Domain 1 Post Review Practice

Which THREE statements BEST describe proteins? (SB1c)

• Proteins aid in chemical reactions.

• Proteins are long, folded chains of amino acids.

• Proteins are bonded together to form simple sugars.

• The shape of a protein molecule determines its function.

• Proteins can be used for long-term energy storage.

Answer explanation

Choice A is correct because many proteins are enzymes that can help speed up chemical reactions in cells.

Choice B is correct because the sequence of amino acids tells the protein how to fold.

Choice D is correct because how a protein is folded tells the protein which function to perform.

Which TWO statements describe a similarity between Investigation 1 and Investigation 2? (SB1d)

• In both investigations, energy is not required to move the molecules. 

• In both investigations, molecules pass through a semipermeable membrane. 

• In both investigations, molecules move against their concentration gradient.

• In both investigations, molecules move from areas of high to low concentration. 

• In both investigations, ATP is required to move molecules across the membrane.

Answer explanation

Energy in the form of ATP is not required to move the molecules in either investigation.

In both investigations, the molecules move from highly concentrated areas to areas of low concentration. 

The graph shows the effect of temperature on Enzyme X's rate of action on a protein. Which THREE actions would affect Enzyme X's rate of action? (SB1c)

• a decrease in temperature from 40 degrees Celsius to 10 degrees Celsius

• the addition of more protein at 80 degrees Celsius

• the addition of cold water when the reaction is at 50 degrees Celsius

• the removal of the protein when the reaction is at 30 degrees Celsius

• the addition of more protein at 0 degrees Celsius

Answer explanation

Choice A is correct because decreasing the temperature from 40 to 10 degrees Celsius would cause a decrease in the rate of reaction because the enzyme has optimal functioning at 50 degrees Celsius. 

Choice C is correct because the addition of cold water when the reaction is at 50 degrees Celsius.

Choice D is correct because the removal of the protein when the reaction is at 30 degrees Celsius.

The table below shows the direction and function of substances in a chemical reaction that takes place in the chloroplasts of plant cells. The table is missing a title and information at W, X, and Y.

What is the direction, X, and function, Y, for the sugar molecules? (SB1e)

• Direction X is out; function Y is to provide chemical energy for the plant cell.

• Direction X is in; function Y is to provide heat energy for the plant cell.

• Direction X is out; function Y is to form more chlorophyll for the plant cell.

• Direction X is in; function Y is to form large sugar molecules for the plant cell.

The following question has two parts. First, answer Part A. Then, answer Part B.

Part A: A student places cells of Elodea, a freshwater plant, on a wet-mount microscope slide. The student uses a saltwater solution to prepare the slide. When the cells are viewed under the microscope, what is the student MOST LIKELY to see?

Part B: Which BEST supports the choice from Part A? (SB1d)

• Part A: The cells will shrink within the cell walls. 

  Part B: The cells will lose water to the surrounding solution because the solution's solute concentration is higher than the cell's solute concentration.

• Part A: The cells will swell, expanding the cell walls. 

  Part B: The cells will attempt to maintain homeostasis by dissolving their cell walls to quicken the process of osmosis. 

• Part A: The cell walls will dissolve, releasing the cell.

  Part B:  The cells will gain water from the surrounding solution because the solution's solute concentration is higher than the cell's solute concentration. 

• Part A: The cells will not be affected and remain unchanged. 

  Part B: The cells will attempt to maintain homeostasis by remaining unchanged and unaffected by their surroundings. 

Answer explanation

Part A: The cells will attempt to reach equilibrium by excreting water into their surroundings, causing the cells to shrink. 

Part B: The cells will attempt to reach equilibrium by excreting water from an area of high concentration to low concentration, causing the cells to lose water and shrink.