Biology Test 3: Detail View

Denaturation breaks the weak bonds, such as hydrogen bonds and van der Waals interactions, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function.

36)

Which of the following lists ranks these molecules in the correct order by size?protein, water, glucose, sucroseprotein, sucrose, glucose, waterwater, protein, sucrose, glucosewater, sucrose, glucose, proteinglucose, water, sucrose, protein

Protein, sucrose, glucose, water

37)

To what does the term "polypeptide" refer?

None of the listed responses is correct.

38)

Enzyme molecules require a specific shape to perform their catalytic function. Which of the following might alter the shape of an enzymatic protein?

All of the listed responses are correct.

39)

The alpha helix and beta pleated sheet represent which level of protein structure?

Secondary structure

40)

The peptide bond is _____.

A covalent bond joining amino acids together to form a polypeptide

41)

What is the process by which monomers are linked together to form polymers?

Amino acid molecules

42)

The "primary structure" of a protein refers to _____.

The sequence of amino acids

43)

Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form?

Chaperonins

44)

What do Alzheimer's, Parkinson's, and mad cow disease have in common?

All have been associated with the buildup of misfolded proteins in cells.

45)

A glucose molecule is to starch as _____.

A nucleotide is to a nucleic acid

46)

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture _____.

DNA

47)

On the basis of the principle of complementary base pairing, you would expect the percentage of _____ to be equal to the percentage of _____.

Adenine ... thymine

48)

Which of the following are pyrimidines found in the nucleic acid DNA?

Thymine and cytosine

49)

Which of the following describes a difference between DNA and RNA?A.RNA molecules consist of a single polynucleotide chain, whereas DNA molecules consist of two polynucleotide chains organized into a double helix.B.One of their nitrogenous bases is different.C.They contain different sugars.D.The first and second listed responses are correct differences.E.The first three listed responses all describe differences.

E. The first three listed responses all describe differences.

50)

A nucleotide is made of which of the following chemical components?

A nitrogenous base, a phosphate group, and a pentose sugar

51)

Which of the following is true regarding complementary base pairing in DNA and RNA molecules? a.Complementary base pairing within single strands of DNA and RNA gives them particular three-dimensional structures that are necessary for their function. b.Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules. c. Although a DNA molecule demonstrates complementary base pairing between two DNA polynucleotides to form a double helix, an RNA molecule can only base pair along stretches of nucleotides in the same RNA molecule, such as in transfer RNA molecules. d. Complementary base pairing promotes an antiparallel orientation in the structure of DNA and RNA molecules. e.None of the listed responses is correct.

B.Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules.

52)

Which of the following cell structures exhibits selective permeability between a cell and its external environment?

The plasma membrane

53)

Which of the following statements about the role of phospholipids in the structure and function of biological membranes is correct? ( Concept 7.1)

Phospholipids form a selectively permeable structure.

54)

The plasma membrane is referred to as a "fluid mosaic" structure. Which of the following statements about that model is true?

The fluid aspect of the membrane is due to the lateral and rotational movement of phospholipids, and embedded proteins account for the mosaic aspect.

55)

Which of the following types of information is/are most likely to be derived from freeze-fracture of biological samples?

Proteins embedded in membrane bilayers

56)

Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the plasma membrane would cholesterol most likely be found?

In the interior of the membrane

57)

Which of the following functional processes is not a consequence of the association of proteins with biological membranes?

Energy, carbon, and nitrogen storage

58)

Which of the following is a function of membrane proteins and also facilitates tissue formation during embryogenesis?membrane proteins provide receptors for chemical messagesmembrane proteins form channels which move substances across the membranemembrane proteins with short sugar chains form identification tags that are recognized by other cellsmembrane proteins attach the membrane to the cytoskeletonall are correct?

Membrane proteins with short sugar chains form identification tags that are recognized by other cells.

59)

Which of the following statements concerning carbohydrates associated with the plasma membrane is correct?Carbs are only found associated with the membrane of prokaryotic cellsthe carb composition of most eukaryotic plasma membranes is quite similarcarbs on the plasma membrane are typically short chain of between 2 and 5 monosaccaridesmembrane carbs function primarily in cell-cell recognitioncarbs associated with the plasma membrane are located on both surfaces of the membrane

Membrane carbohydrates function primarily in cell-cell recognition.

60)

Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the membrane would carbohydrates most likely be found?

On the outside (external) surface of the membrane

61)

Which statement(s) about the sidedness of the plasma membrane is/are correct?A. every integral membrane protein has a specific orientation in the plasma membraneB. the asymmetrical distribution of membrane proteins, lipids and carbs across the plasma membrane is determined as the membrane is being constructedC.the 2 lipid bi layers may differ in specific lipid compositionD.parts of the proteins that are exposed on the cytoplasmic side of the ER are also exposed on the cytoplasmic side of the plasma membraneE. all

All of the listed responses are correct.

62)

Which of the following molecules is most likely to passively diffuse across the plasma membrane?sodium ionhemoglobinDNAcarbon dioxide glucose

Carbon dioxide

63)

Which of the following would be least likely to diffuse through a plasma membrane without the help of a transport protein? large non polar moleculelarge polar moleculedissolved gasses such as Oxygen or Carbon Dioxidesmall non polar moleculeany of the above would diffuse through the membrane

A large polar molecule

64)

Which of the following structural arrangements of the components in biological membranes is most consistent with membrane's property of selective permeability?A. phospholipid sandwiched between 2 layers of proteinsB. A layer of protein coating a layer of phospholipidC.phospholipid bilayer with proteins scattered on the surface of the membranesD.proteins sandwiched between 2 layers of phospholipidE.proteins embedded in 2 layers of phospholipid

Proteins embedded in two layers of phospholipid

65)

Which of the following statements about passive transport is correct?a.Passive transport permits the solute to move in either direction, but the net movement of the population of solute occurs down the concentration gradient of the molecule.b.Passive transport operates independently of diffusion.c.Passive transport does not occur in the human body.d.Passive transport operates independently of the concentrations of the moving solute.e. In passive transport, solute movement stops when the solute concentration is the same on both sides of the membrane.

Passive transport permits the solute to move in either direction, but the net movement of the population of solute occurs down the concentration gradient of the molecule.

66)

Cells A and B are the same size, shape, and temperature, but cell A is metabolically less active than cell B; cell B is actively converting oxygen to water in cellular respiration. Oxygen will diffuse more rapidly into cell _____ because _____.

B ... the diffusion gradient in cell B is steeper

67)

Which of the following statements about diffusion is true?

It is a passive process.

68)

The internal solute concentration of a plant cell is about 0.8 M. To demonstrate plasmolysis, it would be necessary to suspend the cell in what solution?

1.0 M

69)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?a.The added salt would enter the cell, causing the cell to take up water and swell.b. Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.c.Water would enter the cell by osmosis, and the cell would swell.d.The added salt makes the solution hypotonic compared to the cell. Water will enter the cell by osmosis.e.There would be no osmotic movement of water in response to the added salt.

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

70)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

71)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

72)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

73)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

74)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

75)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

76)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

77)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

78)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

79)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

80)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

81)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

82)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

83)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

84)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

85)

If a red blood cell and a plant cell were placed in seawater, what would happen to the two types of cells?

Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall.

86)

Which of these statements describes some aspect of facilitated diffusion?

Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane.

87)

Which of the following is false in regard to facilitated diffusion?

Facilitated diffusion requires the hydrolysis of ATP.

88)

A selectively permeable membrane separates two solutions. Water is able to pass through this membrane; however, sucrose (a disaccharide) and glucose (a monosaccharide) cannot pass. The membrane separates a 0.2-molar sucrose solution from a 0.2-molar glucose solution. With time, how will the solutions change?

Nothing happens because the two solutions are isotonic to one another.

89)

The concentration of solutes in a red blood cell is about 2%, but red blood cells contain almost no sucrose or urea. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions?

A hypertonic sucrose solution

90)

Green olives may be preserved in brine, which is a 30% salt solution. How does this method of preservation prevent microorganisms from growing in the olives?

A 30% salt solution is hypertonic to the bacteria, so they lose too much water and plasmolyze.

91)

Active transport requires an input of energy and can also generate voltages across membranes. Based on this information, which of the following statements is true?

The sodium/potassium pump hydrolyzes ATP and results in a net charge of +1 outside the cell membrane.

92)

Glucose can be moved into cells via two mechanisms. An active transport mechanism can be used when the concentration of glucose inside the cell is higher than the concentration of glucose outside of the cell. This active transport mechanism moves glucose and sodium into the cell at the same time. The glucose moves up its gradient and the sodium moves down its gradient. Which of the following statements about this mechanism is most true?

The second and third responses are correct.

93)

Which of the following is a correct difference between active transport and facilitated diffusion?

Active transport requires energy from ATP, and facilitated diffusion does not.

94)

Which of the following statements about the sodium-potassium pump is correct?

The sodium-potassium pump is an antiporter that results in a net negative charge inside the cell.

95)

A cell has a membrane potential of -100 mV (more negative inside than outside) and has 1,000 times more calcium ions outside the cell than inside. Which of the following best describes a mechanism by which Ca2+ enters the cell?

Facilitated diffusion of Ca2+ into the cell down its electrochemical gradient

96)

Which of the following correctly describes a general property of all electrogenic pumps?

Create a voltage difference across the membrane

97)

Which of the following correctly describes a general property of all electrogenic pumps?

Create a voltage difference across the membrane

98)

Which of the following statements about cotransport of solutes across a membrane is correct?

Cotransport proteins allow a single ATP-powered pump to drive the active transport of many different solutes.

99)

Consider the transport of protons and sucrose into a plant cell by the sucrose-proton cotransport protein. Plant cells continuously produce a proton gradient by using the energy of ATP hydrolysis to pump protons out of the cell. Why, in the absence of sucrose, don't protons move back into the cell through the sucrose-proton cotransport protein?

The movement of protons through the cotransport protein cannot occur unless sucrose also moves at the same time.

100)

The discomfort associated with irritable bowel syndrome can be alleviated with low doses of the class of antidepressants that block the reuptake of serotonin from the synaptic cleft (the space between adjacent neurons). Serotonin is a relatively small polar neurotransmitter used to transmit nerve impulses in the nerve tissue in the gut and central nervous system. Serotonin is transported back into the releasing neuron up its concentration gradient and down a sodium gradient. How might an antidepressant block serotonin reuptake by the releasing neuron?

It could block active transport of serotonin back into the cell by blocking a serotonin-sodium symporter.

101)

Which of the following enables a cell to pick up and concentrate a specific kind of molecule?

Receptor-mediated endocytosis

102)

Which of the following processes and organelle(s) accounts for the replacement of lipids and proteins lost from the plasma membrane?

Exocytosis and smooth and rough ER

103)

A nursing infant is able to obtain disease-fighting antibodies, which are large protein molecules, from its mother's milk. These molecules probably enter the cells lining the baby's digestive tract via which process?

Endocytosis

104)

Which of the following pairs correctly matches a membrane transport process to its primary function?

Pinocytosis ... the uptake of water and small solutes into the cell by formation of vesicles at the plasma membrane

105)

Which of the following cell structures exhibits selective permeability between a cell and its external environment?

The plasma membrane

106)

Which of the following statements about the role of phospholipids in the structure and function of biological membranes is correct?

Phospholipids form a selectively permeable structure.

107)

The plasma membrane is referred to as a "fluid mosaic" structure. Which of the following statements about that model is true?

The fluid aspect of the membrane is due to the lateral and rotational movement of phospholipids, and embedded proteins account for the mosaic aspect.

108)

Which of the following types of information is/are most likely to be derived from freeze-fracture of biological samples?

Proteins embedded in membrane bilayers

109)

Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the plasma membrane would cholesterol most likely be found

In the interior of the membrane

110)

Which of the following functional processes is not a consequence of the association of proteins with biological membranes?

Energy, carbon, and nitrogen storage

111)

Which of the following is a function of membrane proteins and also facilitates tissue formation during embryogenesis?

Membrane proteins with short sugar chains form identification tags that are recognized by other cells

112)

Which of the following statements concerning carbohydrates associated with the plasma membrane is correct?

Membrane carbohydrates function primarily in cell-cell recognition

113)

Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the membrane would carbohydrates most likely be found?

On the outside (external) surface of the membrane

114)

Which statement(s) about the sidedness of the plasma membrane is/are correct?

All of the listed responses are correct.

115)

Which of the following molecules is most likely to passively diffuse across the plasma membrane?

Carbon dioxide

116)

Which of the following would be least likely to diffuse through a plasma membrane without the help of a transport protein?

A large polar molecule

117)

Which of the following structural arrangements of the components in biological membranes is most consistent with membrane's property of selective permeability?

Proteins embedded in two layers of phospholipid

118)

Which of the following statements about passive transport is correct?

Passive transport permits the solute to move in either direction, but the net movement of the population of solute occurs down the concentration gradient of the molecule.

119)

Cells A and B are the same size, shape, and temperature, but cell A is metabolically less active than cell B; cell B is actively converting oxygen to water in cellular respiration. Oxygen will diffuse more rapidly into cell _____ because _____.

B ... the diffusion gradient in cell B is steeper

120)

Which of the following statements about diffusion is true?

It is a passive process.

121)

The internal solute concentration of a plant cell is about 0.8 M. To demonstrate plasmolysis, it would be necessary to suspend the cell in what solution?

1.0 M

122)

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

123)

If a red blood cell and a plant cell were placed in seawater, what would happen to the two types of cells?

Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall.

124)

Which of these statements describes some aspect of facilitated diffusion?

Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane.

125)

Which of the following is false in regard to facilitated diffusion?

Facilitated diffusion requires the hydrolysis of ATP.

126)

A selectively permeable membrane separates two solutions. Water is able to pass through this membrane; however, sucrose (a disaccharide) and glucose (a monosaccharide) cannot pass. The membrane separates a 0.2-molar sucrose solution from a 0.2-molar glucose solution. With time, how will the solutions change?

Nothing happens because the two solutions are isotonic to one another.

127)

The concentration of solutes in a red blood cell is about 2%, but red blood cells contain almost no sucrose or urea. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions?

A hypertonic sucrose solution

128)

Green olives may be preserved in brine, which is a 30% salt solution. How does this method of preservation prevent microorganisms from growing in the olives?

A 30% salt solution is hypertonic to the bacteria, so they lose too much water and plasmolyze.

129)

Active transport requires an input of energy and can also generate voltages across membranes. Based on this information, which of the following statements is true?

The sodium/potassium pump hydrolyzes ATP and results in a net charge of +1 outside the cell membrane.

130)

Glucose can be moved into cells via two mechanisms. An active transport mechanism can be used when the concentration of glucose inside the cell is higher than the concentration of glucose outside of the cell. This active transport mechanism moves glucose and sodium into the cell at the same time. The glucose moves up its gradient and the sodium moves down its gradient. Which of the following statements about this mechanism is most true? The protein that moves the sodium and glucose into the cell is an antiporter. To pump glucose up its concentration gradient, sodium is moving down its concentration gradient. The sodium forms an electrochemical gradient in this mechanism. The first two responses are correct. The second and third responses are correct.

The second and third responses are correct.

131)

Which of the following is a correct difference between active transport and facilitated diffusion?

Active transport requires energy from ATP, and facilitated diffusion does not.

132)

Which of the following statements about the sodium-potassium pump is correct?

The sodium-potassium pump is an antiporter that results in a net negative charge inside the cell.

133)

A cell has a membrane potential of -100 mV (more negative inside than outside) and has 1,000 times more calcium ions outside the cell than inside. Which of the following best describes a mechanism by which Ca2+ enters the cell?

Facilitated diffusion of Ca2+ into the cell down its electrochemical gradient

134)

Which of the following correctly describes a general property of all electrogenic pumps?

Create a voltage difference across the membrane

135)

Which of the following statements about cotransport of solutes across a membrane is correct?

Cotransport proteins allow a single ATP-powered pump to drive the active transport of many different solutes.

136)

Consider the transport of protons and sucrose into a plant cell by the sucrose-proton cotransport protein. Plant cells continuously produce a proton gradient by using the energy of ATP hydrolysis to pump protons out of the cell. Why, in the absence of sucrose, don't protons move back into the cell through the sucrose-proton cotransport protein?

The movement of protons through the cotransport protein cannot occur unless sucrose also moves at the same time.

137)

The discomfort associated with irritable bowel syndrome can be alleviated with low doses of the class of antidepressants that block the reuptake of serotonin from the synaptic cleft (the space between adjacent neurons). Serotonin is a relatively small polar neurotransmitter used to transmit nerve impulses in the nerve tissue in the gut and central nervous system. Serotonin is transported back into the releasing neuron up its concentration gradient and down a sodium gradient. How might an antidepressant block serotonin reuptake by the releasing neuron?

It could block active transport of serotonin back into the cell by blocking a serotonin-sodium symporter.

138)

Which of the following enables a cell to pick up and concentrate a specific kind of molecule?

Receptor-mediated endocytosis

139)

Which of the following processes and organelle(s) accounts for the replacement of lipids and proteins lost from the plasma membrane?

Exocytosis and smooth and rough ER

140)

A nursing infant is able to obtain disease-fighting antibodies, which are large protein molecules, from its mother's milk. These molecules probably enter the cells lining the baby's digestive tract via which process?

Endocytosis

141)

Which of the following pairs correctly matches a membrane transport process to its primary function?

Pinocytosis ... the uptake of water and small solutes into the cell by formation of vesicles at the plasma membrane

142)

Which of the following correctly states the relationship between anabolic and catabolic pathways?

Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways.

143)

Which of the following situations does not represent an energy transformation?

The coupling of ATP hydrolysis to the production of a proton gradient across a membrane by a proton pump

144)

Organisms are described as thermodynamically open systems. Which of the following statements is consistent with this description?

Organisms acquire energy from, and lose energy to, their surroundings.

145)

Consider the growth of a farmer's crop over a season. Which of the following correctly states a limitation imposed by the first or second law of thermodynamics?

To obey the first law, the crops must represent an open system.

146)

Which of the following states the relevance of the first law of thermodynamics to biology?

Energy can be freely transformed among different forms as long as the total energy is conserved

147)

Which is the most abundant form of energy in a cell?

Chemical energy

148)

Which of the following is an example of the second law of thermodynamics as it applies to biological reactions?

The aerobic respiration of one molecule of glucose produces six molecules each of carbon dioxide and water.

149)

According to the second law of thermodynamics, which of the following is true?

The decrease in entropy associated with life must be compensated for by increased entropy in the environment in which life exists.

150)

If the entropy of a living organism is decreasing, which of the following is most likely to be occurring simultaneously?

Energy input into the organism must be occurring to drive the decrease in entropy.