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