QUESTION 1Enzymes (Check all that apply.)are inorganic molecules.act as catalysts.have a special shape that controls their functionare specific for their substrates.QUESTION 2Enzymes are consumed in chemical reactions and must therefore be replenished True FalseQUESTION 3Which of the following best describe what enzymes are and how they are used? catalytic proteins that are efficient in initiating chemical reactions by lowering the activation energy.catalytic lipids that are efficient in initiating chemical reactions by lowering the activation energy.intermediate carriers of electrons that are required for, or increase the rate of, catalysis.organic substances that increase the activation energy.QUESTION 4Altering the three-dimensional structure of an enzyme might change the amount of energy needed for a reaction.allow the reaction to occur at a faster rate.change the type of substrate that binds the enzyme's active siteprevent the substrate from binding the enzyme's active site.QUESTION 5Imagine that you are observing an enzyme-catalyzed reaction in lab. Every time you add more enzyme, the reaction rate increases proportionally until the reaction rate suddenly levels off. No other chemicals were added, and no modifications were made in the experimental setting. Why do you think the reactionn rate stopped increasing? @ As a reaction rate increases, eventually all available substrate molecules will be bound to enzymes, or all available enzymes will be bound to substrate. The reaction will be substrate-limited or enzyme-limited. When all available molecules of either enzyme or substrate are bound, saturation occurs, and at this point the reaction rate will level off. To keep increasing the reaction rate, the levels of available substrate or enzyme must increase. In the above example, additional enzyme was added, so substrate must have been the limiting factor.The molecules of substrate noncompetitively inhibited the enzyme.The enzymes were denatured.The molecules of substrate were all bound to enzyme.The molecules of product competitively inhibited the substrate.QUESTION 6As the amount of substrate is increased in an enzyme-substrate reaction, the amount of enzyme also increases proportionally.enzymes work faster.the amount of product increases.enzymes become denatured faster.QUESTION 7A given enzyme works on any number of different substratesone of two possible substratesone type of substrate.no substrateQUESTION 8_________ can change the active site of an enzyme and alter its functionconcentration of the substrateonly pHtemperature and pHconcentration of the enzymeQUESTION 9The pH can affect the activity of an enzyme controlled reaction by (Check all that apply) affecting hydrogen bonding.changing the shape of the enzymes active site.altering the allosteric site.changing the ionic state of either the enzyme or the substrate.QUESTION 10The two data curves on the figure illustrate that optimal temperature ranges are not the same for all enzymespH is not related to enzyme efficiencytemperature ranges are not the same for all enzyme activity. temperature is not related to enzyme efficiency. QUESTION 11The active site of an enzyme (Check all that apply) is the part that binds to the substrate.is the part that is permanently altered by the reaction.changes to conform to the substrate.is compatible with many different substrates, depending on the situation.QUESTION 12How does an enzyme work to catalyze a reaction? It supplies the energy to speed up a reaction.lowers the energy barrier needed for reactants to achieve the transition state or lowers the energy of activation of a reaction.It lowers the energy barrier needed for reactants to achieve the transition state.It lowers the energy of activation of a reaction.QUESTION 13The shape of an enzyme determines its function. True FalseQUESTION 14An increase in enzyme or substrate concentration will not change the amount of product producedinterfere with the reaction.increase the amount of reaction.decrease the amount of reaction.QUESTION 15How can you determine the optimum pH of an enzyme? Test the enzyme at different pH levels.Use a pH meter.Test the enzyme in vinegar, orange juice and saliva only.Test the enzyme in distilled water only.QUESTION 16Enzyme activity can be determined in the following ways: by measuring how much of the substrate is consumeddetermining when the amount of substrate is equal to the amount of productby measuring how much of the enzyme is consumedby measuring how much of the product is producedQUESTION 17As the concentration of an enzyme increases for a given substrate, the reaction rate increases similarly.the turnover number decreases at the same rate that the enzyme concentration increases.the rate of the reaction decreases to a pointthe reaction stops.QUESTION 18Enzymes are proteins. nucleic acidslipids. carbohydrates. QUESTION 19Catalase activity can be determined by measuring the formation of oxygen gas.measuring the formation of hydrogen peroxide.measuring the ratio of catalase to oxygen.measuring the amount of catalase remaining in the chemical reaction.QUESTION 20How does the concentration of the substrate in an enzyme-controlled chemical reaction change over time? The substrate concentration will not change.The substrate concentration will decrease at first, then it will increase.The substrate concentration will decrease.The substrate concentration will increase.QUESTION 21Check all of the following statements that are true. The enzyme changes shape to fit the substrate.The enzyme helps to break bonds in the substrateThe enzyme helps to create bonds between two substrates.The substrate changes shape to fit the enzyme.QUESTION 22What may affect the rate of an enzyme-driven reaction? (Check all that apply.)@ Altering any of these variables may make an enzyme function less than optimally.concentration of substratethe air pressurepHtemperatureQUESTION 23In a catalase controlled experiment, the negative control can be shown by catalase onlya mixture of water and catalase.a mixture of hydrogen peroxide and water.a mixture of hydrogen peroxide and catalase.QUESTION 24The primary function of an enzyme or any biological catalyst is to reduce the energy of activation of a reaction.reduced the energy of activation and increase the rate of a reaction.change the direction of a reaction.increase the rate of a reaction.QUESTION 25In a catalase controlled experiment, the specificity of catalase can be shown by comparing a mixture of hydrogen peroxide and catalase.a mixture of water and catalase.a mixture of hydrogen peroxide and water.hydrogen peroxide alone.