Which of the following types of molecules are the major structural components of the cell membrane?
phospholipids and proteins
Which of the following is a function of the cell membrane?
regulates which materials enter and leave the cell
The cell membrane contains channels and pumps that help move materials from one side to the other. What are these channels and pumps made of?
Why can the cell membrane of a cell be described as selectively permeable?
It restricts the passage of some solutes
Cholesterol is repelled by water and can be found between the layers of the phospholipids in the plasma membrane. What can be concluded from this information?
Cholesterol is non-polar
Which protein in the plasma membrane helps identify chemical signals from outside the cell?
When the pancreas releases glucagon to the liver it is becasue there is
high levels of sugar in the blood
The ability of the body's immune system to distinquish between its own cells and an invading bacterium depends upon
the carbohydrate tag
Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?
At what point in the process of diffusion is dynamic equilibrium reached?
When there is continuous movement but no change
Which term describes the relatively constant internal physical conditions of an organism?
A single-celled organism lives in salt water is placed in a fresh water pond. Which of there would most likely occur to that organism?
it would sweet, eventually bursting
A cell which lives at 10% salt water, was moved into another solution.Which of these solutions would cause the cell to increase size at the greatest rate?
Spartina, a cord grass, grows in salt marshes and stores salt in its roots. This makes the salt concentration in its roots greater than that of the surrounding water. What most likely occurs in repsonse to this slat concentration in the roots?
water moves into the roots
Algal cells are placed in an isotonic solution. Additional amounts of solutes are slowly added to the solution. What happens to the cells?
It will shrink
A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water, equal to the volume of blood lost, is transferred directly into one of his veins. What will be the most probable result of this transfusion?
The patients cells will burst
Refer to the illustration above. Which cell is most likely to lose both water molecules and solute molecules as the system approaches equilibrium?
Refer to the illustration above. In this system, solute molecules in cell "B" are most likely to
DIffuse into a's cells