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