Unit 2 Exam Review

If ATP breakdown (hydrolysis) is inhibited, which of the following types of movement across cell membranes is also inhibited?

• Movement of oxygen into a cell

• Movement of water through aquaporins

• Passage of a solute against its concentration gradient

• Facilitated diffusion of a permeable substance

A common laboratory investigation involves putting a solution of starch and glucose into a dialysis bag and suspending the bag in a beaker of water, as shown in the figure below.

The investigation is aimed at understanding how molecular size affects movement through a membrane.

Which of the following best represents the amount of starch, water, and glucose in the dialysis bag over the course of the investigation?

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• 
• 
• 

Cystic fibrosis is a recessively inherited disorder that results from a mutation in the gene encoding CFTR chloride ion channels located on the surface of many epithelial cells. As shown in the figure, the mutation prevents the normal movement of chloride ions from the cytosol of the cell to the extracellular fluid. As a consequence of the mutation, the mucus layer that is normally present on the surface of the cells becomes exceptionally dehydrated and viscous.

An answer to which of the following questions would provide the most information about the association between the CFTR mutation and the viscous mucus?

• Is the mucus also secreted from the cells through the CFTR proteins?

• How does the disrupted chloride movement affect the movement of sodium ions and water by the cell?

• How does the mutation alter the structure of the CFTR proteins?

• What is the change in nucleotide sequence that results in the CFTR mutation?

Tags

NGSS.HS-LS3-2

You are a farmer growing crops. The concentration of your potatoes are 0.35M and you are advised to water your plants with a 0.35M saline solution to provide nutrients. What happens to the plant cells?

• Cells are normal since this is an isotonic solution.

• Cells become flaccid since this is an isotonic solution.

• Cell become plasmolyzed since this is an isotonic solution.

You are a doctor. A patient comes in dehydrated. What type of solution would be best to place into their IV?

• A hypotonic solution to allow the cells to rehydrate.

• A slightly hypertonic solution to allow the cells to rehydrate.

• An isotonic solution to increase fluid in the body without causing harm to the cells.

• An isotonic solution to decrease fluid in the body without causing harm to the cells.

Which of the following describes an appropriate water movement pathway?

• hypotonic solution to hypertonic solution

• hypertonic solution to hypotonic solution

• hypertonic solution to isotonic solution

• isotonic solution to hypotonic solution

What is the difference between the molecule transported in facilitated diffusion versus simple diffusion?

• facilitated diffusion involves nonpolar solute transport through a membrane protein

• simple diffusion involves nonpolar solute transport through a membrane protein

• facilitated diffusion involves polar solute transport through a membrane protein

• simple diffusion involved polar solute transport through a membrane protein

Which of the following describes the difference between passive and active transport?

• passive transport involves moving solutes against the concentration gradient using ATP.

• active transport involves moving solutes against the concentration gradient using ATP.

• passive transport involves moving solutes with the concentration gradient using ATP.

• active transport involves moving solutes with the concentration gradient using ATP.

Which of the following describes the difference between channel and carrier transport proteins?

• channel proteins bind to solute to shuttle the solute across the membrane

• channel proteins provide a nonpolar channel through the membrane

• carrier proteins bind to solute to shuttle the solute across the membrane

• carrier proteins provide a nonpolar channel through the membrane

Describe what would happen if you placed an animal cell in 1.0 M solution.

• The cell would lyse

• The cell would be flaccid

• The cell would shrivel

• The cell would be normal

Tags

NGSS.HS-LS1-3