Competitive Inhibition

Q.

The Enzyme that is not present in succus entericus is.

1. Lipase

2. Maltase

3. Nucleases

4. Nucleosidase

Q.

How does temperature affect enzyme action?

Q. Name the enzyme that facilitates opening of DNA helix during DNA replication.

1. DNA helicase
2. DNA polymerase
3. RNA polymerase
4. DNA ligase

Q. Which of the following is true for competitive enzyme inhibition?

1. Decrease in $V_{max}$ and $K_m$
2. Unchanged $V_{max}$ and decrease in $K_m$
3. Unchanged $V_{max}$ and increase in $K_m$
4. Increase in $V_{max}$ and $K_m$

Q.

Why does DNA replication go from 5 to 3?

Q.

What are the two different types of nucleases?

Q.

What two factors affect the rate of enzyme action?

Q.

What is primase in DNA replication?

Q.

Ptyalin enzyme is secreted by

1. Salivary gland

2. Mouth

3. Oesophagus

4. Stomach

Q.

What Is Telomerase in DNA Replication?

Q. Which of the following is true for competitive inhibition?

1. $K_m$ decreases but $V_{max}$ increases
2. $K_m$ increases but $V_{max}$ remains the same
3. $K_m$ increases but $V_{max}$ decreases
4. $K_m$ decreases but $V_{max}$ remains the same

Q. Which one of the following statements is incorrect?

1. The competitive inhibitor does not affect the rate of breakdown of the enzyme-substrate complex
2. The presence of the competitive inhibitor decreases the K${}_m$ of the enzyme for the substrate
3. A competitive inhibitor reacts reversibly with the enzyme to form an enzyme-inhibitor complex
4. In competitive inhibition, the inhibitor molecule is not chemically changed by the enzyme

Q.

Provide an example of induced fit.

Q.

What enzyme is used in reverse transcription?

Q. Which of the following is an example of irreversible reaction?

1. Inhibition of methanol by ethanol
2. Inhibition of succinate by malonate
3. Cyanide poisoning
4. All of these

Q.

The name enzyme was coined by

1. Kuhne

2. Buchner

3. Berzelius

4. Pasteur

Q. The given graph shows the effect of substrate concentration on the rate of reaction of the enzyme green-gram-phosphatase. What does the graph indicate?

1. Presence of an enzyme inhibitor in the reaction mixture
2. The rate of the enzyme reaction is directly proportional to the substrate concentration
3. Formation of an enzyme-substrate complex
4. At higher substrate concentration the pH increases

Q.

How are repressible enzymes different from inducible enzymes?

Q.

Which is the largest enzyme in the human body?

Q. Restriction endonucleases hydrolyses polynucleotide at

1. a random internal phosphodiester bond
2. a phosphodiester bond within a specific sequence
3. either terminal
4. only the 5’ end.

Q. Which of the following statements regarding enzyme inhibition is correct?

1. Competivitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein
2. Non -competitive inhibitors often bind to the enzyme irreversibly
3. Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme
4. Non-competitive inhibition of an enzyme can be overcome by adding large amount of substrate

Q.

Describe three characteristics of an enzyme?

Q. The term “molecular scissors” generally refers to

1. DNA polymerases
2. RNA polymerases
3. Restriction endonucleases
4. DNA ligase

Q.

Which coenzyme is used in cellular respiration?

1. NAD+

2. NADP

3. niacin

4. alcohol dehydrogenase

Q. Statement 1: Thermostable Taq polymerase has an effective 3’-5’ proofreading activity.
Statement 2: Thermostable Pfu polymerase does not have any proofreading activities.

1. Both the statements are true
2. Statement 1 is true and statement 2 is false
3. Statement 1 is false and statement 2 is true
4. Both the statements are false

Q.

What are DNA polymerases and their types?

Q. Amino acid acceptor arm of tRNA lies at

1. 3’ end
2. 5’ end
3. $T\Psi C$ loop
4. DHU loop

Q. Which of the following statements regarding enzyme inhibition is correct?

1. Non -competitive inhibitors often bind to the enzyme irreversibly
2. Competivitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein
3. Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme
4. Non-competitive inhibition of an enzyme can be overcome by adding large amount of substrate

Q. A competitive inhibitor of succinate dehydrogenase is:

1. $\alpha$ -ketoglutarte
2. Malate
3. Malonate
4. Oxaloacetate

Q. Name the enzyme that facilitates opening of DNA helix during transcription.

1. DNA polymerase
2. RNA polymerase
3. DNA ligase
4. DNA helicase