Chapter 5: Life’s Border: The Plasma Membrane

1.	Which of the following statements concerning membrane proteins is incorrect? (level 1). [Hint]
2.	Refer to the illustration. Which molecule represents a glycoprotein that may function as a cellular ID tag, allowing cells of the immune system to recognize a cell as native to the body? (level 2). [Hint]
3.	Refer to the illustration. Which molecule may function in facilitated diffusion? (level 2) [Hint]
4.	Refer to the illustration. Which molecule is a polysaccharide attached to a phospholipid? (level 1). [Hint]
5.	Refer to the illustration. Which molecule might serve as a binding site for a hormone, thereby eliciting a response in the cell? (level 2). [Hint]
6.	Refer to the illustration. Which molecule works to keep the membrane at optimal fluidity? (level 2). [Hint]
7.	Refer to the illustration. Which molecule is both hydrophobic and hydrophilic and aggregates as a bilayer to form the "fabric" of the membrane? (level 1). [Hint]
8.	What is the significance of selective permeability to biological membranes? (level 2). [Hint]
9.	The movement of molecules across a membrane against their concentration gradient, at the expense of ATP energy, is called ... (level 1) [Hint]
10.	Just as with most liquids, the fluid lipid bilayer can solidify and freeze at very cold temperatures. However, there are certain kinds of fish that live in very cold water. The cell membranes of these fish are likely to have more of which of the following membrane components than would a fish that occupies warmer waters? (level 2). [Hint]
11.	The activity of the sodium/potassium pump is critically important in maintaining proper ion concentrations across the cell membrane. Which of these steps is necessary in the pumping activity of this protein? (level 2). [Hint]
12.	Which of the following types of transport does NOT require the use of a transport protein? (level 1). [Hint]
13.	What do you think would happen to an animal cell that was placed into a drop of 100% pure water? (level 2) [Hint]
14.	In the process of diffusion ... (level 1). [Hint]
15.	Materials that are too large to move out of the cell through either the lipid bilayer or a transport protein must be moved out through the process of ...(level 1). [Hint]
16.	Large food particles, or perhaps whole organisms, can be engulfed and pulled into the cell by the process of ... (level 1). [Hint]
17.	Many of the proteins that are associated with the cell membrane are said to be "integral" proteins. An integral protein is defined as a protein that is ... (level 1). [Hint]
18.	Of the four primary functions of membrane proteins, which one does NOT require that the protein be in contact with the extracellular fluid? (level 1). [Hint]
19.	Which of the following molecules or ions would normally need to use a membrane protein in order to move through the cell membrane? (level 2). [Hint]
20.	Which of the following processes uses a difference in concentration (or concentration gradient) to transport molecules across the cell membrane? (level 2) [Hint]
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