Reading Guided - Cells and the Extracellular Environment I 1. Which of the following is a function of the steep Na+/K+ gradient across the cell membrane? A. provides energy for coupled transport B. creates electrochemical impulses C. maintains osmotic pressure D. All of these choices are correct. 2. Ions like Ca2+ can be second messengers for cell signaling. True False 3. Hypertonic solutions stimulate cellular lysis. True False 4. In secondary active transport, if the other substance is moved in the same direction as Na+, it is called A. cotransport. B. symport. C. antiport. D. Both cotransport and symport are correct. 5. ___________ g of sucrose (molecular weight = 342g) would be added to 1L of water to produce a 2.5 Osm solution. A. 342 B. 500 C. 855 D. 2.5 6. The Na+/K+ pump creates a ____________ charge inside the cell. A. positive B. negative 7. Which of the following is NOT true of cyclic AMP? A. It is found on the outside of a plasma membrane. B. It is a second messenger for polar regulatory molecules. C. It is made from ATP. D. It activates enzymes inside a cell to produce the desired effect. 8. Epithelial cells have a polarity dealing with transport. True False 9. 80% of the extracellular fluid is termed interstitial fluid. True False 10. How much of the extracellular fluid makes up the blood plasma? A. 33% B. 92% C. 20% D. 50%
11. Why are cells in body organs generally within 100 m of a blood capillary? A. to decrease mean diffusion time B. to increase mean diffusion time C. so that larger particles can diffuse more easily D. a larger distance maximizes entropy 12. How much of the total body water content is in the intracellular compartment? A. 50% B. 67% C. 33% D. 80% 13. A cell placed in a 9% saline solution (molecular weight = 58.5g) would A. lyse. B. crenate. C. not change. D. swell. 14. Secondary active transport often occurs as a coupled transport process. True False 15. Facilitated diffusion is unable to transport molecules against a concentration gradient. True False 16. Inhibition of receptor-mediated endocytosis A. could induce hypercholesteremia. B. could induce diabetes mellitus. C. could prevent diabetes mellitus. D. could prevent heart disease. 17. The osmotic pressure exerted by a cell would decrease if the cell synthesized more proteins. True False 18. Active transport proteins are often regulated by phosphorylation. True False 19. What type of functional complex will prohibit paracellular transport? A. tight junctions B. adherens junctions C. desmosomes D. gap junctions 20. A solution freezing at -1.98 C A. is hypotonic to plasma. B. is isotonic to plasma. C. is hypertonic to plasma. D. is not related to plasma.
21. Protein carrier mediated transport of molecules display A. specificity. B. competition. C. saturation. D. All of these choices are correct. 22. Gas exchange between the cells and extracellular fluid utilizes active transport. True False 23. Channels present in the membranes of some cells that allow rapid movement of water are called A. water tubes. B. aqueducts. C. aquaporins. D. streams. 24. What structures are used for direct cell to cell signaling? A. desmosomes B. tight junctions C. exocytosis vesicles D. gap junctions 25. What type of cell signaling occurs through the extracellular matrix to nearby target cells? A. endocrine signaling B. synaptic signaling C. gap junctions D. paracrine signaling
Guided Reading - Cells and the Extracellular Environment II 1. Edema will result if a person has an abnormally low concentration of plasma proteins. True False 2. Osmoreceptors are involved in the regulation of blood volume. True False
3. Ion channels that can be opened by physiological stimuli are said to be A. polar. B. aquaporins. C. hypertonic. D. gated. 4. The calcium pump is also an ATPase enzyme. True False 5. Where is the receptor for a nonpolar, lipid-soluble regulatory molecule? A. embedded in the outer surface of the plasma membrane B. embedded in the inner surface of the plasma membrane C. in the cytoplasm or nucleus of the cell D. All of the choices are correct. 6. Diffusion is more rapid in cells with microvilli compared to cells lacking microvilli. True False 7. Which of the following is true of oral rehydration therapy? A. It is used to treat severe diarrhea. B. The presence of glucose aids the intestinal absorption of Na+ and water. C. It saves more than a million small children per year. D. All of these choices are correct. 8. ________ are a class of glycoproteins that bind to components in the extracellular matrix thereby acting as adhesion molecules between cells and the matrix. A. Glycocalyces B. Aquaporins C. Desmosomes D. Integrins 9. Active transport A. utilizes energy. B. cannot transport molecules against a concentration gradient. C. cannot be saturated. D. requires cofactors. 10. Osmotic pressure is a measure of the force needed to A. open aquaporins. B. cause osmosis. C. stop osmosis. D. stop edema. 11. Simple diffusion is the net diffusion of a solvent. True False
12. The osmotic pressure of a solution is directly related to its ___________ concentration. A. water B. solute C. solvent D. matrix 13. Where is the G-protein complex when a regulatory molecule is not bound to its receptor? A. The alpha subunit is attached to the inner surface of the receptor. B. The three subunits are together but not attached to the inner surface of the receptor. C. The three subunits are together AND attached to the inner surface of the receptor. D. The beta and gamma subunits are attached to the inner surface of the receptor. 14. Individuals suffering from cystic fibrosis have defective ____________ ion channels. A. sodium B. potassium C. calcium D. chloride 15. ____________ transport does not require membrane proteins. A. Facilitated diffusion B. Bulk C. Simple diffusion D. Active 16. Hydrophobic molecules usually enter a cell via __________. A. osmosis B. active transport C. diffusion D. protein channels 17. Where are GLUT carriers located in an unstimulated muscle? A. in the plasma membrane facing the external environment B. in the plasma membrane facing the internal environment C. within cytoplasmic vesicles D. There are no GLUT carriers present. 18. A one molar solution would contain 6.02 1023 molecules of solute. True False 19. A 0.5M glucose (molecular weight = 180g) contains ____________ grams of glucose per liter. A. 90 B. 180 C. 6.02 1023 D. 360 20. Which of the following cells do NOT normally have many aquaporins in their plasma membranes? A. kidneys B. lungs C. salivary glands D. skin
21. How do small ions like Na+ of K+ pass through the plasma membrane? A. gated channels B. ion channels C. carrier proteins D. simple diffusion 22. Poisoning the Na+/K+ pump would cause the volume of the cell to __________. A. increase B. decrease C. remain the same 23. Active transport proceeds when energy is expended. True False 24. Poisoning the Na+/K+ pump would A. generate a more negative membrane potential. B. increase cellular permeability to Na+. C. inhibit secondary active transport. D. increase cellular permeability to K+. 25. What molecules pass information from the polar regulatory molecule receptor to activate the enzymes that produce cAMP? A. paracrines B. G-proteins C. GTP D. None of these choices are correct.
Guided Reading Cells and the Extracellular Environment III 1. The resting membrane potential closest is to the equilibrium potential for A. sodium ions. B. chloride ions. C. calcium ions. D. potassium ions. 2. The transport maximum is related to the property known as A. competition. B. saturation. C. specificity. D. inhibition. 3. Glucose transported via the GLUT carrier is characterized as A. active transport. B. passive transport. C. co-transport. D. receptor-mediated endocytosis. 4. A six molar sucrose (molecular weight = 342g) solution would contain A. 57g sucrose per liter. B. 342g sucrose per liter. C. 1026g sucrose per liter. D. 2052g sucrose per liter. 5. Plasma freezes at A. -1.86C. B. -1.00C. C. -0.56C. D. 0.00C. 6. Solutes that cannot freely pass through a membrane are said to be A. hypertonic. B. osmotically inactive. C. osmotically active. D. selectively permeable. 7. Osmosis and simple diffusion do NOT require the actions of carrier proteins. True False 8. One mole of solute per liter depresses the freezing point of water by -1.86 C. True False 9. A solution consists of a ____________ which dissolves the ____________. A. solvent, solute B. solvent, solid C. solute, solvent D. liquid, solid
10. Transport of materials through an epithelial cell is called A. paracellular transport. B. transcellular transport. C. bulk transport. D. exocytosis. 11. The transport of molecules out of the urinary filtrate and into the blood is called A. absorption. B. reabsorption. C. countertransport. D. symport. 12. What structures affect cell motility, adhesion, and proliferation? A. basal lamina B. integrins C. collagen IV D. proteoglycans 13. The charge difference across a membrane produces the membrane potential. True False 14. The process in which waste molecules are removed from the blood by having them diffuse through an artificial porous membrane is called dialysis. True False 15. What type of cell signaling uses chemicals called neurotransmitters to innervate its target organ? A. synaptic signaling B. paracrine signaling C. endocrine signaling D. gap junctions 16. Most cells have a resting membrane potential between A. +60mV and -90mV. B. -60mV and -90mV. C. -65mV and -85mV. D. +65mV and +90mV. 17. Cells placed in hypotonic solutions will A. decrease in volume. B. increase intracellular solute concentration. C. increase in volume. D. lose water to the solution. 18. Which regulatory molecule cannot enter its target cell? A. epinephrine B. acetylcholine C. nitric oxide D. Both epinephrine and acetylcholine are correct.
19. ___________________ comprise an important family of enzymes that can break down extracellular matrix proteins but require a zinc ion cofactor. A. Matrix metallohydrolases B. Matrix phosphokinases C. Matrix metalloproteinases D. None of these choices are correct. 20. The glucose carrier of skeletal muscle is designated as A. GLUT2. B. GLUTSk. C. GLUT4. D. GLUT5. 21. A one molal NaCl solution has the same osmolality as a one molal glucose solution. True False 22. Secondary active transport A. utilizes energy directly. B. often utilizes symport proteins. C. always uses the influx of sodium ions. D. is only important in the kidney. 23. A 0.1 Osm plasma sample would A. stimulate the action of osmoreceptors. B. be hypertonic to the cells. C. stimulate an increase in blood volume. D. inhibit the release of antidiuretic hormone. 24. Active transport carriers are also called A. vesicles. B. channels. C. pumps. D. receptors. 25. Which of the following is able to passively penetrate the plasma membrane? A. O2 B. small charged particles C. large polar molecules D. All of these choices are correct.
Guided Reading - Cells and the Extracellular Environment IV
1. Which of the following is NOT a primary active transport pump? A. GLUT4 B. calcium pump C. sodium/potassium pump D. proton pump 2. What cofactor do matrix metalloproteinases need to be functional? A. calcium B. copper C. chromium D. zinc 3. Bulk transport is required for the transport of large polar molecules into or out of cells. True False 4. The Na+/K+ pump transports _______ into the cell and ________ out of the cell per cycle. A. 3Na+, 2K+ B. 2Na+, 3K+ C. 3K+, 2Na+ D. 2K+, 3Na+ 5. Which of the following is NOT a function of integrins? A. glue components of the matrix B. communicate between the intracellular and extracellular compartments C. allow diffusion to occur through the plasma membrane D. establish cell polarity 6. The rate of diffusion increases as the concentration gradient increases. True False 7. Which G-protein subunit binds GDP? A. alpha subunit B. beta subunit C. gamma subunit D. delta subunit 8. Passive transport of water is known as A. filtration. B. osmosis. C. facilitated diffusion. D. a water pump. 9. The osmolality of plasma is A. 0.3 Osm. B. 0.1 Osm. C. 1.0 Osm. D. 2.0 Osm.
10. Diffusion ____________ the entropy of a solution. A. decreases B. increases C. does not change 11. Which of the following is NOT a G-protein? A. alpha B. beta C. delta D. gamma 12. If the intracellular concentration of Ca2+ was 10mEq/L and the extracellular concentration was 150mEq/L, the Ca2+ equilibrium potential would be A. -35.9mV. B. -71.8mV. C. +35.9mV. D. +71.8mV. 13. Hyperkalemia would ____________ the resting membrane potential of the cell. A. increase B. decrease C. have no effect on 14. ____________________ is a term which describes a membrane that allows only certain molecules to penetrate it. A. Selectively permeable B. Permeable C. Porous D. Countertransport 15. Glucose entry into the cell is by facilitated diffusion. True False 16. Facilitated diffusion of a molecule into a cell would be more rapid if A. the concentration of the molecule in the cell increased. B. the concentration of water in the cell decreased. C. the concentration of the molecule outside the cell increased. D. the cell was isotonic. 17. Which of the following is NOT true of hypoglycemia? A. It can result in death. B. It may be due to diabetes. C. It is characterized by high plasma glucose levels. D. Both it can result in death and it may be due to diabetes are correct. 18. The rate of diffusion is influenced by A. the concentration gradient. B. membrane permeability. C. membrane surface area. D. All of these choices are correct.
19. Matrix metalloproteinases A. produce the basal lamina. B. synthesize collagen in the extracellular matrix. C. may be active in invasive cancer cells. D. synthesize proteoglycans in the extracellular matrix. 20. Dialysis uses the process of A. facilitated diffusion. B. primary active transport. C. simple diffusion. D. secondary active transport. 21. Desmosomes are a type of junctional complex. True False 22. Which of the following is NOT true of a person who is dehydrated? A. plasma osmolality increases B. hypothalamus stimulates release of ADH C. ADH causes the kidneys to excrete water D. increased osmolality causes thirst 23. The majority of water within the body is found in the A. intracellular compartment. B. extracellular compartment. C. blood plasma. D. interstitial fluid. 24. The Na+/K+ pump A. establishes equilibrium concentrations of sodium and potassium ions. B. is an electrogenic pump. C. is an example of secondary active transport. D. interferes with glucose transport. 25. What is necessary for a target cell to respond to a cell signaling molecule? A. being close together B. a second messenger C. specific receptor proteins D. All of these choices are necessary.