Questions
Which of the following biomolecules constitute enzymes?
- Carbohydrates
- Fats
- Proteins
- Nucleic acids
- Inorganic compounds
What is an apoenzyme?
- Enzyme + prosthetic group
- Enzymes having the same function, but a different molecular configuration are called holoenzymes
- Inactive form of enzymes
- The protein part of an enzyme
- Non-protein part of an enzyme
What is the Michaelis-Menten's equation used for?
- To study the enzyme kinetics
- To determine the quantity of product formed per gram of the enzyme
- To study the nature of an enzyme
- To determine the optimum temperature required to carry out a reaction
- To determine the structure of the enzyme
What does Michaelis Menten constant Km signifies?
- Concentration of substrate
- Affinity of an enzyme for its substrate
- Both (1) and (2)
- It is the t1/2 of the reaction.
- The rate at which ES complex dissociates to form the product.
According to which theory does the enzyme molecule undergo changes at active site on contact with a substrate?
- Fischer's lock and key model
- Koshland's induced fit model
- Michaelis Menten hypothesis
- Lineweaver- Burk equation
- Autocatalysis
Which are the main assumptions of Michaelis Menten hypothesis?
- A single substrate and a single product are involved.
- An intermediate enzyme-substrate complex is formed.
- The rate of decomposition of the substrate is proportional to the concentration of enzyme-substrate complex.
- All 1, 2 and 3
- One enzyme can lead to the formation of many products.
According to which theory does a substrate fit in the enzyme like a key fits in a lock to yield a enzyme-substrate complex?
- Koshland's induced fit model
- Michaelis Menten hypothesis
- Fischer's lock and key model
- Lineweaver-Burk equation
- Autocatalysis
What is meant by feedback inhibition?
- Inhibition of enzyme activity at an active site by an inhibitor which is structurally similar to a substrate
- Inhibition of first step of biosynthesis by the end-product of reaction
- Inhibition by a structurally different inhibitor at a place other than active site
- Denaturation of enzyme
- Mixed competitive and non-competitive inhibition
If melonic acid inhibits succinic acid dehydrogenase which catalyses the conversion of succinic acid to fumaric acid, which type of process takes place?
- Feedback inhibition
- Competitive inhibition
- Non-competitive inhibition
- Zymogen activation
- Denaturation of enzyme
Which of the following class of enzymes would convert glucose-6-phosphate to fructose-6-phosphate?
- Synthases
- Isomerases
- Oxidoreductases
- Hydrolases
- Transferases
Which type of inhibition is the sensitivity of urease to various ions of heavy metals?
- Feedback inhibition
- Competitive inhibition
- Non-competitive inhibition
- Zymogen activation
- Denaturation
In which of the following enzymes, is nickel used as a co-factor?
- Catalase
- Arginase
- Urease
- Nitrogenase
- Hydrogenase
Which of the following enzymes fall under the class of hydrolases?
- Dehydrogenase, Oxidase
- Transaminase, Transphosphatase
- Protease, Carbohydrases
- Phosphohexose isomerase
- Pyruvate carboxylase
What is a complete enzyme known as?
- Apoenzyme
- Holoenzyme
- Pro-enzyme
- Isoenzyme
- Exoenzyme
Who among the following coined the word enzyme?
- Edward Buchner
- J. B. Sumner
- W. Kuhne
- Emil Fischer
- D.E. Koshland