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
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
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.
Description : The minimum energy required to allow a chemical reaction to proceed is termed as the 'threshold energy '. Chemical reactions with low activation energy are: (A) Always irreversible (B) Insensitive to temperature changes (C) Mostly irreversible (D) Highly temperature sensitive
Last Answer : (B) Insensitive to temperature changes
Description : The difference between Threshold energy and average energy of the molecules is called activation energy. Ina chemical reaction lowers the rate of reaction the greater will be. The activation energy
Last Answer : How do you define the molecularity of a reaction ?
Description : An enzyme promotes a chemical reaction by (A) Lowering the energy of activation (B) Causing the release of heat which acts as a primer (C) Increasing molecular motion (D) Changing the free energy difference between substrate and product
Last Answer : Answer : A
Description : Chemical reaction vs enzymatic reaction -Biology
Last Answer : answer:
Description : The figure given Progress of Reaction Product Substrate B A C D below shows the conversion of a substrate into product by an enzyme. In which one of the four options (A-D ... enzyme enzyme (d) Activation Transition Activation Potential energy state energy energy with without enzyme enzyme
Last Answer : (b) Transition Potential Activation Activation state energy energy energy without with enzyme enzyme
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
Description : A metabolic pathways is a (A) Route taken by chemicals (B) Sequence of enzyme facilitated chemical reactions (C) Route taken by an enzyme from one reaction to another (D) Sequence of origin of organic molecules
Description : Feedback term refers to (A) Effect of substrate on rate of enzymatic reaction (B) Effect of end product on rate reaction (C) Effect of enzyme concentration on rate of reaction (D) Effect of external compound on rate of reaction
Description : When the velocity of an enzymatic reaction equals Vmax, substrate concentration is (A) Half of Km (B) Equal to Km (C) Twice the Km (D) Far above the Km
Last Answer : Answer : D
Description : Fight-or-flight reactions cause activation of (a) the parathyroid glands, leading to increased metabolic rate (b) the kidney, leading to suppression of renin- angiotensin-aldosterone pathway (c) ... epinephrine and norepinephrine (d) the pancreas leading to a reduction in the blood sugar levels.
Last Answer : (c) the adrenal medulla, leading to increased secretion of epinephrine and norepinephrine
Description : Metabolism is carried out by a large class of proteins that decrease the activation energy required for chemical reactions inside a cell. Therefore they only facilitate reactions that would naturally occur at a much slower rate. What is the name of these proteins that speed up biochemical reactions?
Last Answer : Enzymes
Description : Pick out the wrong statement. (A) A particular chemical reaction is more temperature sensitive at low temperatures (B) A very high value of equilibrium constant, K (K >> 1) indicates that the ... ) Non-ideal flow takes place in reactors due to recycling, channeling or by creation of stagnant regions
Last Answer : (C) The intercept of the Arrhenius plot is called the 'activation energy
Description : If the Keq for an enzymatic reaction is greater than 1, the reaction A- will be endergonic B- can not occur without the input of energy C- both (a) and (b) D- none of these
Last Answer : none of these
Description : The role of a catalyst in a chemical reaction is to change the (A) Equilibrium constant (B) Activation energy (C) Final products (D) Heat of reaction
Last Answer : (B) Activation energy
Description : Pick out the wrong statement. (A) In a multistep reaction, the slowest step is the rate determining step (B) In general, the rate of a reaction becomes triple for every 10°C rise in temperature (C ... energy (D) Molecularity of a reaction cannot be zero but the order of a reaction can be zero
Last Answer : (B) In general, the rate of a reaction becomes triple for every 10°C rise in temperature
Description : Pick out the correct statement. (A) Reactions with high activation energies are very temperature sensitive (B) Chemical equilibrium is a static state (C) A photochemical reaction is catalysed by ... occurs when the energy of the reacting molecule is less than the activation energy of the reaction
Last Answer : (A) Reactions with high activation energies are very temperature sensitive (B) Chemical equilibrium is a static state
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
Description : A catalyst (A) Initiates a reaction (B) Lowers the activation energy of reacting molecules (C) Is capable of reacting with any one of the reactants (D) Cannot be recovered chemically unchanged at the end of a chemical reaction
Last Answer : (C) Is capable of reacting with any one of the reactants
Description : Pick out the wrong statement: (A) Chemical reactions with high activation energy are very temperature sensitive (B) A flat velocity profile exists in a plug flow reactor (C) The residence ... D) Half life of a reaction increases with increased initial concentration for reaction orders more than one
Last Answer : (C) The residence time for all the elements of fluid in case of a P.F.R. need not be same
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
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
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
Description : Higher free energy of activation of a chemical reaction (at a given temperature) implies (A) Slower rate of reaction (B) Higher rate of reaction (C) Higher equilibrium conversion (D) Both (B) and (C)
Last Answer : (A) Slower rate of reaction
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
Description : The energy of activation of a chemical reaction: (A) Is same as heat of reaction at constant pressure (B) Is the minimum energy which the molecules must have before the reaction can take place (C) Varies as fifth power of the temperature (D) Both (B) and (C)
Last Answer : (B) Is the minimum energy which the molecules must have before the reaction can take place
Description : The catalyst in a first order chemical reaction changes the (A) Equilibrium constant (B) Activation energy (C) Heat of formation of the product (D) Heat of reaction
Description : A catalyst in a chemical reaction (A) Decreases the activation energy (B) Alters the reaction mechanism (C) Increases the frequency of collisions of reacting species (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
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
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
Description : An increase in which of the following results in a decrease in the rate of the chemical reaction? (a) temperature (b) concentration (c) collision frequency (d) energy of activation
Last Answer : energy of activation
Description : Which one of the following statements regarding a catalyst is not correct? A An enzyme is a catalyst that only binds certain substrates. B An enzyme is a protein that is a highly ... increasing the activation energy. D Catalysts do not alter the equilibrium constant for a chemical reaction.
Last Answer : C Catalysts increase the rate of a reaction by altering the mechanism, thereby increasing the activation energy.
Description : How many high-energy phosphate bond equivalents are required for amino acid activation in protein synthesis? (A) One (B) Two (C) Three (D) Four
Description : An enzyme brings about (A) Decrease in reaction time (B) Increase in reaction time (C) Increase in activation energy (D) Reduction in activation energy
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
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
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
Description : How does facilitated diffusion present similarities with enzymatic chemical reactions ?
Last Answer : One of the main examples of facilitated transport is the entrance of glucose from the blood into cells. Glucose from blood binds to specific permeases (hexose-transporting permeases) present in the ... job is concluded the permease is not consumed and can perform successive other transports.
Description : Chemical digestion is the series of enzymatic reactions to break macromolecules into smaller ones.
Last Answer : Which type of chemical reaction is the breaking of macromolecules into smaller ones that occurs in digestion? What are the enzymes that participate in this process called?
Description : Mechanical digestion is the fragmentation of food aided by specialized physical structures, such as teeth, previous to extracellullar digestion. The mechanical fragmentation of food helps digestive ... there are mandibles and chewing muscles to triturate food previous to the chemical digestion.
Last Answer : Concerning extracellular digestion what is meant by chemical digestion?
Description : In the mammalian body, this element plays many important roles. Try to identify this element with the fewest number of clues. This element is required to insure the integrity and permeability of ... involved in blood coagulation and is the most important element of bone salt. Name this element.
Last Answer : ANSWER: Calcium
Description : Transition state structure of the substrate formed during an enzymatic reaction is (a) transient and unstable (b) permanent and stable (c) transient but stable (d) permanent but unstable.
Last Answer : (a) transient and unstable
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
Description : The catalytic activity of enzymes is due to their capacity to lower the __________ energy. (A) Activation (B) Potential (C) Kinetic (D) None of these
Description : A protein having both structural and enzymatic traits is (A) Myosin (B) Collagen (C) Trypsin (D) Actin
Description : The fatty acid synthase complex catalyses (A) 4 sequential enzymatic steps (B) 6 sequential enzymatic steps (C) 7 sequential enzymatic steps (D) 8 sequential enzymatic steps
Description : The following ions help in enzymatic transfer of phosphate from ATP to pyruvic acid: (A) Sodium (B) Calcium (C) Magnesium (D) Potassium
Description : Calcium is required for the activation of the enzyme: (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase