BIOL 103 ch.5

2. Which statement is true of plasma membranes? a. They have molecules on their surfaces that identify them b. They are essentially impermeable c. They are basically static, non changing structures d. They are hydrophilic barriers between cells e. They function primarily through the activity of their carbohydrates

a. They have molecules on their surfaces that identify

12. Which structure can contain over 40 different digestive enzymes and is part of the endomembrane system of the cell? a. Golgi body b. Lysosome c. Endoplasmic reticulum d. mitochondra

b. Lysosome

9. Which statement is true? a. A cell placed in an isotonic solution will swell b. A cell placed in a hypotonic solution will swell c. A cell placed in a hypotonic solution will shrink d. A cell placed in a hypertonic solution will remain the same size e. A cell placed in a hypotonic solution will remain the same size

b. a cell placed in a hypotonic solution will swell

3. Which of the following proteins requires ATP for its functioning? a. Recognition protein b. Receptor protein c. Active transporter protein d. Passive transporter protein e. Adhesion protein

c. Active transporter protein

13. Which process specifically moves water molecules across a differentially permeable membrane?

Osmosis

14. Which process explains the movement of molecules against a concentration gradient?

Active transport

15. Be able to explain concentration gradient, osmosis, facilitated diffusion, active transport, and diffusion.

concentration gradient: there is a high concentration on one side of a membrane, and a low concentration on the other side. The gradient moves from high to low. osmosis: moves water across differentially permeable membranes facilitated diffusion: process of spontaneous passive transport of molecules or ions across a biological membrane via specific transmembrane integral proteins. active transport: the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy diffusion: the net passive movement of particles from a region in which they are in higher concentration to regions of lower concentration

7. Movement of a molecule against a concentration gradient is a. Simple diffusion b. Facilitated diffusion c. Osmosis d. Active transport e. Bulk flow

d. Active transport

8. The sodium-potassium pump is an example of a. Simple diffusion b. Facilitated diffusion c. Osmosis d. Active transport e. Bulk flow

d. Active transport

6. Which substance passes most readily into a cell? a. Ions b. Large molecules c. Glucose d. Carbon dioxide e. Polar molecules

d. Carbon dioxide

1. The phospholipid molecules of most membranes have a... a. Hydrophobic head and hydrophilic tail b. Hydrophobic head and a hydrophobic tail c. Hydrophobic head and two hydrophobic tails d. Hydrophilic head and two hydrophobic tails e. None of the above

d. Hydrophilic head and two hydrophobic tails

4. A concentration gradient ceases to exist when a. All the molecules have moved from high concentration to low b. The membrane pores close c. The temperature drops d. There is no net movement e. Bulk flow intervenes

d. there is no net movement

11. Wilting of a plant occurs a. if the plant is placed in an isotonic solution b. if there is a rise in turgor pressure c. as a result of facilitated diffusion d. when a plant with flexible cell walls is placed in a hypertonic solution e. all of the above

d. when a plant with flexible cell walls is placed in a hypertonic solution

5. In simple diffusion, the a. Rate of movement of molecules is influenced by temperature and pressure b. Movement of individual molecules is random c. Movement of molecules of one substance is independent of the movement of any other substance d. Net movement is away from the region of highest concentration e. All of the above

e. All of the above

10. If a plant cell is placed in a hypotonic solution, the a. Entire cell will not swell or shrink b. Entire cell will shrink c. Turgor pressure will increase d. Cell wall prevents the cell from exploding e. Turgor pressure will increase, but the cell wall prevents the cell from exploding

e. turgor pressure will increase, but the cell wall prevents the cell from exploding