AP Biology : Enzymes
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Example Questions
Example Question #31 : Enzymes
Which of the following would be an example of a catalyst?
Enzymes
ATP
Chloroplasts
Mitochondria
Enzymes
Enzymes are proteins that act as catalysts for reactions. Enzymes are essential in enabling the proper function of human metabolism. If enzymes were absent then chemical traffic throughout the metabolic pathways would become backed up.
Example Question #32 : Enzymes
Enzymes are a type which of the following categories?
Metabolite
Catalyst
Energy source
Sugar
Catalyst
Enzymes are catalytic proteins. Enzymes are essential in proper functioning of metabolism because without them chemical traffic throughout the metabolic pathways would become backed up.
Example Question #31 : Enzymes
Enzymes are a type of which of the following organic molecules?
Protein
Sugar
Lipid
Carbohydrate
Protein
Enzymes are proteins that act as catalysts for metabolism. Enzymes are essential in proper functioning of metabolism because without them chemical traffic throughout the metabolic pathways would become backed up.
Example Question #21 : Understand Enzyme Structure And Purpose
Which of the following terms can be defined as the initial investment of energy in a reaction that is required to break bonds in the reactant molecules?
Reaction energy
Consumed energy
Activation energy
Initiation energy
Activation energy
The investment of energy required to start a reaction is called the free energy of activation or activation energy. Activation energy is usually in the form of heat from the surrounding area that molecules in the reaction absorb.
Example Question #22 : Understand Enzyme Structure And Purpose
Proteins engage in all of the following functions except __________.
transport substances into and/or out of cells
comprise muscle tissue
store energy in adipose cells
control the rate of reactions and regulate cell processes
store energy in adipose cells
Proteins can control rates of reaction and regulate cell processes, form muscle tissue, and transport substances into and out of cells. They do not store energy in fat cells.
Example Question #36 : Enzymes
What does an enzyme do to the activation energy of a given reaction?
Enzymes provide the activation energy for reactions
Enzymes do not change the activation energy
Enzymes lower the activation energy
Enzymes raise the activation energy
Enzymes lower the activation energy
Enzymes lower the activation energy in chemical reactions in cells. They do not alter the composition of products of chemical reactions.
Example Question #37 : Enzymes
What are the reactants of enzyme-catalyzed reactions known as?
Enzymes
Substrates
Inhibitors
Products
Substrates
The reactants of enzyme-catalyzed reactions are known as substrates. Enzymes catalyze formation of products from their substrates. Inhibitors hinder the efficacy of enzymes, thereby decreasing the rate of reactions, and nucleotides are the monomers of DNA and RNA.
Example Question #23 : Understand Enzyme Structure And Purpose
Which of the following statements regarding exergonic reactions is true?
They do not require energy input before the reaction proceeds
The energy released cannot be used to perform work
The products contain less energy the reactants
They usually occur instantaneously
They release energy in the form of noise
The products contain less energy the reactants
The correct answer to this question is the products contain less energy the reactants.
The products indeed do contain less energy than the reactants because when a spontaneous reaction occurs, it releases energy, which is used to do work. Energy is released in the form of ATP and heat, not noise. Also an input of energy is required before the reaction proceeds, otherwise the reaction does not proceed.
Example Question #24 : Understand Enzyme Structure And Purpose
How do enzymes increase reaction rates?
Decreasing activation energy
Increasing pH
Increasing activation energy
Increasing temperature
Decreasing activation energy
Enzymes increase the rate of reactions through stabilizing the transition state, which decreases activation energy.
Example Question #25 : Understand Enzyme Structure And Purpose
Which of the following does not affect enzyme activity?
substrate concentration
All of the above
pH
temperature
All of the above
pH and temperature affect enzyme activity, as there is an optimal pH and temperature for each enzyme, and a pH or temperature too far from the optimal level can cause the enzyme to denature. Substrate concentration affects enzyme activity; increasing substrate concentration will increase the rate of reaction to the point that the enzymes are saturated.
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