Membranes and Transport Quiz
1. Biological membranes
ARE COMPOSED OF PHOSPHOLIPIDS, ARE ASYMMETRIC, CONTAIN PROTEINS, AND CONTAIN DISCRETE COMPONENTS THAT CAN MOVE WITHIN THE BILAYER
2. Which of the following statements about the proteins of the plasma membrane and the inner mitochondrial membrane is true?
THE FUNCTION OF EACH MEMBRANE DETERMINES WHICH PROTEINS ARE PRESENT
3. The energy for ____ transport of a molecule across a membrane comes directly from its concentration gradient.
4. The most common motif found in membrane-spanning proteins is:
ALPHA HELICES OF NONPOLAR AMINO ACIDS THAT PASS THROUGH THE MEMBRANE
5. The low incidence of protein or lipid flip-flop in a membrane preserves:
6. Membrane fragments from different areas of a cell are constantly breaking down, moving, and in some cases fusing with other parts of a membrane. This is possible because of
THE ABILITY OF LIPIDS TO ASSOCIATE WITH ONE ANOTHER AND SEAL THEMSELVES
7. In an experiment you have two identical solutions of glucose, called A and B, that are separated in a dish by a membrane that will allow the movement of particles and water. You want to establish a concentration gradient so that the glucose in B will move across into A. How could you manipulate your experimental setup so that the glucose will move in that direction?
ADD MORE WATER TO COMPARTMENT A
8. Which of the following statements about channel proteins is true?
THEY HAVE A CENTRAL PORE OF POLAR AMINO ACIDS AND WATER, THEY ARE ANCHORED IN THE HYDROPHOBIC BILAYER OF THE PLASMA MEMBRANE, THEY ARE SURROUNDED BY NONPOLAR AMINO ACIDS, AND THEY ARE USUALLY GATED
9. Look at Sadava Figure 6.15. In this model illustrating secondary active transport, transport of glucose against its concentration gradient is directly driven by
A SODIUM GRADIENT