QUIZ - Ch. 5, 6
Name _______________________________
Biology 121 - 9/19/08
__B_ 1. Osmosis:
a. is the active transport of water against its concentration gradient.
b. is the passive transport of water down its concentration gradient.
c. is the passive movement of any particle down its concentration gradient.
d. None of the above are correct.
__C_ 2. Which of the following is not true of the plasma membrane?
a. It has a "fluid mosaic" structure.
b. The phospholipid bilayer has a hydrophobic interior.
c. Water-soluble molecules can pass freely between the phospholipids in the bilayer.
d. Proteins within the membrane can provide a cell "identity".
__B_ 3. Integral/transmembrane membrane proteins:
a. are held in place by phosphotidylinositol.
b. may provide channels for the transport of molecules or ions across the membrane.
c. are easily removed from the membrane.
d. are often attached to only the inner or outer surface of the cell membrane.
__A_ 4. The description of a membrane as “fluid mosaic” means:
a. membranes are made of proteins and lipids that can freely move.
b. the phospholipids that make up the membrane can move.
c. the membrane is a mosaic of phospholipids and proteins.
d. water molecules make up part of the membrane.
__A_ 5. During an oxidation-reduction (redox) reaction, the molecule that gains an electron has been:
a. reduced.
b. oxidized.
c. rendered useless.
d. given a positive charge.
__B_ 6. The energy stored in an ATP molecule is found:
a. within the bonds between nitrogen and carbon.
b. in the bonds connecting the two outermost phosphate groups.
c. in the oxygen double bond.
d. in the carbon bonds found in the ribose.
__A_ 7. The active site of an enzyme:
a. binds the substrate molecules that are acted upon in the reaction.
b. binds noncompetitive inhibitor molecules.
c. binds activator molecules.
d. is composed of nucleic acids.
8.
Enzymes catalyze reactions by lowering the ____activation energy_______________ of the reaction.
9.
A red blood cell is placed in a fluid that causes a net movement of water out of the cell. The
fluid is best described as being _________hypertonic__________________.
10. In the Na+/K+ pump, ________3_________ Na+ are moved out of the cell, ______2_____ K+ are
moved into the cell, and one ATP is used to fuel the process.