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