The turnover number (kcat) of an enzyme is defined as:
The substrate concentration at which the reaction velocity is half its maximum.
The maximum number of substrate molecules converted to product per enzyme molecule per unit time.
The dissociation constant of the enzyme-substrate complex.
The equilibrium constant for the overall reaction.
Related Questions
Which of the following is NOT a characteristic of a catalyst?
It increases the rate of reaction.
It lowers the activation energy.
It remains unchanged at the end of the reaction.
It alters the equilibrium constant of the reaction.
Catalyst used in Haber’s process is
Nickel powder
Iron and molybdenum powder
Black lead
Iodine
Enzymes are
Microorganism
Proteins
Inorganic compounds
Moulds
A catalyst increases the rate of a reaction by a factor of 1000 at 25°C. If the activation energy of the uncatalyzed reaction is 50 kJ/mol, what is the activation energy of the catalyzed reaction (approximately)? (R = 8.314 J/mol.K)
5 kJ/mol
16.6 kJ/mol
32.2 kJ/mol
48.1 kJ/mol
A catalyst is most effective in finely divided state because
low surface area
greater number of active sites
It dissolves easily in water
It reduces the activation energy to the larger extent
Mutarotation of glucose is an example of :
Acid-base catalysis
Homogeneous catalysis
Both (1) and (2)
None of these
Hydrolysis of urea is an example of
Homogeneous catalysis
Heterogeneous catalysis
Biochemical catalysis
Zeolite catalysis
The efficiency of enzyme catalysis is due to its capacity to
From a strong enzyme-substrate complex
Change the shape of the substrate
Lower the activation energy of the reaction
Form a colloidal solution in water
The enzyme ptyalin used for digestion of food is present in :
Saliva
Blood
Intestine
Adrenal glands
During hydrogenation of oils, catalyst commonly used is :
Pd or
Finely divided Ni
Fe
