Macromolecules, Enzymes, & Cell Structures

1.

Multiple Choice

30 sec

1 pt

Marcus is stranded on an island that only has grass. He begins to run low on energy, so he decided to eat the grass knowing that it contains cellulose, as sugar (carbohydrate). However, humans cannot digest the cellulose. Which answer best explains why he cannot break down cellulose, and what the result would be if he could?

Marcus is missing the substrate that bind with cellulose; if he had it he could break down the grass for long-term energy.

Marcus is missing the enzyme (cellulase) that breaks down cellulose; if he had it he could break down the cellulose for short-term energy.

Marcus is missing the substrate that binds with cellulose; if he had it he could break down the cellulose for short-term energy

John is missing the enzyme (cellulase) that breaks down cellulose; if he had it he could break down the grass for long-term energy.

2.

Multiple Choice

30 sec

1 pt

Which of the following will most likely change when an enzyme is added to a reaction?

the rate of the reaction

the pH of the reaction

the products of the reaction

the temperature of the reaction

3.

Multiple Choice

30 sec

1 pt

What does it mean for a protein to be denatured?

The protein is removed from its original environment and placed into a different, more suitable environment.

To modify the protein to make it a better structure.

To cause the structure of a protein to unfold and to change shape, making it unable to do its job.

To make a protein speed up the chemical reaction.

4.

Multiple Choice

30 sec

1 pt

The graph above how the activity of an enzyme changes over a range of pH values. Which of the following conclusions is supported by the data?

The optimum pH of the enzyme is 1.0

The optimum pH of the enzyme is 2.0

The enzyme's activity is greater around pH of 4 than around pH of 1

The enzyme's activity continually increases as pH increases from 1.0 to 6.0

5.

Multiple Choice

30 sec

1 pt

The role of an enzyme in a chemical reaction is to change which of the following?

the type of reaction that occurs

the pH at which the reaction occurs

the activation energy of the reaction

the temperature at which the reaction occurs

6.

Multiple Choice

30 sec

1 pt

Plant species such as the sesame plant and the coconut palm have large amounts of lipids in their seeds. Which of the following is the most likely function of these lipids?

to store energy for the seedlings

to absorb water for the seedlings

to encode most of the genetic information in the seedlings

to speed up most of the chemical reactions in the seedlings

7.

Multiple Choice

30 sec

1 pt

The main function of the cell wall is to

help the cell move

store DNA

direct the activities of the cell

support and protect the cell

8.

Multiple Choice

30 sec

1 pt

Students in a science class were asked to investigate how missing or damaged organelles affect cellular homeostasis. Which of the following questions should they ask if they are investigating the importance of the ribosome? (Hint: think about what ribosomes make)

Which organelle would most likely be affected first if there was no glucose present to convert energy for cellular needs?

Which organelle would most likely be affected if there were no amino acids for building proteins present in the cell?

Which organelle would most likely be affected if there no enzymes present to digest old and damaged parts of the cell?

Which organelle would most likely be affected if there was no sunlight available to convert solar energy into chemical energy?

9.

Multiple Choice

30 sec

1 pt

Which of the following is the best explanation of how one organelle in a cell directly supports the work of another organelle to maintain cellular homeostasis within a plant cell?

Chloroplasts and the mitochondria benefit from breaking down proteins for immediate energy

Mitochondria produce energy molecules which are digested by the lysosomes to provide energy for the cell

Chloroplasts convert solar energy into simple sugars which are often then used by the mitochondria to provide energy for the cell

Golgi bodies sort, refine, and repackage lipids used by the smoother ER when making proteins

10.

Multiple Choice

30 sec

1 pt

A student is preparing for a track meet to be held next day. He needs to pick a that small meal that has macromolecules that provide quick energy without much fat or not too high in excess calories. Two different snack options are shown. What is the BEST option for this student?

The chicken (option a) because it has the greatest amount of fat, which provides a quick source of energy for cells.

The chicken (option a) because it has the greatest amount of carbohydrates, which provides a quick energy source for cells.

The pasta (option b) because it has the greatest amount of carbohydrates, which provides a quick energy source for cells.

The pasta (option b) because it has the greatest amount of fat and protein, which provides a quick source of energy for cells.

11.

Multiple Choice

30 sec

1 pt

Glyphosate is a chemical used in herbicides to kill plants. Glyphosate works by stopping the production of amino acids. Which of the following statements provides the best explanation for how glyphosate most likely kills plants?

Glyphosate stops the production of amino acids which prevents the ribosomes from making proteins.

Amino acids are the main component of the cell wall of a plant and without amino acids the plant no longer has support and structure.

Lysosomes are responsible for cellular digestion and without amino acids there is not food for the lysosome to digest.

Without amino acids the cell lacks its main source of quick energy and the mitochondria may no longer make energy for cellular processes.

12.

Multiple Choice

30 sec

1 pt

White blood cells contain digestive enzymes to aid in fighting infection in the body. When a white blood cell comes across a foreign body of matter, it will bring the bacteria into the cell and break it down into waste. Which organelle within the white blood cell is responsible for this function?

mitochondria

vacuoles

ribosomes

lysosomes

13.

Multiple Choice

30 sec

1 pt

A student is constructing a model to show how catalase, and enzyme, breaks down hydrogen peroxide into water and oxygen. The chemical reaction is shown below:

catalase

hydrogen peroxide -------------> oxygen + water

Which model below BEST represents the reaction that takes place with the catalase enyzme?