Biology Chapter 7 Questions
Lysosomes
A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in
a transmembrane protein.
A protein that spans the phospholipid bilayer one or more times is
Phagocytosis
An organism with a cell wall would most likely be unable to take in materials through
amphipathic, with at least one hydrophobic region.
In order for a protein to be an integral membrane protein it would have to be
down their electrochemical gradients
Ions diffuse across membranes through specific ion channels
membranes consist of protein molecules embedded in a fluid bilayer of phospholipids.
Singer and Nicolson's fluid mosaic model of the membrane proposed that
high cellular concentrations of potassium
The movement of potassium into an animal cell requires
Cotransport
The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient across the membrane-more acidic outside the cell than inside the cell. Phosphate transport is an example of
contributes to the membrane potential
The sodium-potassium pump is called an electrogenic pump because it
it moves through aquaporins in the membrane.
Water passes quickly through cell membranes because
membrane potential
What is the voltage across a membrane called?
small and hydrophobic
What kinds of molecules pass through a cell membrane most easily?
It exhibits a specificity for a particular type of molecule.
Which of the following is a characteristic feature of a carrier protein in a plasma membrane?
They are usually transmembrane proteins.
Which of the following is true of integral membrane proteins?
All components of membranes evolve in response to natural selection
Which of the following is true of the evolution of cell membranes?
Na+ ions moving out of a mammalian cell bathed in physiological saline
Which of the following membrane activities require energy from ATP hydrolysis?
It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.
Which of the following statements is correct about diffusion?
phospholipids and proteins
Which of the following types of molecules are the major structural components of the cell membrane?
CO2
Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?
E. Gorter and F. Grendel
Who was/were the first to propose that cell membranes are phospholipid bilayers?