Đề 14 – Bài tập, đề thi trắc nghiệm online Hóa sinh enzyme

A A. By binding an activator molecule to the enzyme. B B. By removing a portion of the inactive enzyme precursor (zymogen) through peptide bond cleavage. C C. By increasing the temperature of the enzyme. D D. By changing the pH around the enzyme.

A A. The lock-and-key model. B B. The induced-fit model. C C. The fluid mosaic model. D D. The competitive inhibition model.

A A. The substrate concentration at half Vmax. B B. The maximum reaction rate (Vmax). C C. The number of substrate molecules converted to product per enzyme molecule per unit of time when the enzyme is saturated with substrate. D D. The affinity of the enzyme for its substrate.

A A. Water. B B. ATP or another energy source. C C. Oxygen. D D. A reducing agent.

A A. The substrate concentration required to reach half-maximal velocity. B B. The maximum reaction rate when the enzyme is saturated with substrate. C C. The affinity of the enzyme for its substrate. D D. The initial reaction rate at low substrate concentrations.

A A. Joining two molecules together. B B. Rearranging atoms within a molecule. C C. Breaking a bond using water. D D. Transferring electrons.

A A. To provide structural support to the enzyme. B B. To regulate the enzyme's production in the cell. C C. To bind substrates and catalyze chemical reactions. D D. To transport the enzyme across cell membranes.

A A. Glucose. B B. Ribonucleic acid (RNA). C C. Magnesium ions (Mg²⁺). D D. Deoxyribonucleic acid (DNA).

A A. Allosteric regulation. B B. Feedback inhibition. C C. Covalent modification. D D. Competitive inhibition.

A A. To provide energy for cellular processes directly. B B. To slow down biochemical reactions. C C. To catalyze each step of the metabolic pathway, ensuring efficient and regulated flow of metabolites. D D. To store genetic information for the cell.

A A. To make the enzyme reaction proceed slower. B B. To ensure that the enzyme is fully denatured. C C. To ensure accurate and reproducible measurements of enzyme activity, as enzyme activity is sensitive to temperature and pH. D D. To increase the activation energy of the reaction.

A A. Increases Km, decreases Vmax. B B. Decreases Km, increases Vmax. C C. Increases Km, no change in Vmax. D D. No change in Km, decreases Vmax.

A A. The substrate of the enzyme inhibits the enzyme's activity. B B. The product of a metabolic pathway inhibits an enzyme early in the pathway. C C. An activator molecule enhances the enzyme's activity. D D. Enzymes are activated by their own products.

A A. Increases Km, decreases Vmax. B B. Decreases Km, increases Vmax. C C. Increases Km, no change in Vmax. D D. No change in Km, decreases Vmax.

A A. Hydrolases. B B. Isomerases. C C. Oxidoreductases. D D. Transferases.

A A. Sterilization of medical equipment. B B. Production of antibiotics. C C. Tenderizing meat and clarifying fruit juices. D D. Diagnosis of genetic disorders.

A A. The process of destroying enzyme activity. B B. The process of isolating enzymes from cells. C C. The process of confining enzymes to a solid support or within a defined space. D D. The process of purifying enzymes to homogeneity.

A A. Active site. B B. Catalytic site. C C. Allosteric site. D D. Binding site.

A A. The maximum rate of reaction at infinite substrate concentration. B B. The substrate concentration at which the reaction rate is half of Vmax. C C. The equilibrium constant for the enzyme-substrate complex formation. D D. The rate constant for the conversion of substrate to product.

A A. Increases Km, decreases Vmax. B B. Decreases Km, decreases Vmax. C C. Increases Km, no change in Vmax. D D. No change in Km, decreases Vmax.

A A. To provide structural support to the enzyme only. B B. To participate in redox reactions only. C C. To act as cofactors, participating in substrate binding, active site stabilization, or redox reactions. D D. To regulate gene expression of the enzyme.

A A. It decreases the reaction rate. B B. It increases the reaction rate. C C. It has no effect on the reaction rate. D D. It initially increases then decreases the reaction rate beyond an optimal temperature.

A A. By increasing the activation energy of the reaction. B B. By decreasing the activation energy of the reaction. C C. By increasing the temperature of the reaction. D D. By decreasing the temperature of the reaction.

A A. To break down molecules into smaller units. B B. To build larger molecules from smaller units. C C. To rearrange atoms within a molecule. D D. To transfer functional groups between molecules.

A A. To provide structural support to the enzyme. B B. To directly bind to the active site and block substrate binding. C C. To act as carriers of electrons or functional groups in enzymatic reactions. D D. To regulate enzyme production at the genetic level.

A A. pH changes only affect substrate concentration, not the enzyme itself. B B. pH changes can alter the enzyme's three-dimensional structure and ionization state of amino acid residues in the active site. C C. pH only affects the rate of diffusion of substrates to the enzyme. D D. pH changes the temperature of the reaction mixture.

A A. Bond cleavage with the addition of water. B B. Bond cleavage through oxidation. C C. Bond cleavage to form double bonds or rings. D D. Bond cleavage by transferring functional groups.

A A. The enzyme is used to treat a disease directly. B B. The enzyme's presence or concentration in body fluids indicates a particular physiological state or disease. C C. The enzyme is used to synthesize drugs in the body. D D. The enzyme is used to clean medical instruments.

A A. Enzymes are generally specific for the type of reaction but not for the substrate. B B. Enzymes are generally specific for the substrate but not for the type of reaction. C C. Enzymes exhibit specificity for both the type of reaction catalyzed and the substrate(s) involved. D D. Enzymes are not specific and can catalyze a wide range of reactions with different substrates.

A A. Lyases. B B. Ligases. C C. Transferases. D D. Hydrolases.