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Quick Biochemistry - Enzymes (Section 1)

1
Which compound exhibits the lowest density among the following?
Answer
(A)
Chylomicron
2
What enzyme's activity is inhibited by non-steroidal anti-inflammatory drugs like aspirin?
Answer
(B)
Cyclooxygenase
3
What enzyme catalyzes the synthesis of prostaglandins from arachidonate?
Answer
(A)
Cyclooxygenase
4
What best describes a Holoenzyme?
Answer
(D)
All of these
5
Which enzyme deficiency is associated with Gaucher's disease?
Answer
(C)
ẞ-Glucosidase
6
What enzyme deficiency is the cause of Neimann-Pick disease?
Answer
(D)
Sphingomyelinase
7
Which enzyme is deficient in Krabbe's disease?
Answer
(C)
ẞ-Galactosidase
8
Fabry's disease results from a deficiency of which enzyme?
Answer
(A)
Ceramide trihexosidase
9
Farber's disease is caused by a deficiency in which enzyme?
Answer
(B)
Ceramidase
10
Which synthetic nucleotide analogue is used to prevent immunologic rejection in organ transplantation?
Answer
(D)
6-Mercaptopurine
11
Which of the following is an example of an enzyme that functions outside of a cell?
Answer
(C)
Pancreatic lipase
12
What term describes enzymes that are produced in an inactive state within living cells?
Answer
(D)
Proenzymes
13
Which of the following enzymes is classified as a ligase?
Answer
(A)
Succinate thiokinase
14
Which enzyme listed is an example of a lyase?
Answer
(B)
Fumarase
15
Covalent modification of which amino acid often regulates enzyme activity?
Answer
(D)
Serine
16
What type of enzyme catalyzes the addition or removal of water across a carbon-carbon double bond without breaking the bond?
Answer
(A)
Hydratase
17
According to the 'lock and key' model of enzyme action, what is the relationship between the enzyme's active site and the substrate?
Answer
(B)
The active site is complementary in shape to that of substance
18
In the Lineweaver-Burk plot based on the Michaelis-Menten equation, how are the substrate concentrations typically represented on the x-axis?
Answer
(C)
1/S
19
A sigmoidal curve when plotting substrate concentration against reaction velocity is suggestive of what type of enzyme behavior?
Answer
(B)
Co-operative binding
20
Determine the K value of the enzyme giving the kinetic data as below.
Answer
(D)
+0.33
21
What impact does a purely competitive inhibitor have on an enzyme's kinetic properties?
Answer
(A)
Raises the Km without changing the Vmax
22
If a graph illustrates an enzymatic reaction without inhibition (curve X), which curve would represent competitive inhibition of the same reaction?
Answer
(A)
A
23
What type of enzyme typically does not require an inducer?
Answer
(B)
Constitutive enzyme
24
In which type of enzyme is a measurable inducer typically absent?
Answer
(B)
Constitutive enzyme
25
What is the outcome of reversible non-competitive enzyme inhibition?
Answer
(D)
The concentration of the active enzyme is lowered
26
Regarding reversible non-competitive enzyme activity inhibition:
Answer
(B)
The inhibitor reduces the maximum reaction rate achievable with a specific enzyme amount
27
What is a characteristic of competitive enzyme activity inhibition?
Answer
(A)
The inhibitor's structure generally mirrors that of the substrate
28
In enzyme kinetics, what does Vmax represent?
Answer
(A)
The amount of active enzyme
29
What is the meaning of Km in enzyme kinetics?
Answer
(A)
The substrate concentration that results in half-maximal velocity
30
Which of the following statements describes competitive enzyme activity inhibition?
Answer
(B)
Apparent Km is increased
31
In non-competitive enzyme inhibition, what impact does the inhibitor have on the enzyme's Km value?
Answer
(C)
Leaves Km unchanged
32
What type of enzyme uses oxygen during oxidoreduction reactions as an acceptor of hydrogen atoms?
Answer
(A)
Cytochrome oxidase
33
Which enzyme utilizes a substance other than oxygen as the hydrogen acceptor?
Answer
(B)
Succinate dehydrogenase
34
Which enzyme utilizes hydrogen acceptors as its substrate?
Answer
(C)
Catalase
35
Which of the following enzymes is primarily responsible for linking two substrates?
Answer
(A)
Glutamine synthetase
36
What is the typical optimal pH range for the activity of most enzymes?
Answer
(B)
Between 5 and 9
37
What is the nature of coenzymes?
Answer
(A)
Heat-stable, dialyzable, non-protein organic molecules
38
Which of the following is an example of a coenzyme that transfers hydrogen atoms?
Answer
(B)
NAD+
39
Which of the following is an example of a coenzyme involved in the transfer of chemical groups?
Answer
(D)
COA
40
Cocarboxylase is also known as:
Answer
(A)
Thiamine pyrophosphate
41
Which coenzyme features a non-aromatic heterocycle?
Answer
(D)
Biotin
42
Which coenzyme contains an aromatic heterocycle?
Answer
(A)
TPP
43
What best describes isoenzymes?
Answer
(A)
Forms of an enzyme that are chemically, immunologically, and electrophoretically distinct
44
How can isoenzymes be characterized?
Answer
(B)
Enzymes activated by hydrolysis
45
Regarding the isoenzymes of LDH, which statement is correct?
Answer
(C)
They exist in 5 forms based on M and H monomer ratios
46
What is a typical range for CPK values in blood serum?
Answer
(A)
4-60 IU/L
47
Which factors influence enzyme activity?
Answer
(D)
All of these
48
What is the typical range for GOT activity in blood serum?
Answer
(B)
4.0-17.0 IU/L
49
What is the typical range for GPT activity in blood serum?
Answer
(C)
3.0-15.0 IU/L
50
What is a typical range for serum acid phosphatase activity?
Answer
(B)
1.0-5.0 KA units/100 ml