Unit 2 Practice Test: Biochemistry

The graph to the left shows the progress of a chemical reaction performed under two separate conditions.

Which of the following lines represents the activation energy (Ea) for the UNCATALYZED reaction?

• 1

• 2

• 3

The graph to the left shows the progress of a chemical reaction performed under two separate conditions.

Which of the following lines represents the activation energy (Ea) for the CATALYZED reaction?

• 1

• 2

• 3

The graph to the left shows the progress of a chemical reaction performed under two separate conditions.

Which of the following statements best describes the term activation energy?

• The minimum amount of energy required to start a chemical reaction and convert reactants to products.

• The minimum amount of energy required to start a chemical reaction and convert products to reactants.

• The amount of energy required for a substrate to bind to the active site of an enzyme.

• The amount of energy required for the product of a reaction to detach from the active site of an enzyme.

The graph to the left shows the progress of a chemical reaction performed under two separate conditions.

Which statement is true of BOTH the uncatalyzed and catalyzed reaction pathway?

• These reactions are endothermic because they had to absorb energy to start the process.

• These reactions are exothermic because energy is released as the products are formed.

• These reactions are endothermic because the products have less energy than the reactants.

• These reactions are exothermic because the reactants have less energy than the products.

The graph to the left shows the progress of a chemical reaction performed under two separate conditions.

Which statement is true of the reaction represented by the dotted - - - line?

• That reaction is occurring at a higher temperature.

• That reaction is occurring at a lower pH.

• That reaction is occurring at a slower rate.

• That reaction is occurring in the presence of a catalyst, such as an enzyme.

Using the potential energy graphs below, showing the progress of chemical reactions, which graphs shows a release of energy from reactants to products?

• Graph A

• Graph B

• Neither graph because both reactions require activation energy to be absorbed to start.

• Both graphs because both reactions release energy from the highest point in the graph to the lowest point.

The diagram below show the chemical structure of a macromolecule.

Based on the structure of this macromolecule, select THREE (3) correct statements from the list below.

• This is the structure of a carbohydrate

• This is the structure of a lipid

• This molecule is used for long-term energy

• This molecule is stored in the cell walls of plants

• This molecule can be used for energy, insulation, and protection.

The graph shows the results of adding substrate to a solution that contains 10 grams of enzyme. At which substrate concentration are all of the enzyme molecules working at their maximum rate (all active sites are binded)?

• 10 mg/L

• 20 mg/L

• 30 mg/L

• 40 mg/L

According to the graph below, which statement is true?

• This graph represents an endergonic reaction.

• C + D are enzymes that lower the activation energy.

• C+ D are reactants.

• This graph represents an overall release of energy.

According to the graph below, which statement is true?

• The energy of the reactants is 20 kJ.

• The energy of the reactants is 40 kJ.

• The energy of the products is 60 kJ.

• The energy of the products is 100 kJ.