Campbell Chapter 5 Questions 

Connecting the Concepts

1. Molecules move across membranes by: passive transport and active transport

   1. Passive transport may be diffusion of small nonpolar molecules or facilitated diffusion of polar molecules and ions

   2. Active transport uses transport proteins and requires ATP

   3. Passive transport moves down the concentration gradient

   4. Active Transport moves against the concentration gradient

2. Which best describes the structure of a cell membrane: proteins embedded in a bilayer of phospholipids

3. A plant cell placed in distilled water will become turgid

4. an animal cell placed in distilled water will burst

5. The sodium concentration in a cell is ten times less than the concentration in the surrounding fluid. How can the cell move sodium out of the cell: Active Transport because active transport works against the concentration gradient

6. Facilitated Diffusion across a membrane requires: transport proteins

7. Facilitated Diffusion moves a solute down its concentration gradient

8. What are aquaporins: Aquaporins are transport proteins or channels that facilitate the diffusion of water across a lipid membrane.

9. Where would you expect to find aquaporins: Aquaporins are needed where water is diffused often, such as plant cells, red blood cells, and kidney cells.