Enzymes

Base your answer to the following question on the diagram below, which represents a chemical reaction that occurs in the human body, and on your knowledge of biology. Which statement describes a characteristic of molecule Z?

• Molecule Z will function at any temperature above 20°C.

• Molecule Z is composed of a string of molecular bases represented by A, T, G, and C.

• Molecule Z will function best at a specific pH.

• Molecule Z is not specific, so this reaction can be controlled by any other chemical in the body.

Luciferin is a molecule that, when broken down in fireflies, produces heat and light. The rate at which luciferin is broken down in cells is controlled by

• a carbohydrate

• a simple sugar

• an enzyme

• a complex fat

Lipase, maltase, and protease are members of a group of catalysts known as

• enzymes

• hormones

• carbohydrates

• fats

Although a certain molecule is involved in a specific reaction, its structure and chemical composition are exactly the same after the reaction as before the reaction. This molecule is most likely classified as

• an enzyme

• a salt

• a sugar

• an acid

Compound X increases the rate of the reaction shown below. Compound X is most likely

• an enzyme

• a lipid molecule

• an indicator

• an ADP molecule

Tags

NGSS.HS-PS1-2

Meat tenderizer contains an enzyme that interacts with meat. If meat is coated with tenderizer and then placed in a refrigerator for a short time, how would the enzyme be affected?

• It would be broken down.

• Its activity would slow down.

• Its shape would change.

• It would no longer act as an enzyme.

The graph below shows the effect of temperature on the relative rate of action of enzyme X on a protein.

• the addition of cold water when the reaction is at 50°C

• an increase in temperature from 70°C to 80°C

• the removal of the protein when the reaction is at 30°C

• a decrease in temperature from 40°C to 10°C

Enzymes have an optimum temperature at which they work best. Temperatures above and below this optimum will decrease enzyme activity. Which graph best illustrates the effect of temperature on enzyme activity?

• A- Graph showing a linear decrease in enzyme activity with increasing temperature.

• B- Graph showing a peak in enzyme activity at an optimum temperature.

• C- Graph showing a linear increase in enzyme activity with increasing temperature.

• D- Graph showing a sigmoidal increase in enzyme activity with increasing temperature.

Pepsin works best in which type of environment?

• acidic, only

• basic, only

• neutral

• sometimes acidic, sometimes basic

Neither enzyme works at a pH of

• 1

• 5

• 3

• 13