Biomolecules
LECTURE – 9
ENZYMES Telegram Link:-https://t.me/RITULIVE
Daily Practice Paper
(DPP)
Telegram Link:-https://t.me/RITULIVE
1. The catalytic cycle of an enzyme action can be described in the following steps. Arrange them in
sequence accordingly.
1) The binding of the substrate induces the enzyme to alter its shape, fitting more tightly
around the substrate.
2) The substrate binds to the active site of the enzyme, fitting into the active site.
3) The enzyme releases the products of the reaction and the free enzyme is ready to bind to
another molecule of the substrate and run through the catalytic cycle once again.
4) The active site of the enzyme, now in close proximity of the substrate breaks the chemical
bonds of the substrate and the new enzyme product complex is formed.
(1) 1 → 2 → 3 → 4 (2) 2 → 1 → 4 → 3
(3) 1 → 2 → 4 → 3 (4) 2 → 1 → 3 → 4
Telegram Link:-https://t.me/RITULIVE
2. Which one is correct?
1) E + S → ES → EP → EP
2) E + S → ES → EP → E + P
3) E + S → ES → EP → E – P
4) E + S → ES → EP → E – P
Telegram Link:-https://t.me/RITULIVE
3. Enzymes which catalyse oxidoreduction between two substrate
belongs to the class
1) Oxidoreductase
2) Transferase
3) Hydrolase
4) Ligase
Telegram Link:-https://t.me/RITULIVE
4. Enzymes which catalyse hydrolysis of ester, ether, peptide, glycosidic
bond belongs to the class
1) Oxidoreductase
2) Transferase
3) Hydrolase
4) Ligase
Telegram Link:-https://t.me/RITULIVE
5. Enzymes that catalyse removal of groups from substrates by mechanisms
other than hydrolysis leaving double bonds is known as
1) Oxidoreductase
2) Transferase
3) Hydrolase
4) Lyase
Telegram Link:-https://t.me/RITULIVE
6. Enzymes which catalyse the inter-conversion of optical, geometric or
positional isomers belongs to the class of class
1) Isomerase
2) Transferase
3) Hydrolase
4) Ligase
Telegram Link:-https://t.me/RITULIVE
7. Enzymes catalysing the linking together of two compounds, for
example enzymes which catalyse the joining of C-O, C-S, C-N, P-O,
etc., bonds, belongs to the class of
1) Isomerases
2) Transferases
3) Hydrolases
4) Ligases
Telegram Link:-https://t.me/RITULIVE
8. How many types of cofactor can be identified?
1) 1
2) 2
3) 3
4) 4
Telegram Link:-https://t.me/RITULIVE
9. Which one of the following is not a cofactor?
1) Coenzyme
2) Metal ions
3) Prosthetic group
4) Apoenzyme
Telegram Link:-https://t.me/RITULIVE
10. Which of the following describes the given graph correctly?
1) Exothermic reaction with energy A in presence of enzyme and B in absence of enzyme
2) Endothermic reaction with energy A in absence of enzyme and B in presence of enzyme
3) Exothermic reaction with energy A in absence of enzyme and B in presence of enzyme
4) Endothermic reaction with energy A in presence of enzyme and B in absence of enzyme
Telegram Link:-https://t.me/RITULIVE
(1) 2
(2) 2
(3) 1
(4) 3
(5) 4
(6) 1
(7) 4
(8) 3
(9) 4
(10) 1
Telegram Link:-https://t.me/RITULIVE
You Tube
Practice Question
Telegram Link:-https://t.me/RITULIVE
1 . Almost all enzymes are
1) Proteins
2) Nucleic acid
3) Carbohydrates
4) Vitamins
Telegram Link:-https://t.me/RITULIVE
2. There are some nucleic acids that behaves like enzymes and are called
1) DNase
2) RNase
3) Endonuclease
4) Ribozymes
Telegram Link:-https://t.me/RITULIVE
3. _________ of an enzyme is a crevices or pocket into which substrate
fits.
1) Inactive site
2) Active site
3) Allosteric site
4) Any of these
Telegram Link:-https://t.me/RITULIVE
4. Select the incorrect statement from the following:
1) Active enzyme has tertiary structure having many active sites
(substrate binding sites).
2) Enzymes are biocatalyst.
3) Enzymes can occur in viruses.
4) Enzymes are mainly proteinaceous in nature.
Telegram Link:-https://t.me/RITULIVE
5. Enzymes which catalyse transfer of group other than hydrogen belongs to the
class
1) Oxidoreductase
2) Transferase
3) Hydrolase
4) Ligase
Telegram Link:-https://t.me/RITULIVE
6. There could be many more altered structural states (like transition
state) between the stable substrate and the product in enzymatic
reaction. These structural states are
1) Stable
2) Unstable
3) Metastable
4) Of lower energy than both substrate and product
Telegram Link:-https://t.me/RITULIVE
7. Each enzyme shows its highest activity at particular temperature and pH
called the ______ temperature and ______ pH.
1) optimum, optimum
2) minimum, minimum
3) maximum, maximum
4) minimum, maximum
Telegram Link:-https://t.me/RITULIVE
8. The activity of an enzyme is also sensitive to the presence of specific
chemicals that bind to the enzyme. When the binding of the chemical
shuts off enzyme activity, the process is called _________ and the
chemical is called an _________ .
1) activation, activator
2) inhibition, inhibitor
3) Inhibition, promoter
4) activation, inhibitor
Telegram Link:-https://t.me/RITULIVE
9. Inhibition of succinate dehydrogenase by malonate is an example of
1) Non-competitive inhibition
2) Negative feed back
3) Allosteric inhibition
4) Competitive inhibition
Telegram Link:-https://t.me/RITULIVE
10. Enzymes are divided into
1) 6 classes, each with 4–13 subclasses and named accordingly by a
four-digit number.
2) 7 classes, each with 3–13 subclasses and named accordingly by a
four-digit number.
3) 7 classes, each with 4–13 subclasses and named accordingly by a
three-digit number.
4) 6 classes, each with 4–20 subclasses and named accordingly by a
four-digit number.
Telegram Link:-https://t.me/RITULIVE
(1) 1
(2) 4
(3) 2
(4) 1
(5) 2
(6) 2
(7) 1
(8) 2
(9) 4
(10) 1
Telegram Link:-https://t.me/RITULIVE
