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1 | |
Movement of solutes through a membrane with the use of a transport protein is called (p. 127) |
| | A) | osmosis |
| | B) | facilitated diffusion |
| | C) | carrier-mediated transport |
| | D) | active transport |
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2 | |
If transport through a cell membrane requires the expenditure of energy, it is called (p.127) |
| | A) | facilitated diffusion |
| | B) | active transport |
| | C) | simple diffusion |
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3 | |
Transport of water through a cell membrane, rather than solute, is called (p. 127) |
| | A) | simple diffusion |
| | B) | solvent diffusion |
| | C) | osmosis |
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4 | |
Urea will move freely through a non-living dialysis membrane. Its method of moving through the membrane must therefore be (p. 127) |
| | A) | simple diffusion |
| | B) | facilitated diffusion |
| | C) | active transport |
| | D) | osmosis |
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5 | |
If a membrane that is permeable to urea has a solution of 100 mOsm urea on side A and 300 mOsm urea on side B, (p. 128) |
| | A) | no urea can diffuse from side A to side B |
| | B) | urea will diffuse through the membrane until both sides have 200 mOsm |
| | C) | there will be net diffusion of urea from side A to side B |
| | D) | movement (diffusion) of urea through the membrane will stop when equilibrium is reached |
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6 | |
Which of the following substances is least able to diffuse through a phospholipid cell membrane? (p. 128) |
| | A) | glucose |
| | B) | carbon dioxide |
| | C) | cholesterol |
| | D) | water |
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7 | |
Oxygen has a much lower concentration within a cell than in the extracellular fluid because(p. 128) |
| | A) | oxygen is unable to pass through cell membranes |
| | B) | carrier molecules continually remove oxygen from cells |
| | C) | as soon as oxygen enters a mitochondrion of the cell it is converted to water |
| | D) | oxygen is continually supplied to the extracellular fluid by the blood |
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8 | |
Cells continually generate CO2 and must get rid of it. The mechanisms for getting CO2 out of the cell is (p. 128) |
| | A) | active transport |
| | B) | facilitated diffusion |
| | C) | cotransport |
| | D) | simple diffusion |
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9 | |
Ion channels in a cell membrane permit the selective passage of (p. 129) |
| | A) | respiratory gases |
| | B) | Na+ and K+ |
| | C) | amino acids |
| | D) | small organic wastes |
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10 | |
The number of molecules diffusing through a membrane per unit time (rate) depends on all of the following except the (p.129) |
| | 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 |
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11 | |
Sudden changes in the permeability of a membrane to a certain solute are achieved by (p. 129) |
| | A) | increasing the concentration gradient of the solute |
| | B) | increasing the number of carrier proteins in the membrane |
| | C) | increasing the transport maximum of the membrane |
| | D) | changes in the shape of carrier proteins in the membrane |
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12 | |
A high density of microvilli is to be expected especially on the surface of epithelial cells located in the (p. 129) |
| | A) | brain |
| | B) | liver |
| | C) | muscles |
| | D) | small intestine |
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13 | |
Solutes that cannot pass through a semipermeable membrane are said to be (p. 130) |
| | A) | osmotically active |
| | B) | osmotically inert |
| | C) | isotonic |
| | D) | isosmotic |
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14 | |
Water passes from the tissue fluids into the blood capillaries mainly because the (p. 131) |
| | A) | blood has a lower protein concentration than the tissue fluids |
| | B) | blood has a higher protein concentration than the tissue fluids |
| | C) | blood contains more salt than the tissue fluids |
| | D) | tissue fluids are more concentrated than the blood plasma |
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15 | |
A deficiency of protein in the blood caused by liver disease such as cirrhosis, where the damaged liver is unable to produce adequate amounts of the protein albumin, leads to (p. 131) |
| | A) | edema |
| | B) | high blood volume |
| | C) | high blood pressure |
| | D) | ADH secretion |
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16 | |
Plant cells have a tough, fibrous cell wall that can push against the expanding cell membrane and prevent the uptake of excess water. The pressure that the cell wall must generate to oppose the uptake of water is called (p. 131) |
| | A) | osmotic pressure |
| | B) | hydrostatic pressure |
| | C) | osmolality |
| | D) | tonicity |
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17 | |
The atomic weights of the following elements are C=12, O=16, H=1. The formula for glucose is C6H12O6. Maltose is made by combining two glucose molecules, with the removal of -H and -OH groups to form water as a by-product. Thus the molecular weight (MW) of maltose is (p. 131) |
| | A) | 58 |
| | B) | 180 |
| | C) | 342 |
| | D) | 360 |
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18 | |
Avogadro's number (6.02 x 1023) refers to (p. 131) |
| | A) | how many moles of solute are needed to make an isotonic solution |
| | B) | the freezing point depression in relation to osmolality |
| | C) | how many molecules are present in one mole of a substance |
| | D) | how many moles of a substance are present on one kilogram |
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19 | |
The atomic weights of the following elements are C=12, N=14, O=16, and H=1. The formula for glutamic acid (an amino acid) is C5H9O4N. If you wanted to have Avogadro's number of glutamic acid molecules in a beaker, you would weigh out (p. 131) |
| | A) | 6.02 grams of it |
| | B) | 147 grams of it |
| | C) | 45 grams of it |
| | D) | 6.02 x 1023 grams of it |
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20 | |
Glutamic acid weighs 147 grams per mole. To make a 1 M solution of glutamic acid, you could (p. 131) |
| | A) | dissolve 147 g in 1 kg (kilogram) of water |
| | B) | dissolve 147 g in 1 L (liter) of water |
| | C) | dissolve 147 g in enough water to make 1 L of solution |
| | D) | dissolve 147 g in enough water to make 1 kg of solution |
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21 | |
The distinction between a 1.0 M and 1.0 m solution of fructose is the (p. 132) |
| | A) | 1.0 m solution is isotonic and the 1.0 M solution is hypertonic |
| | B) | 1.0 m solution is only one-tenth as concentrated as the 1.0 M solution |
| | C) | 1.0 m solution is only 1/1,000th as concentrated as the 1.0 M solution |
| | D) | 1.0 m solution has more water than the 1.0 M solution |
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22 | |
In biological applications, it is often preferable to measure solution concentrations in molality rather than molarity, especially if comparing solutions of two different substances. This is because (p. 131) |
| | A) | with molarity it is impossible to calculate whether a solution is isotonic to living tissues |
| | B) | two solutions of the same molality have equivalent ratios of solute to water, but two solutions of the same molarity may not have equivalent ratios |
| | C) | if one scientist reports concentrations measured in molality, another scientist elsewhere can exactly replicate the work. This is not possible with molarity |
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23 | |
Glucose has a molecular weight of 180, sucrose 342, and lactic acid 90. If we dissolve 18 g of glucose, 34 g of sucrose, and 9 g of lactic acid in 1 kg of water, the resulting solution will have a concentration that can be designated (p. 131) |
| | A) | 0.3 M |
| | B) | 3.0 M |
| | C) | 0.1 m |
| | D) | 0.3 Osm |
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24 | |
Glucose has a molecular weight of 180, sucrose 342, and calcium chloride (CaCl2) 111. If we dissolve 18 g of glucose, 34 g of sucrose, and 11 g of CaCl2 in 1 kg of water, the resulting solution will have an osmolality of ____. (Hint: In water, CaCl2 ionizes into Ca2+ and 2 Cl- ions) (p. 131) |
| | A) | 63 Osm |
| | B) | 85 Osm |
| | C) | 300 mOsm |
| | D) | 500 mOsm |
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25 | |
If a sample of plasma were placed in an apparatus to measure its freezing point, and the fluid froze at -1.12° C, we could estimate its osmolality as (p. 133) |
| | A) | 300 mOsm |
| | B) | 112 mOsm |
| | C) | 600 mOsm |
| | D) | 6 Osm |
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26 | |
Which of the following solutions is isotonic relative to blood plasma? (p. 133) |
| | A) | 0.15 m NaCl |
| | B) | 0.9% NaCl |
| | C) | 5% dextrose |
| | D) | all of these are isotonic to plasma |
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27 | |
Two solutions are said to differ in ____ if they have different effects on the osmosis of water. (p. 133) |
| | A) | tonicity |
| | B) | molarity |
| | C) | molality |
| | D) | osmolality |
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28 | |
Red blood cells placed in Ringer's lactate solution will exhibit (p. 133) |
| | A) | swelling |
| | B) | no change |
| | C) | crenation |
| | D) | hemolysis |
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29 | |
Red blood cells placed in a 0.2% NaCl solution will exhibit (p. 133) |
| | A) | shrinkage |
| | B) | no change |
| | C) | crenation |
| | D) | hemolysis |
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30 | |
Red blood cells placed in a 0.3 m urea solution (urea is permeable) will exhibit (p. 133) |
| | A) | shrinkage |
| | B) | no change |
| | C) | crenation |
| | D) | hemolysis |
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31 | |
When the body loses water and the blood becomes too concentrated, it is detected by osmoreceptors located in the (p. 134) |
| | A) | brain |
| | B) | heart |
| | C) | blood vessels |
| | D) | blood cells |
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32 | |
The primary effect of antidiuretic hormone (ADH), is to (p. 134) |
| | 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 |
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33 | |
The carrier proteins of cell membranes have many properties in common with enzymes, including all of the following except (p. 134) |
| | A) | allosteric inhibition |
| | B) | specificity |
| | C) | saturation |
| | D) | competition |
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34 | |
Suppose a carrier protein in a cell membrane can transport amino acid A and amino acid B. It will transport less A per minute when B is present than it will when only A is present, because of (p. 135) |
| | A) | saturation |
| | B) | inhibition |
| | C) | competition |
| | D) | the transport maximum (Tm) |
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35 | |
In diabetes mellitus, the blood glucose level is high (hyperglycemia) and glucose appears in the urine. This is due to a property of the carrier proteins along the kidney tubules, namely (p. 135) |
| | A) | inhibition |
| | B) | inborn error of metabolism |
| | C) | specificity |
| | D) | saturation |
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36 | |
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 (p. 136) |
| | A) | specificity |
| | B) | the need for ATP |
| | C) | competition by other solutes |
| | D) | saturation |
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37 | |
Extracellular fluid (ECF) contains up to 10,000 times more calcium than intracellular fluid (ICF), and yet all cells continue to pump out even more calcium. They could only do this by means of (p. 136) |
| | A) | pinocytosis |
| | B) | facilitated diffusion |
| | C) | osmosis |
| | D) | active transport |
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38 | |
Active transport involves a conformational change in the carrier protein. The most immediate stimulus for this is (p. 136) |
| | 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 |
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39 | |
Na+/K+ pumps are used for all of the following functions, except for the (p. 137) |
| | A) | electrical activity of nerve cells |
| | B) | cotransport of organic molecules |
| | C) | production of body heat |
| | D) | exchange of gases between the cytoplasm and extracellular fluid |
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40 | |
Some cells employ a countertransport (or antiport) mechanism to maintain a high extracellular Ca2+ concentration coupled to the passive inward diffusion of Na+ . This best describes (p. 139) |
| | A) | a membrane which is impermeable to Ca2+ and will not let it into the cell |
| | B) | primary active transport of Ca2+ out of the cell |
| | C) | facilitated diffusion of Ca2+ out of the cell |
| | D) | secondary active transport of Ca2+ out of the cell |
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41 | |
Living cells are negatively charged inside primarily because of (p. 139) |
| | 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 |
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42 | |
The cell membrane is more permeable to ____ than any other cation. (p. 140) |
| | A) | Na+ |
| | B) | K+ |
| | C) | Ca2+ |
| | D) | H+ |
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43 | |
The ratio of concentrations of K+ inside:outside the cell is ____ mEq/L. (p. 139) |
| | A) | 145:12 |
| | B) | 12:145 |
| | C) | 150:5 |
| | D) | 5:150 |
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44 | |
When a cell reaches a potassium equilibrium, (p. 140) |
| | A) | all diffusion of K+ stops |
| | B) | there are equal amounts of K+ ion on both sides of the cell membrane |
| | C) | K+ outward diffusion is balanced by electrical attraction inward |
| | D) | the membrane potential is about +60 mV |
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45 | |
The Nernst equation enables us to calculate the membrane voltage that exactly balances the diffusion of a particular ion down its concentration gradient. To use the equation, however, we must know all of the following, except the (p. 141) |
| | A) | valence of the ion (for example, +1 for potassium; +2 for calcium) |
| | B) | equilibrium potential of the ion in millivolts (mV) |
| | C) | intracellular concentration of the ion in mEq/L |
| | D) | extracellular concentration of the ion in mEq/L |
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46 | |
The sodium equilibrium potential, ENa, is about ____ mV. (p. 141) |
| | A) | +60 |
| | B) | 0 |
| | C) | -65 |
| | D) | -90 |
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47 | |
The EK of a cell is about -90 mV and the ENa is +60 mV. Both potassium and sodium ions contribute to actual resting membrane potential of a cell that is typically about ____mV. (p. 141) |
| | A) | 1. +60 |
| | B) | +75 |
| | C) | 3. -15 |
| | D) | -65 |
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48 | |
Excessive vomiting, for example, can deplete the body's K+ reserves and abnormally lower the potassium concentration in the plasma (hypokalemia). The membrane potential of cells under the influence of hypokalemia would record a value (p. 141) |
| | A) | somewhere between +90 and +120 mV |
| | B) | somewhere between -65 and -90 mV |
| | C) | somewhere between -40 and -65 mV |
| | D) | around +60 mV |
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49 | |
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. (p. 141) |
| | A) | sodium/potassium pump |
| | B) | transport of calcium ions |
| | C) | closure of potassium channels in the membrane |
| | D) | closure of sodium channels in the membrane |
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50 | |
The Na+/K+ pump does not merely compensate for the "leakiness" of the cell membrane to these ions, but actively helps keep the intracellular fluid more negative than the extracellular fluid. This is primarily because (p. 142) |
| | A) | it is involved in cotransport of Ca2+ out of the cell |
| | B) | it helps trap organic anions in the cytoplasm |
| | C) | for every two positive K+ charges it brings into the cell, it transfers three positive Na+ charges out of the cell |
| | D) | for every two anions it pumps out of the cell, it pumps three anions in |
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2002 McGraw-Hill Higher Education