Which type of membrane junction is an example of a tight junction?
Junctions among epithelial cells lining the digestive tract.
Which of the following is a difference between primary and secondary active transport:
In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated.
Which of the following forms of vesicular transport processes are used by flu viruses, diphtheria, and cholera toxins to enter our cells?
Which of the following processes allows cells to concentrate material that is present only in very small amounts in the extracellular fluid?
Your patient has the flu and reports 5 to 6 loose stools a day. He has experienced an isotonic fluid volume loss. What does "isotonic fluid loss" mean?
Water and electrolytes are lost in equal proportions.
Which of the following is true regarding the membrane potential?
Both potassium and sodium ions can "leak" through the cell membrane due to diffusion.
In the maintenance of the cell resting membrane potential ________.
extracellular sodium levels are high
In osmosis, movement of water occurs toward the solution with the lower solute concentration.
The most common extracellular ion is ________.
Which cell component helps to maintain the structural integrity of the cell?
All epithelia have an apical surface and a basal surface.
Which type of membrane is also an organ system?
Which of the following is true regarding the concentration of solutions?
Molarity is one mole of solute per 1000 ml of solution.
Which of the following factors act to bind cells together?
Specialized junctions, wavy membrane contours, and glycoproteins
Cell junctions that promote the coordinated activity of cells by physically binding them together into a cell community include all of the following except ________.
A ________ is a channel between cells.
Which of the following is not a factor that binds cells together?
glycolipids in the glycocalyx
A red blood cell placed in pure water would ________.
swell and burst
If cells are placed in a hypertonic solution containing a solute to which the membrane is impermeable, what could happen?
The cells will lose water and shrink.
Passive membrane transport processes include ________.
movement of a substance down its concentration gradient
Your patient has a respiratory disease that has literally paralyzed the cilia. Why would this patient be at an increased risk for a respiratory infection?
If cilia are paralyzed then mucus-containing particles, including bacteria, will remain in the lungs and may cause a respiratory infection.
Ribosomes, endoplasmic reticulum, and the Golgi apparatus functionally act in sequence to synthesize and modify proteins for secretory use (export) only, never for use by the cell. This statement is ________.
false; integral cell membrane proteins are also synthesized this way
Which of the following best describes why cells need active transport mechanisms?
to move solutes against their concentration gradients
What sort of Ca2+ concentrations are maintained by the calcium pump?
The Ca2+ concentration is higher in the extracellular fluid than in the cytoplasm.
Most cancer cells have a lower intracellular ATP concentration compared to normal cells. How would you expect this to affect the Na+-K+ pump in cancer cells?
The Na+-K+ pump would work slower.
What is the energy source used by the Na+-K+ pump during its normal operation?
hydrolysis of ATP
Which of the following best describes how phosphorylation affects the Na+-K+ pump?
Phosphorylation causes the pump to change shape.
What triggers the release of phosphate from the Na+-K+ pump?
binding of K+ ions to the pump
What event initiates ATP attachment to the Na+-K+ pump, leading to the pump's phosphorylation?
the binding of Na+ ions to the pump
What sort of ion distributions are established and maintained by Na+-K+ pump activity?
high Na+ concentration in the extracellular fluid; high K+ concentration in the cytoplasm