochrome aa3
37- Insulin activates………..which subsequently
decreases ……level
A.
Protein kinase ;cGMP
B.
Gluconeogenesis ; glucose
C. Phosphodiesterase ;cAMP
D. Glycogenesis
; epinephrine
38- In
the cells stimulated by glucagon, the cAMP initiates an enzymatic cascade that
begins with the activation of protein kinase A (PKA) and whose main results is:
A.
Decreased glycogenolysis and gluconeogenesis increased glycogenesis
and glycolysis
B.
increased glycogenolysis, gluconeogenesis
glycogenesis and glycolysis
C. increased glycogenolysis and
gluconeogenesis Decreased glycogenesis and glycolysis
D.
Decreased glycogenolysis, gluconeogenesis
glycogenesis and glycolysis
39-Which of the following is not involved in steps of
glycolysis between glyceraldehyde 3-phosphate and 3-phosphoglycerate?
A.
catalysis by phosphoglycerate
kinase.
B.
the formation of 1,3-bisphosphoglycerate.
C.
utilization of Pi.
D.
Catalysis by pyruvate kinase
40-
phosphofructokinase-1 (pfk-1) is
anenzyme that regulates the rate glycolysis.which of
the following statement is not characteristic
of this enzyme
A.
pfk-1 is an allostoric enzyme
B.
f2,6 bisp stimulates pfk-1
C. citrate increase the activity
of pfk-1
D.
high levels of ATP increase the Km
for fructose-6-phosphate
41- Which combination of cofactors is involved in the conversion
of pyruvate to acetyl-CoA?
A.
Biotin, FAD, and TPP
B.
NAD+, biotin, and TPP
C.
Pyridoxal phosphate, FAD, and
lipoic acid
D.
TPP, lipoic acid, and NAD+
42-
what is true concerning well-fed state ?
A. pyruvate
kinase , pyruvate dehydrogenase complex acetyl-CoA carboxylase are
dephosphorylated
B.
pyruvate
kinase , pyruvate dehydrogenase complex acetyl-CoA carboxylase are
phosphorylated
C. pyruvate kinase , pyruvate dehydrogenase complex
acetyl-CoA carboxylase are activated
D.
pyruvate
kinase , pyruvate dehydrogenase complex acetyl-CoA carboxylase are
inactivated
43- At the same time that epinephrine activates
the beta receptors it also binds to alpha-1 receptors. Activation of alpha-1 recepore, result which
of the following
A.
\\\ The activation
of glycogen synthase
B.
\\ The activation of glycogen
phosphorylase by cAMP pathway
C.
\\\ The deactivation
of phosphorylase kinase by Ca++-calmodulin
D.
\\\ The activation of phospholipase C and the
production of diacylglycerol
44-\when
pyruvate carboxylase and phosphoenolpyruvate carboxykinase are active, by what
is prevented futile cycling?
A.
\\\
Phosphorylation and activation of pyruvate kinase by insulin via cAMP
B.
\\\
Dephosphorylation and inactivation of protein kinase by glucagon via
cAMP
C.
\\ Phosphorylation and inactivation of pyruvate kinase
by glucagon via cAMP
D. \\\ Phosphorylation and activation of protein
kinase by insulin via cAMP
45- A 13 year-old patient with Type I diabetes
mellitus, home alone, takes an insulin
injection before lunch but then he gets concentrated in a videogame he is
playing and does not eat. Approximately 3 hours later, he becomes sweat, shaky
and confused. These symptoms have appeared as a consequence of:
A.
increased glucagon release from the pancreas
B.
increased insulin release from the pancreas
C.
high sugar levels in blood
D.
low sugar
levels in blood
46-How glucagon and epinephrine provide
hyperglycemia by all of the following except ?
A. \\\ activation of lipogenesis
B. \\\
activation of glycogenesis
C.
\\\
inhibition of gluconeogenesis
D.
\\
activation of gluconeogenesis
47- the binding of hormones to G-protein coupled
receptors stimulation the sequence ( detirmind the correct cods ) 1- binding of Ga (GTP) activates adenylyl cyclase; 2- Ga (GDP) dissociates and re-associates with Gbγ 3- rapid exchange of GDP for GTP on Ga;4 GTPase of Ga hydrolyzes GTP to GDP 5- Ga (GTP) dissociates from Gbγ
A. 3,5,1,4,2
B.
3,5,2,4,1
C.
4,1,3,5,2
D. 5,1,2,4,3
48-if a cell only need to synthesize ribose-5-P
and not NADPH, the enzymes of the hexose monophosphate shunt what of the
following substrates would use from glycolysis?
A.
Fructose-6-phosphate and NADPH
B.
3-phossphoglycerate and Fructose-6-phosphate
C. glyceraldehyde-3-phosphate and
Fructose-6-phosphate
D.
glucose 1 phosphate and lactate
49- A young woman find that every time she eats da
b. beta ( lactase)
50- Mc Ardle's patient
A.
Fail to synthesize glycogen
appropriately
B.
Do not respond to glucagon in a normal fashion
C. Show a produced of glycolysis during
exercise