What aspect of the membrane prevents water soluble substances from crossing the membrane?
a. membrane phospholipids.
b. how much cholesterol is present.
c. the number and types of membrane proteins.
d. the charge of the membrane.
e. none of these answers.
A
You might also like to view...
The concentrations of two substances are increasing outside the cell. For substance A, transport into the cell increases proportionally as the concentration outside increases. For substance B transport into the cell increases but then levels off despite the concentration outside continuing to increase. What is the explanation for this?
A. Saturation B. Affinity C. Competition D. Specificity
Sylvia is suffering from severe edema (an abnormal buildup of serous fluid between tissue cells) in her arms and legs. Her physician prescribes a diuretic (a substance that will increase the volume of urine produced). Why might this help to alleviate Sylvia's problem?
What will be an ideal response?
If a blood buffer is absent, which function of the blood would be compromised?
A. Transport of ions B. Clot formation C. Regulation of pH D. Protection against foreign substances E. Maintenance of body temperature
During vagal stimulation of the frog heart, you observe which of the following?
A) The heart slows until it almost stops, then speeds up. B) The heart stops beating, and the frog dies. C) The heart slows, stops, and then begins to beat again. D) The heart slows down.