Enzyme Graphs

A group of students conducts research on enzyme activity and collects the data shown in the graphs. Which statement is supported by the evidence in the graphs?

• The enzyme is very active at approximately 42°C and within a pH range of 2 to 6. 

• The enzyme functions well at a temperature of 35°C and would be active at any pH value.

• The enzyme works best in a pH range of 6 to 8 and at a temperature of approximately 37° C.

• The enzyme's activity is greatest at pH 7 and would not be affected by a change in temperature.

An enzyme is a special kind of catalyst. How does it work?

• It speeds specific chemical reactions.

• It breaks down and takes part in chemical reactions to form new products.

• It slows down specific chemical reactions.

• It triggers chemical reactions at any pH or temperature.

According to the graph, at which temperature do the two enzymes have about the same amount of activity?

• 25 degrees

• 47 degrees

• 57 degrees

• 93 degrees

A digestive enzyme turns starch into sugar. This is an example of

• larger molecules being broken down into smaller molecules.

• liquid being absorbed and a solid being created.

• smaller particles joining and forming a larger molecule.

• a solid being dissolved by a liquid.

The graph below shows the effect of temperature on enzyme X's relative rate of action on a protein. What effect does the temperature have on enzyme X in the range of 55°C to 68°C?

• It denatures the enzyme and increases its ability to increase the rate of the reaction.

• It improves the enzyme's chemical structure and increases its affinity for the substrate.

• It denatures the enzyme and decreases its ability to increase the rate of the reaction.

• It improves the enzyme's chemical structure and decreases its affinity for the substrate.

Pick three correct statements about enzymes.

• Enzymes are composed of chains of amino acids.

• Enzymes are changed as a result of a reaction.

• Enzymes have a specific shape.

• Enzymes are destroyed when they are used.

• Enzymes temporarily associate with a reactant.

Which of the following statements about enzymes is true?

• Enzymes work best at a specified pH.

• Enzymes are not affected by temperature changes.

• Enzymes are complex carbohydrates.

• Enzymes are inorganic chemical molecules.

How do enzymes affect the reactions in living cells?

• Enzymes change the active site energy of the reaction.

• Enzymes slow the speed of the reaction.

• Enzymes change the temperature of the reaction.

• Enzymes lower the activation energy of the reaction.

A change in the rate of enzyme action in aquatic invertebrates would most likely result from a change in which of the following?

• the number of producers in the water

• the number of consumers in the water

• the salt content of the water

• the temperature of the water

Enzyme B helps in the process of breaking molecule A into molecules C and D.

The enzyme becomes denatured, as shown below. Which of the following outcomes can be expected?

• The enzyme will be able to convert molecule A into molecules C and D at a faster rate.

• The enzyme will be able to reverse the reaction, combining molecules C and D into molecule A.

• The enzyme will only be able to convert molecule A into molecules C and D a few more times.

• The enzyme will no longer be able to aid in the reaction that breaks molecule A into molecules C and D.