WorksheetsEnzymes STAAR Questions
Total questions: 13
Worksheet time: 7mins
Rennin is an enzyme that catalyzes a reaction that solidifies milk. Rennin was added to three different test tubes with milk. Each test tube was placed in a water bath for ten minutes. The data collected from the experiment is shown. Which statement best explains the result of test tube 3?
The enzyme changed the product.
The substrate was used up.
The enzyme was denatured.
The substrate reacted with the enzyme.
The function of an enzyme in a biochemical reaction is to—
raise the temperature of the system
speed up the rate of the reaction
increase the amount of substrate added
change the type of product formed
A model of an enzyme and its corresponding substrate is shown. Substrate (dark shape) Enzyme (light shape) Which model best represents the molecules at the end of the reaction?
For an enzyme to be able to catalyze a reaction, the active site must—
be occupied by an inhibitor
increase the activation energy level
have a complementary shape to the substrate
cause the enzyme to be destroyed in the reaction
Enzymes are proteins that have a three-dimensional shape that is specific to a particular substrate. Environmental conditions can change the shape of the protein. What is the most likely result if the shape of the enzyme changes?
The substrate will change its shape to match the enzyme.
The enzyme will no longer be able to catalyze the reaction with the substrate.
The products made from the enzyme and the substrate will be changed.
The enzyme will be able to bind to more diverse substrates than before.
The graphs show the reaction rate for an enzyme across a range of temperatures and pH. Enzyme Reaction Rates Based on these data, this enzyme functions best at what temperature and pH?
Temperature of 27°C and a pH of 4
Temperature of 37°C and a pH of 6
Temperature of 40°C and a pH of 8
Temperature of 50°C and a pH of 10
Which statement about enzyme activity is best supported by this graph?
An enzyme must be composed of multiple polypeptides, or subunits, to be active.
An enzyme’s rate of activity increases with time until it becomes inactive.
An enzyme functions best under specific temperature conditions.
An enzyme works equally well in bacteria that are adapted to high temperatures and in eukaryotic cells such as human cells.
Some foods that are rich in complex carbohydrates can be difficult to digest. Gas often forms as the foods are slowly digested by bacteria in the large intestine. The advertisement is for a nutritional supplement that prevents intestinal gas. Which of the following represents evidence that could be used to support the claims about this product?
Complex carbohydrates are found in vegetables and grains, which are good sources of fiber, vitamins, antioxidants, and minerals. Vegetables and grains are known to reduce the risk of heart disease.
Some nutritional supplements provide vitamins and minerals that are missing from a person’s diet. These types of nutritional supplements contain important nutrients that reduce the risk of malnutrition.
Consuming enzymes specific for carbohydrate digestion helps the body digest complex carbohydrates more quickly in the stomach and small intestine.
Some nutritional supplements add beneficial bacteria to a person’s diet. These bacteria populate the stomach and prevent carbohydrate digestion.
Which statement explains the effect of an inhibitor on an enzyme?
A substrate will be able to bond with the enzyme.
The enzyme will likely be attacked by immune cells.
The enzyme will be unable to produce more enzymes.
A substrate will be unable to attach to the enzyme.
People who have Alzheimer’s disease experience an increasing loss of brain function and cognition over time. Alzheimer’s is characterized by a buildup of abnormal protein fragments that damage brain cells. Recently scientists have discovered an enzyme, BACE2, that decreases these abnormal protein fragments in the brain of a person with Alzheimer’s disease. Which statement explains how BACE2 most likely works?
BACE2 breaks down into smaller pieces that react with the abnormal protein fragments, forming more complex molecules.
BACE2 speeds up the reaction that breaks down the abnormal protein fragments.
BACE2 molecules link several abnormal protein fragments together, forming a complete protein.
BACE2 is a reactant that combines with the abnormal protein fragments.
Fireflies emit light. The production of light by an organism is called bioluminescence. To generate visible light, cells in a firefly’s tail produce thousands of luciferase enzymes. Luciferase binds to a chemical called luciferin. Once bound, the luciferase enzyme speeds up a chemical reaction that combines an oxygen molecule and luciferin to produce oxyluciferin. This reaction requires energy and releases light. Which of the following best describes how the luciferase enzyme speeds up the chemical reaction?
Luciferase increases the amount of time the light is visible.
Luciferase decreases the amount of energy required for the reaction to start.
Luciferase increases the number of sites on luciferin that must bind to oxygen.
Luciferase decreases the temperature of the environment inside the body of the firefly.
Pepsin and trypsin are two of the digestive enzymes that break down protein. A group of students studied the pH requirements of these enzymes. The graph below shows the results. The students found that pepsin functions best in an acid environment and trypsin functions best in a neutral environment. Based on their observations, pepsin most likely aids in digestion in which part of the human body?
Pancreas
Intestines
Mouth
Stomach
Enzymes are proteins that help increase the rate of chemical reactions inside cells. These proteins are composed of many simpler molecules called amino acids. Which of the following suggests that the shape of an enzyme determines the enzyme’s function?
Enzymes are specific to a substrate.
Enzymes can operate in a wide range of conditions.
Enzymes are activated by neighboring molecules.
Enzymes can be found in all life-forms.
