The interstitial fluid comprises what percentage of the extracellular fluid?
|A)||are the protein fibers of the cytoskeleton|
|B)||are glycoproteins that are found extending through the plasma membrane|
|C)||are enzymes that break down extracellular matrix proteins|
|D)||are proteins that inhibit blood clotting|
If transport through a cell membrane requires the expenditure of energy, it is called ____________.
Movement of water through a cell membrane, rather than a solute, is called _________.
Which of the following substances is least able to diffuse through a living cellular membrane?
Cells continually generate carbon dioxide and must get rid of it. The mechanism by which carbon dioxide moves out of the cell is by ________________.
Ion channels in a cell membrane permit the selective passage of ____________.
|B)||Na+ and K+|
|D)||small organic wastes|
The number of molecules diffusing through a membrane per unit time (rate) depends on all of the following except the ____________.
|A)||concentration of molecules on each side of the membrane|
|B)||availability of ATP|
|C)||permeability of the membrane to the molecules|
|D)||surface area of the membrane|
A high density of microvilli is to be expected especially on the surface of epithelial cells located in the _______________.
Two solutions are said to differ in ________ if they have different concentrations of non-penetrating solutes.
Red blood cells placed in a hypertonic solution will ________________.
|A)||swell and eventually lyse|
When the body gains water and the blood becomes too diluted, it is detected by osmoreceptors located in the ____________.
The primary effect of antidiruetic hormone (ADH) is to _____________.
|A)||lower the osmolality of the blood|
|B)||raise the osmolality of the blood|
|C)||prevent unnecessary loss of water|
|D)||inhibit the sense of thirst|
Cells take in oxygen by simple diffusion and glucose by facilitated diffusion. Therefore, oxygen uptake and glucose uptake will differ from each other in all of the following respects except ________________.
|B)||the need for ATP|
|C)||competition by other solutes|
Extracellular fluid contains up to 10,000 times more calcium than intracellular fluid, and yet all cells continue to pump out even more calcium. They could only do this by means of ______________.
Primary active transport involves a conformational change in the carrier protein. The most immediate stimulus for this is ______________.
|A)||a change in membrane voltage|
|B)||binding of the carrier protein to a molecule in the extracellular fluid|
|C)||phosphorylation (binding of the carrier protein to a phosphate group) within the cell|
|D)||fluctuations in the pH of the medium around the carrier protein|
Living cells are negatively charged inside primarily because of ___________.
|A)||ATP, organic acids, and other negative molecules that cannot escape|
|B)||Removal of sodium ions, which are positively charged, by the Na+/K+ pump|
|C)||Extrusion of Ca2+ ion, which is much more concentrated outside a cell than inside|
|D)||Cell membranes that are more permeable to potassium than sodium|
The cell membrane is more permeable to _______ than any other cation.
The membrane of a resting cell leaks sodium and potassium ions, but the ________ compensates for this and maintains the membrane potential near a constant value.
|B)||transport of calcium ions|
|C)||closure of potassium channels in the membrane|
|D)||closure of sodium channels in the membrane|
Facilitated diffusion can transport molecules against a concentration gradient.
Simple diffusion does not require a living cell membrane.
The spontaneous, random diffusion of molecules creates a concentration gradient.
A concentration gradient is a state of low entropy.
The dialysis membranes used in the treatment of kidney disease do not allow plasma protein molecules to pass.
The basal lamina consists of collagen and is part of the extracellular matrix.