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