Which of the following statements about a typical plasma membrane is correct?
- The plasma membrane is a covalently linked network of phospholipids and proteins that controls the movement of solutes into and out of a cell.
- The two sides of the plasma membrane have different lipid and protein composition.
- The hydrophilic interior of the membrane is composed primarily of the fatty acid tails of the phospholipids.
- Carbohydrates on the membrane surface are important in determining the overall bilayer structure.
The two sides of the plasma membrane have different lipid and protein composition.
The permeability of a biological membrane to a specific polar solute depends primarily on which of the following?
- the phospholipid composition of the membrane
- the presence of unsaturated fatty acids in the membrane
- the types of polysaccharides present in the membrane
- the types of transport proteins in the membrane
the types of transport proteins in the membrane
The presence of aquaporins (proteins that form water channels in the membrane) should speed up the process of osmosis.
- True
- False
True
In facilitated diffusion, transport proteins provide a hydrophobic route for the solute to cross the membrane.
- True
- False
False
Ex.
Actually should be, "In facilitated diffusion, transport proteins provide a hydrophillic route for the solute to cross the membrane."
The movement of glucose into a cell against a concentration gradient is most likely to be accomplished by which of the following?
- facilitated diffusion of the glucose using a carrier protein
- passive diffusion of the glucose through the lipid bilayer
- cotransport of the glucose with a proton or sodium ion that was pumped across the membrane using the energy of ATP hydrolysis
- movement of glucose into the cell through receptor-mediated endocytosis
cotransport of the glucose with a proton or sodium ion that was pumped across the membrane using the energy of ATP hydrolysis