Which of the following is an example of feedback allosteric inhibition?
پاسخ دهید
(A)
Inhibition of the first enzyme in a pathway by the end product.
2
Reliable marker of myocardial infarction is:
پاسخ دهید
(C)
CK-2
3
What is the role of the enzyme, Trypsin?
پاسخ دهید
(C)
Digestion of proteins and polypeptides in the small intestine
4
In feedback inhibition, the end product of a metabolic pathway typically acts as a(n):
پاسخ دهید
(B)
Inhibitor of the first enzyme.
5
What is the role of ATP in some enzyme reactions?
پاسخ دهید
(B)
It provides energy.
6
What is the major clinical application of the enzyme Collagenase?
پاسخ دهید
(B)
Removing dead tissue from wounds
7
Which of the following is NOT a characteristic of enzymes?
پاسخ دهید
(B)
They are consumed in the reaction.
8
What is the name of the model that explains that an enzyme has a rigid shape, like a lock?
پاسخ دهید
(B)
Lock and key model
9
The enzyme useful in the treatment of leukemia is:
پاسخ دهید
(B)
Asparaginase
10
What are the main features of competitive inhibitors?
پاسخ دهید
A
B
C
11
A competitive inhibitor:
پاسخ دهید
(A)
Binds to the active site.
12
Which of the following is NOT an example of an enzyme used in clinical diagnostics?
پاسخ دهید
(D)
Trypsin
13
Which type of enzyme inhibitor binds to a site distinct from the active site and, upon binding, alters the enzyme's conformation and catalytic activity?
پاسخ دهید
(B)
Noncompetitive
14
Which of the following is an example of a mechanism-based inhibitor?
پاسخ دهید
(B)
Penicillin
15
Transaminases enzyme belong to the class:
پاسخ دهید
(B)
Transferases
16
What is the primary function of the enzyme, Amylase?
پاسخ دهید
(C)
Digestion of carbohydrates (starch).
17
What is the role of a catalyst?
پاسخ دهید
(C)
To speed up a reaction without being consumed.
18
Which type of inhibition does not alter the Km value?
پاسخ دهید
(B)
Noncompetitive inhibition
19
Which of the following enzyme levels increases in obstructive jaundice?
پاسخ دهید
C
D
20
Which of the following statements is correct regarding enzyme inhibitors?
پاسخ دهید
A
C
D
21
How does a competitive inhibitor affect the reaction rate?
پاسخ دهید
(D)
It can increase or decrease the rate, depending on the substrate concentration.
22
What does the Lineweaver-Burk plot is used for?
پاسخ دهید
(C)
To determine Vmax and Km values.
23
What is the general role of an isomerase?
پاسخ دهید
(C)
To catalyze the rearrangement of atoms within a molecule.
24
Enzymes may be used as the following, except:
پاسخ دهید
(D)
Nutrients
25
What are the common clinical applications of measuring LDH isoenzymes?
پاسخ دهید
(D)
All of the above
26
How do allosteric enzymes regulate biochemical pathways?
پاسخ دهید
(C)
By being regulated by modulators
27
Which type of inhibitor affects both the Km and Vmax of an enzyme?
پاسخ دهید
(C)
Uncompetitive
28
Which inhibitor type results in a decrease in both the Km and Vmax?
پاسخ دهید
(C)
Uncompetitive inhibitor
29
Which of the following is used in the treatment of some types of leukemia?
پاسخ دهید
(B)
Asparaginase
30
Which enzyme is useful for dissolving fibrin clots?
پاسخ دهید
(C)
Streptokinase
31
Which type of enzyme is involved in the transfer of phosphate groups?
پاسخ دهید
(B)
Transferase
32
The 'lock and key' model explains that the enzyme and substrate:
پاسخ دهید
(A)
Fit perfectly together.
33
What would be the effect of a non-competitive inhibitor on a Lineweaver-Burk plot?
پاسخ دهید
(A)
The y-intercept changes and the x-intercept remains the same.
34
Which of the following enzyme classifications catalyze the formation of bonds with the input of ATP?
پاسخ دهید
(B)
Ligases
35
The Michaelis constant (Km) is:
پاسخ دهید
(C)
The substrate concentration at 1/2 Vmax
36
What is a common clinical application of measuring lipase?
پاسخ دهید
(C)
Diagnosis of pancreatitis
37
What is the role of alkaline phosphatase in clinical diagnosis?
پاسخ دهید
(A)
Diagnosis of liver disease and bone disorders
38
What is the effect of an irreversible inhibitor on an enzyme?
پاسخ دهید
(B)
It permanently inactivates the enzyme.
39
In which type of enzyme inhibition does the inhibitor bind to a site distinct from the active site, but changes the shape of the active site?
پاسخ دهید
(B)
Non-competitive inhibition
40
Enzyme activity in biological systems may be affected by the following:
پاسخ دهید
A
B
C
D
41
Which of the following enzymes is classified as a hydrolase?
پاسخ دهید
(C)
Amylase
42
Liver diagnostic enzyme is:
پاسخ دهید
(C)
Alanine transaminase
43
What does Vmax represent?
پاسخ دهید
(B)
The maximum reaction rate.
44
Which enzyme is elevated in urine in the patient of acute pancreatitis?
پاسخ دهید
(A)
Amylase
45
What is the normal serum value for adult of Alkaline phosphatase (ALP)?
پاسخ دهید
(C)
13 to 100 U/L
46
Which of the following can affect enzyme activity?
پاسخ دهید
A
B
C
D
47
Which enzyme, elevated in serum, is used for diagnosis of acute myocardial infarction?
پاسخ دهید
(B)
Creatine Kinase (CK-MB)
48
Which of the following is a characteristic of uncompetitive inhibitors?
پاسخ دهید
(B)
They bind only to the enzyme-substrate complex.
49
What is the primary function of the enzyme amylase?
