The catalytic activity of enzymes is due to their capacity to lower the __________ energy. (A) Activation (B) Potential (C) Kinetic (D) None of these

The catalytic activity of enzymes is due to their capacity to lower the
__________ energy.
(A) Activation
(B) Potential
(C) Kinetic
(D) None of these
by

1 Answer

Answer :

(A) Activation
by

Related questions

The catalytic power of enzymes is due to (a) the presence of amino acids in their structures (b) their high molecular weight (c) their ability to lower the activation energy of the reaction (d) their limited solubility in water and other solvents

Description : The catalytic power of enzymes is due to (a) the presence of amino acids in their structures (b) their high molecular weight (c) their ability to lower the activation energy of the reaction (d) their limited solubility in water and other solvents

Last Answer : Ans:(c)

Pick out the wrong statement. (A) Catalytic activity of enzyme catalysed reactions which is affected by temperature, pH value & chemical agents, is maximum at a temperature of about 45°C(B) Most of the enzyme catalysed reactions involve at least two substrates (C) Enzymes help in increasing the activation energy of the reaction (D) Equilibrium concentrations in enzyme catalysed reactions can be calculated by using the thermodynamic properties of substrates & prod

Description : Pick out the wrong statement. (A) Catalytic activity of enzyme catalysed reactions which is affected by temperature, pH value & chemical agents, is maximum at a temperature of about 45°C ... in enzyme catalysed reactions can be calculated by using the thermodynamic properties of substrates & prod

Last Answer : (C) Enzymes help in increasing the activation energy of the reaction

Enzymes (a protein) are catalysts found in organisms. Its efficiency of catalysing a reaction is due to its capacity to lower the activation energy of the reaction. The enzyme ptyalin used for food digestion is present in (A) Blood (B) Saliva (C) Intestine (D) Gland

Description : Enzymes (a protein) are catalysts found in organisms. Its efficiency of catalysing a reaction is due to its capacity to lower the activation energy of the reaction. The enzyme ptyalin used for food digestion is present in (A) Blood (B) Saliva (C) Intestine (D) Gland

Last Answer : (B) Saliva

If the pore diffusion controls in a catalytic reaction, the apparent activation energy Ea is equal to (A) The intrinsic activation energy E (B) (E + ED) where ED is activation due to diffusion (C) (E + ED)/2 (D) ED/2

Description : If the pore diffusion controls in a catalytic reaction, the apparent activation energy Ea is equal to (A) The intrinsic activation energy E (B) (E + ED) where ED is activation due to diffusion (C) (E + ED)/2 (D) ED/2

Last Answer : (D) ED/2

The increase in the rate of reaction with temperature is due to (A) Increase in the number of effective collisions (B) Decrease in activation energy (C) Increase in the average kinetic energy of the reacting molecules (D) None of these

Description : The increase in the rate of reaction with temperature is due to (A) Increase in the number of effective collisions (B) Decrease in activation energy (C) Increase in the average kinetic energy of the reacting molecules (D) None of these

Last Answer : (B) Decrease in activation energy

Enzymes combine with a ___________at the___________ site to lower the activation energy. a. Substrate; Active b. Product; Noncompetitive c. Product; Active d. Coenzyme; Active

Description : Enzymes combine with a ___________at the___________ site to lower the activation energy. a. Substrate; Active b. Product; Noncompetitive c. Product; Active d. Coenzyme; Active

Last Answer : a. Substrate; Active

For a heterogeneous catalytic reaction (A) Free energy of activation is lowered in the presence of catalyst, which remains unchanged at the end of reaction (B) A relatively small amount of catalyst can cause the conversion of large amount of reactants which does not mean that catalyst concentration is important (C) The catalyst does not form an intermediate complex with the reactant (D) The surface of the catalyst does not play an important role during reaction

Description : For a heterogeneous catalytic reaction (A) Free energy of activation is lowered in the presence of catalyst, which remains unchanged at the end of reaction (B) A relatively small amount of catalyst ... with the reactant (D) The surface of the catalyst does not play an important role during reaction

Last Answer : (A) Free energy of activation is lowered in the presence of catalyst, which remains unchanged at the end of reaction

Catalytic action in a catalytic chemical reaction follows from the ability of catalyst to change the (A) Activation energy (B) Equilibrium constant (C) Heat of reaction (D) None of these

Description : Catalytic action in a catalytic chemical reaction follows from the ability of catalyst to change the (A) Activation energy (B) Equilibrium constant (C) Heat of reaction (D) None of these

Last Answer : (A) Activation energy

Pick out the wrong statement. (A) Use of different catalysts in a reversible catalytic chemical reaction does not change the equilibrium composition (B) Alumina is added as a promoter to iron catalyst in ammonia synthesis reaction (C) Activation energy for a reaction is obtained from the intercept of the Arrhenius plot (D) Presence of inerts affects the equilibrium conversion of reactants in a chemical reaction

Description : Pick out the wrong statement. (A) Use of different catalysts in a reversible catalytic chemical reaction does not change the equilibrium composition (B) Alumina is added as a promoter to ... Arrhenius plot (D) Presence of inerts affects the equilibrium conversion of reactants in a chemical reaction

Last Answer : (C) Activation energy for a reaction is obtained from the intercept of the Arrhenius plot

Pick out the correct statement. (A) In catalytic reactions, the catalyst reacts with the reactants (B) A catalyst initiates a chemical reaction (C) A catalyst lowers the activation energy of the reacting molecules (D) A catalyst cannot be recovered chemically unchanged at the end of the chemical reaction

Description : Pick out the correct statement. (A) In catalytic reactions, the catalyst reacts with the reactants (B) A catalyst initiates a chemical reaction (C) A catalyst lowers the activation energy of ... molecules (D) A catalyst cannot be recovered chemically unchanged at the end of the chemical reaction

Last Answer : (C) A catalyst lowers the activation energy of the reacting molecules

The rate expression for a heterogeneous catalytic reaction is given by, - rA = K.KA PA(1 + KA.PA + KR.PR), where K is surface reaction rate constant and KA and KR are absorption equilibrium constants of A and R respectively. If KR PR >> (1 + KA PA), the apparent activation energy EA is equal to (given E is the activation energy for the reaction and ΔHR and ΔHA are the activation energies of adsorption of R and A) (A) E (B) E + ΔHA (C) E + ΔHA - ΔHR ) (D) ΔHA + ΔHR

Description : The rate expression for a heterogeneous catalytic reaction is given by, - rA = K.KA PA(1 + KA.PA + KR.PR), where K is surface reaction rate constant and KA and KR are absorption equilibrium constants of A and R respectively. If KR PR ... R and A) (A) E (B) E + ΔHA (C) E + ΔHA - ΔHR ) (D) ΔHA + ΔHR

Last Answer : (C) E + ΔHA - ΔHR )

Isoenzymes can be characterized by (A) Proteins lacking enzymatic activity that are necessary for the activation of enzymes (B) Proteolytic enzymes activated by hydrolysis (C) Enzymes with identical primary structure (D) Similar enzymes that catalyse different reaction

Description : Isoenzymes can be characterized by (A) Proteins lacking enzymatic activity that are necessary for the activation of enzymes (B) Proteolytic enzymes activated by hydrolysis (C) Enzymes with identical primary structure (D) Similar enzymes that catalyse different reaction

Last Answer : Answer : B

What happens when a catalyst is added to a system at equilibrium? A The reaction follows an alternative pathway of lower activation energy. B The heat of reaction decreases. C The potential energy of the reactants decreases. D The potential energy of the products decreases. E The rate of chemical reaction decreases.

Description : What happens when a catalyst is added to a system at equilibrium? A The reaction follows an alternative pathway of lower activation energy. B The heat of reaction decreases. C The potential ... decreases. D The potential energy of the products decreases. E The rate of chemical reaction decreases.

Last Answer : A The reaction follows an alternative pathway of lower activation energy.

The excess energy of reactants in a chemical reaction required to dissociate into products is termed as the __________ energy. (A) Activation (B) Potential (C) Binding (D) Threshold

Description : The excess energy of reactants in a chemical reaction required to dissociate into products is termed as the __________ energy. (A) Activation (B) Potential (C) Binding (D) Threshold

Last Answer : (A) Activation

_________ is the energy stored within a body or substance by virtue of the activity and configuration of its molecules.  a. Internal Energy  b. External Energy  c. Kinetic Energy  d. Potential Energy

Description : _________ is the energy stored within a body or substance by virtue of the activity and configuration of its molecules.  a. Internal Energy  b. External Energy  c. Kinetic Energy  d. Potential Energy

Last Answer : Internal Energy

A long thread suspended from a fixed point has a small mass swinging to and fro at its lower end. Then, 1. the potential energy of the mass is minimum in the middle of the swing 2. the kinetic energy is maximum in the middle of the swing 3. the potential energy is always equal to the kinetic energy 4. the sum of the potential energy and the kinetic energy is maximum in the middle of the swing Which of the above statements is/are correct? (a) 1 only (b) 1 and 2 (c) 2 and 4 (d) 1, 2, 3 and 4

Description : A long thread suspended from a fixed point has a small mass swinging to and fro at its lower end. Then, 1. the potential energy of the mass is minimum in the middle of the swing 2. the kinetic energy is maximum in the middle of ... /are correct? (a) 1 only (b) 1 and 2 (c) 2 and 4 (d) 1, 2, 3 and 4

Last Answer : Ans:(b)

In a nuclear explosion, the energy is released primarily in the form of __________ energy. (A) Potential (B) Thermal (C) Kinetic (D) Electrical

Description : In a nuclear explosion, the energy is released primarily in the form of __________ energy. (A) Potential (B) Thermal (C) Kinetic (D) Electrical

Last Answer : (C) Kinetic

A catalyst loses its activity due to (A) Loss in surface area of the active component (B) Agglomeration of metal particles caused by thermal sintering of the solid surface (C) Covering of the catalytic active sites by a foreign substance (D) All (A), (B) and (C)

Description : A catalyst loses its activity due to (A) Loss in surface area of the active component (B) Agglomeration of metal particles caused by thermal sintering of the solid surface (C) Covering of the catalytic active sites by a foreign substance (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

What lowers activation energy in enzymes?

Description : What lowers activation energy in enzymes?

Last Answer : This is the most important concern of Biochemistry, theenzyme-catalyzed reactions. The main factor that lowers theactivation energy, is the catalysis. Catalysts act by reducing theactivation barrier for ... fold rate acceleration occurs only with asmall fraction of the energy of most covalent bonds.

Enzymes increases the rate of reactions by (A) Increasing the free energy of activation (B) Decreasing the energy of activation (C) Changing the equilibrium constant of the reaction (D) Increasing the free energy change of the reaction

Description : Enzymes increases the rate of reactions by (A) Increasing the free energy of activation (B) Decreasing the energy of activation (C) Changing the equilibrium constant of the reaction (D) Increasing the free energy change of the reaction

Last Answer : Answer : B

Enzymes increase the rates of reactions by (A) Increasing the free energy of activation (B) Decreasing the energy of activation (C) Changing the equilibrium constant of the reaction (D) Increasing the free energy change of the reaction

Description : Enzymes increase the rates of reactions by (A) Increasing the free energy of activation (B) Decreasing the energy of activation (C) Changing the equilibrium constant of the reaction (D) Increasing the free energy change of the reaction

Last Answer : Answer : B

Enzymes accelerate the rate of reactions by (A) Increasing the equilibrium constant of reactions (B) Increasing the energy of activation (C) Decreasing the energy of activation (D) Decreasing the free energy change of the reaction

Description : Enzymes accelerate the rate of reactions by (A) Increasing the equilibrium constant of reactions (B) Increasing the energy of activation (C) Decreasing the energy of activation (D) Decreasing the free energy change of the reaction

Last Answer : Answer : C

Molecular diffusion is caused by the (A) Transfer of molecules from low concentration to high concentration region (B) Thermal energy of the molecules (C) Activation energy of the molecules (D) Potential energy of the molecules

Description : Molecular diffusion is caused by the (A) Transfer of molecules from low concentration to high concentration region (B) Thermal energy of the molecules (C) Activation energy of the molecules (D) Potential energy of the molecules

Last Answer : (B) Thermal energy of the molecules

Pick out the wrong statement. (A) Exit age description function (E) and internal age distribution function (I) are related as, E = -(dI/dθ) (B) Chemisorption studies are useful in the determination of catalyst surface area and pore size distribution (C) A higher temperature favours the reaction of higher activation energy (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

Description : Pick out the wrong statement. (A) Exit age description function (E) and internal age distribution function (I) are related as, E = -(dI/dθ) (B) Chemisorption studies are useful in the ... energy (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

Last Answer : (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

When a liquid is at its boiling point, no temperature change takes place due to heating. The energy supplied due to heating (a) Is used up to increase the potential energy of the liquid molecules (b) Is used up to increase the kinetic energy of the molecules (c) Is used up to increase the kinetic energy and potential energy of the molecules (d) Is wasted

Description : When a liquid is at its boiling point, no temperature change takes place due to heating. The energy supplied due to heating (a) Is used up to increase the potential energy of the liquid molecules (b ... c) Is used up to increase the kinetic energy and potential energy of the molecules (d) Is wasted

Last Answer : Ans:(a)

The increasing vapor pressure caused by heating a liquid is due to------? A. increase inter-molecular interactions B. increasing potential energy of molecules C. increasing kinetic energy of molecules (Answer) D. decreasing surface tension

Description : The increasing vapor pressure caused by heating a liquid is due to------? A. increase inter-molecular interactions B. increasing potential energy of molecules C. increasing kinetic energy of molecules (Answer) D. decreasing surface tension

Last Answer : C. increasing kinetic energy of molecules (Answer)

Internal state of neuron is called __________, is the function of the inputs the neurons receives A. Weight B. activation or activity level of neuron C. Bias D. None of these

Description : Internal state of neuron is called __________, is the function of the inputs the neurons receives A. Weight B. activation or activity level of neuron C. Bias D. None of these

Last Answer : B. activation or activity level of neuron

Pick out the correct statement. (A) A lower temperature favours the reaction of lower activation energy (B) The dispersion number for a reactor/vessel is uL/D (C) The rate controlling step in a reaction involving many steps is the fastest step (D) Pore volume and porosity of a catalyst is measured by Brunauer￾Emmett-Teller (BET) technique

Description : Pick out the correct statement. (A) A lower temperature favours the reaction of lower activation energy (B) The dispersion number for a reactor/vessel is uL/D (C) The rate controlling step in ... step (D) Pore volume and porosity of a catalyst is measured by Brunauer￾Emmett-Teller (BET) technique

Last Answer : (A) A lower temperature favours the reaction of lower activation energy

If the rate of a chemical reaction becomes slower at a given temperature, then the (A) Initial concentration of the reactants remains constant (B) Free energy of activation is lower(C) Entropy changes(D) Free energy of activation is higher

Description : If the rate of a chemical reaction becomes slower at a given temperature, then the (A) Initial concentration of the reactants remains constant (B) Free energy of activation is lower (C) Entropy changes (D) Free energy of activation is higher

Last Answer : (D) Free energy of activation is higher

The equilibrium constant of a catalytic chemical reaction __________ due to the presence of a catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Unpredictable from the data

Description : The equilibrium constant of a catalytic chemical reaction __________ due to the presence of a catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Unpredictable from the data

Last Answer : (C) Remain unaffected

The energy required to start an enzymatic reaction is called (A) Chemical energy (B) Metabolic energy (C) Activation energy (D) Potential energy

Description : The energy required to start an enzymatic reaction is called (A) Chemical energy (B) Metabolic energy (C) Activation energy (D) Potential energy

Last Answer : Answer : C

The catalytic efficiency of two different enzymes can be compared by the (a) formation of the product (b) pH of optimum value (c) Km value (d) molecular size of the enzyme.

Description : The catalytic efficiency of two different enzymes can be compared by the (a) formation of the product (b) pH of optimum value (c) Km value (d) molecular size of the enzyme.

Last Answer : (c) Km value

Isozymes or iso enzymes are those enzyme which A- have same structural forms B- have different structural forms but identical catalytic properties C- catalyses oxidation reactionsD- none of these

Description : Isozymes or iso enzymes are those enzyme which A- have same structural forms B- have different structural forms but identical catalytic properties C- catalyses oxidation reactions D- none of these

Last Answer : have different structural forms but identical catalytic properties

Isozymes or iso enzymes are those enzyme which A- have same structural forms B- have different structural forms but identical catalytic properties C- catalyses oxidation reactions D- none of these

Description : Isozymes or iso enzymes are those enzyme which A- have same structural forms B- have different structural forms but identical catalytic properties C- catalyses oxidation reactions D- none of these

Last Answer : have different structural forms but identical catalytic properties

Bernoulli's equation describes the (A) Mechanical energy balance in potential flow (B) Kinetic energy balance in laminar flow (C) Mechanical energy balance in turbulent flow (D) Mechanical energy balance in boundary layer

Description : Bernoulli's equation describes the (A) Mechanical energy balance in potential flow (B) Kinetic energy balance in laminar flow (C) Mechanical energy balance in turbulent flow (D) Mechanical energy balance in boundary layer

Last Answer : (A) Mechanical energy balance in potential flow

Acute pancreatitis is characterised by (A) Lack of synthesis of zymogen enzymes (B) Continuous release of zymogen enzymes into the gut (C) Premature activation of zymogen enzymes (D) Inactivation of zymogen enzymes

Description : Acute pancreatitis is characterised by (A) Lack of synthesis of zymogen enzymes (B) Continuous release of zymogen enzymes into the gut (C) Premature activation of zymogen enzymes (D) Inactivation of zymogen enzymes

Last Answer : Answer : C

Activation or inactivation of certain key regulatory enzymes is accomplished by covalent modification of the amino acid: (A) Tyrosine (B) Phenylalanine (C) Lysine (D) Serine

Description : Activation or inactivation of certain key regulatory enzymes is accomplished by covalent modification of the amino acid: (A) Tyrosine (B) Phenylalanine (C) Lysine (D) Serine

Last Answer : Answer : D

Boron in green plants assists in (a) activation of enzymes (b) acting as enzyme co-factor (c) photosynthesis (d) sugar transport.

Description : Boron in green plants assists in (a) activation of enzymes (b) acting as enzyme co-factor (c) photosynthesis (d) sugar transport.

Last Answer : (d) sugar transport.

Trichloroacetic acid, a strong acid, has been used by dentists for chemical cautery of hypertrophic tissue and aphthous ulcers; its mechanism of action is, BOUCHERS P 194 A. Thermodynamic action B. Activation of tissue enzymes C. Osmotic pressure D. Protein precipitation (PPT) E. Neutralization

Description : Trichloroacetic acid, a strong acid, has been used by dentists for chemical cautery of hypertrophic tissue and aphthous ulcers; its mechanism of action is, BOUCHERS P 194 A. Thermodynamic ... Activation of tissue enzymes C. Osmotic pressure D. Protein precipitation (PPT) E. Neutralization

Last Answer : D. Protein precipitation (PPT)

Burning of Gasoline initially requires heat before it burns spontaneously. Which of the following does not give a good explanation of this phenomenon?  a. the initial heat rises the enthalpy of the reactant  b. the initial heat lowers the activation of energy of the reactants  c. the enthalpy of reactants is lower than the enthalpy of products.  d. The enthalpy of the product is lower than the enthalpy of the reactant

Description : Burning of Gasoline initially requires heat before it burns spontaneously. Which of the following does not give a good explanation of this phenomenon?  a. the initial heat rises the enthalpy of the reactant ... of products.  d. The enthalpy of the product is lower than the enthalpy of the reactant

Last Answer : the enthalpy of reactants is lower than the enthalpy of products.

Proteins that cause reactions to proceed more rapidly and lower the energy of activation are called.

Description : Proteins that cause reactions to proceed more rapidly and lower the energy of activation are called.

Last Answer : ANSWER: ENZYMES

Overall rate of reaction in a heterogeneous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually __________ the concentration of catalyst, if it doesnot entail a chain mechanism.(A) Proportional to(B) Independent of(C) Inversely proportional to(D) Proportional to the square o

Description : Overall rate of reaction in a heterogeneous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually __________ the concentration of ... to (B) Independent of (C) Inversely proportional to (D) Proportional to the square o

Last Answer : (A) Proportional to

The catalytic activity of transition metals and their compounds is ascribed mainly to (1) their chemical reactivity (2) their magnetic behaviour (3) their unfilled d-orbitals (4) their ability to adopt variable oxidation states

Description : The catalytic activity of transition metals and their compounds is ascribed mainly to (1) their chemical reactivity (2) their magnetic behaviour (3) their unfilled d-orbitals (4) their ability to adopt variable oxidation states

Last Answer : (4) their ability to adopt variable oxidation states

When the reaction occurs in the diffusion controlled region, the apparent activation energy as measured is only __________ the true value. (A) Twice (B) Half (C) Equal (D) None of these

Description : When the reaction occurs in the diffusion controlled region, the apparent activation energy as measured is only __________ the true value. (A) Twice (B) Half (C) Equal (D) None of these

Last Answer : (B) Half

The excess energy of the reactants required to dissociate into products is known as the __________ energy. (A) Thermal (B) Activation (C) Threshold (D) Binding

Description : The excess energy of the reactants required to dissociate into products is known as the __________ energy. (A) Thermal (B) Activation (C) Threshold (D) Binding

Last Answer : (B) Activation

Arrhenius equation represents graphically the variation between the __________ and temperature. (A) Rate of reaction (B) Frequency factor (C) Rate constant (D) Activation energy

Description : Arrhenius equation represents graphically the variation between the __________ and temperature. (A) Rate of reaction (B) Frequency factor (C) Rate constant (D) Activation energy

Last Answer : (C) Rate constant

Arrhenius equation shows the variation of __________ with temperature. (A) Reaction rate (B) Rate constant (C) Energy of activation (D) Frequency factor

Description : Arrhenius equation shows the variation of __________ with temperature. (A) Reaction rate (B) Rate constant (C) Energy of activation (D) Frequency factor

Last Answer : (B) Rate constant

A chemical reaction occurs when the energy of the reacting molecules is __________ the activation energy of the reaction. (A) Less than (B) Equal to (C) More than (D) Equal to or more than

Description : A chemical reaction occurs when the energy of the reacting molecules is __________ the activation energy of the reaction. (A) Less than (B) Equal to (C) More than (D) Equal to or more than

Last Answer : (D) Equal to or more than

A chemical reaction occurs, when the energy of the reacting molecules is __________ the activation energy of reaction. (A) Less than (B) Equal to (C) More than(D) Equal to or more than

Description : A chemical reaction occurs, when the energy of the reacting molecules is __________ the activation energy of reaction. (A) Less than (B) Equal to (C) More than (D) Equal to or more than

Last Answer : (D) Equal to or more than