Specificity is an important characteristic of intercellular communication; which of these best explains how it occurs?
A. The phospholipid composition of the plasma membrane differs among cells.
B. Protein receptors are only located on the surface of target cells.
C. All cells have the same DNA, so any cell can express protein receptors for a specific chemical.
D. Chemical messengers are all proteins, so bind only to receptors that are proteins.
E. Protein receptors for chemical messengers are only expressed in specific target cells.
(
Question 2) What are the most common receptors for hydrophilic intercellular messenger molecules?
A. peripheral membrane proteins
B. integral membrane proteins
C. specialized phospholipids within the membrane
D. nucleic acids
E. intracellular proteins
(
Question 3) The plasma membranes of epithelial cells facing the lumen of hollow organs or tubes have the same transport proteins as the plasma membranes that face the interstitial fluid.
Indicate whether the statement is true or false.
(
Question 4) Most organic solutes cross epithelial membranes by simple diffusion on the lumen side followed by active transport across the blood side of the membrane.
Indicate whether the statement is true or false.
(
Question 5) Net movement of solute across an epithelium that is permeable to water is always accompanied by movement of water in the opposite direction.
Indicate whether the statement is true or false.
(
Question 6) The luminal side of an epithelial cell is also known as the basolateral side.
Indicate whether the statement is true or false.
(
Question 7) The clathrin protein involved in carrying out receptor-mediated transport remains with an endosome as it moves deep within the cell and is degraded entirely along with the ingested internal contents.
Indicate whether the statement is true or false.
(
Question 8) Phagocytic leukocytes use phagocytosis to engulf foreign bacteria and destroy them within ribosomes.
Indicate whether the statement is true or false.
(
Question 9) Pinocytosis is a method by which molecules can leave cells whose membranes are impermeable to the molecules.
Indicate whether the statement is true or false.
(
Question 10) Endocytosis of any kind requires metabolic energy.
Indicate whether the statement is true or false.
Quick Reply
