BIO FINAL DIFFICULT QUESTIONS
Which of the following functional groups is present in all amino acids? —COH —OH —SH —NH2
-NH2
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? distilled water 1.0 M 150 mM. 0.8 M 0.4 M
1.0 M
A neutral atom of chlorine has an atomic number of 17. It has __________ electrons in its third shell. 2 7 8 17
7
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? High salt concentration raises the pH, thus inhibiting bacterial metabolism. Bacterial cells shrivel up in high salt solutions, causing the cell to burst. A 30% salt solution is hypertonic to the bacteria, so they lose too much water and undergo plasmolysis. A 30% salt solution is hypotonic to the bacteria, so they gain too much water and burst. High salt concentration lowers the pH, thus inhibiting bacterial metabolism.
A 30% salt solution is hypertonic to the bacteria, so they lose too much water and undergo plasmolysis.
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 a large, nonpolar molecule a small, nonpolar molecule dissolved gases such as oxygen or carbon dioxide Any of the listed molecules would easily diffuse through the membrane.
A large, polar molecule
What is ATP's importance in the cell? ATP contains a long hydrocarbon tail and is important in storing energy. ATP can add phosphate groups, thereby releasing energy that can be used in cellular processes. ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes. ATP stores energy in carbonyl groups. When a carbonyl group is removed, energy is released to be used in cellular processes.
ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes.
Which of the following is a correct difference between active transport and facilitated diffusion? Facilitated diffusion requires carrier proteins, but active transport requires channel proteins. Facilitated diffusion can move solutes against a concentration gradient, and active transport cannot. Facilitated diffusion involves transport proteins, and active transport does not. Active transport requires energy from ATP, and facilitated diffusion does not. Active transport involves transport proteins, and facilitated diffusion does not.
Active transport requires energy from ATP, and facilitated diffusion does not.
hat do Alzheimer's, Parkinson's, and mad cow disease have in common? All are associated with the buildup of lipids in brain cells due to faulty lysosome activity. All are associated with plaque buildup in arteries (atherosclerosis). All are caused by the buildup of misfolded proteins in cells. All are associated with the buildup of misfolded proteins in cells. All cause the misfolding of nucleic acids.
All are associated with the buildup of misfolded proteins in cells.
What do cohesion, surface tension, and adhesion have in common with reference to water? All are properties related to hydrogen bonding. All are produced by covalent bonding. All have to do with ionic interactions. All are results of the structure of the hydrogen atom.
All are properties related to hydrogen bonding.
Which statements about the sidedness of the plasma membrane is correct?The asymmetrical distribution of membrane proteins, lipids, and carbohydrates across the plasma membrane is determined as the membrane is being constructed. The two lipid layers may differ in specific lipid composition. Every integral membrane protein has a specific orientation in the plasma membrane. Parts of proteins that are exposed on the cytoplasmic side of the endoplasmic reticulum are also exposed on the cytoplasmic side of the plasma membrane. All of the listed responses are correct.
All of the listed responses are correct
Which of the following functional groups increases the solubility of organic compounds in water? —COH —COOH —OH All of the listed responses are correct.
All of the listed responses are correct.
Which of the following is true regarding complementary base pairing in DNA and RNA molecules? 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. Complementary base pairing within single strands of DNA and RNA gives them particular three-dimensional structures that are necessary for their function. Although a DNA molecule demonstrates complementary base pairing between two DNA polynucleotides to form a double helix, an RNA molecule can base-pair only along stretches of nucleotides in the same RNA molecule, such as in transfer RNA molecules. Complementary base pairing promotes an antiparallel orientation in the structure of DNA and RNA molecules. None of the listed responses is correct.
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.
What is the role of van der Waals interactions in biological molecules? Van der Waals interactions are strong bonds that play a major structural role in holding proteins together. Van der Waals interactions are too weak to be significant. Although they are weak bonds, van der Waals interactions help to reinforce the three-dimensional shapes of large molecules. Van der Waals interactions are important only in water.
Although they are weak bonds, van der Waals interactions help to reinforce the three-dimensional shapes of large molecules.
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. The flow of energy between catabolic and anabolic pathways is reversible. Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways. Catabolic pathways produce usable cellular energy by synthesizing more complex organic molecules. Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways.
Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways.
Cells A and B are the same size, shape, and temperature, but cell A is metabolically less active than cell B. and 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 B ... the gradient of oxygen is oriented in the opposite direction compared to cell A A ... its membrane transport proteins will not be saturated A ... the concentration gradient there is shallower B ... the oxygen molecules inside cell B have a higher kinetic energy
B ... the diffusion gradient in cell B is steeper
Seawater is hypertonic to cytoplasm in vertebrate cells and in plant cells. If a red blood cell and a plant cell were placed in seawater, what would happen to the two types of cells? The red blood cell would shrink, and the plant cell would gain water. The red blood cell would burst, and the plant cell would shrink. Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall. Both cells would gain water by osmosis; the red blood cell would burst, and the plant cell would increase in turgor pressure. Both cells will gain water, but cell walls will prevent both cells from bursting.
Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall
Which of the following statements is true about cell fractionation? Cell fractionation requires the use of a scanning electron microscope. Cell fractionation uses strong acids to break apart cells. Cell fractionation separates cells into their component parts. Cell fractionation is no longer used in modern cell biology. None of the listed responses is correct.
Cell fractionation separates cells into their component parts.
Which of the following structures is found in animal cells but NOT in plant cells? plasma membrane Golgi apparatus centrioles rough endoplasmic reticulum mitochondria
Centrioles
The phenomenon responsible for maintaining the upward movement of water through vessels in a tree is __________. surface tension hydration shells specific heat cohesion
Cohesion
Which statement about the cytoskeleton is true? Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm. Microfilaments are more permanent structures in cells compared to intermediate filaments and microtubules. Plant cells lack a cytoskeleton because they have a rigid cell wall. Intermediate filaments are hollow tubes of protein that provide structural support. Microtubules are chains of proteins that resist stretching.
Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm.
Which of the following statements about cotransport of solutes across a membrane is correct? The sodium-potassium pump is an example of a cotransport protein. In cotransport, both solutes that are being transported are moving down their chemical gradients. A cotransport protein is most commonly an ion channel. Cotransport proteins allow a single ATP-powered pump to drive the active transport of many different solutes. Cotransport involves the hydrolysis of ATP by the transporting protein.
Cotransport proteins allow a single ATP-powered pump to drive the active transport of many different solutes.
A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture __________. cellulose fatty acids sucrose DNA proteins
DNA
What is the reason carbon atoms are the most versatile building blocks of the molecules used by living organisms? Carbon is the central atom of carbon dioxide, a necessary molecule for photosynthesis. Carbon is the central atom in urea, a molecule used by many living organisms to transport wastes from the body. Each carbon atom acts as an intersection point from which a molecule can branch off in up to four directions. All of the listed responses are correct.
Each carbon atom acts as an intersection point from which a molecule can branch off in up to four directions.
Which of the following correctly describes a general property of all electrogenic pumps? Electrogenic pumps result in a cell with a high internal concentration of protons. Electrogenic pumps pump sodium out of the cell and potassium into the cell. Electrogenic pumps can pump a large variety of solutes across a membrane against their concentration gradient. Electrogenic pumps create a voltage difference across the membrane. Electrogenic pumps result in a cell with an interior that is positively charged relative to the outside of the cell.
Electrogenic pumps create a voltage difference across the membrane.
Which of the following has negligible mass? Electron Atom Proton Neutron
Electron
Which of the following states the relevance of the first law of thermodynamics to biology? Living organisms must increase the entropy of their surroundings. Photosynthetic organisms produce energy in sugars from sunlight. Energy is destroyed as glucose is broken down during cellular respiration Because living things consume energy, the total energy of the universe is constantly decreasing. Energy can be freely transformed among different forms as long as the total energy is conserved.
Energy can be freely transformed among different forms as long as the total energy is conserved.
In terms of cellular function, what is the most important difference between prokaryotic and eukaryotic cells? Eukaryotic cells are much more successful than prokaryotic cells. Eukaryotic cells are larger than prokaryotic cells. Eukaryotic cells are compartmentalized, which allows for specialization. Eukaryotic cells lack many of the organelles found in prokaryotes. Eukaryotic cells can synthesize proteins but prokaryotic cells cannot.
Eukaryotic cells are compartmentalized, which allows for specialization
Which of these statements describes some aspect of facilitated diffusion? Facilitated diffusion is another name for osmosis. Facilitated diffusion of solutes occurs through phospholipid pores in the membrane. There is only one kind of protein pore for facilitated diffusion. Facilitated diffusion requires energy to drive a concentration gradient. Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane.
Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane.
Which of the following is FALSE in regard to facilitated diffusion? Facilitated diffusion can occur by means of transport proteins. Facilitated diffusion requires a concentration gradient. Facilitated diffusion can move ions across membranes. Facilitated diffusion requires the hydrolysis of ATP. Facilitated diffusion can occur through protein channels.
Facilitated diffusion requires the hydrolysis of ATP.
Nutritionally, saturated triacylglycerols are considered to be less healthful than unsaturated triacylglycerols. What is the difference between them? Saturated triacylglycerols have more double bonds than unsaturated triacylglycerols do. Saturated triacylglycerols are liquid at room temperature. Saturated triacylglycerols are fats; unsaturated triacylglycerols are carbohydrates. For carbon skeletons of equal length, saturated triacylglycerols have more hydrogen atoms than unsaturated triacylglycerols do. All of the listed responses are correct.
For carbon skeletons of equal length, saturated triacylglycerols have more hydrogen atoms than unsaturated triacylglycerols do.
Microtubules and microfilaments commonly work with which of the following to perform many of their functions? ribosomes RNA Golgi apparatus lysosomes None of the listed responses is correct.
Golgi Apparatus
Which of the following sequences represents the order in which a protein made in the rough endoplasmic reticulum might move through the endomembrane system? lysosome → plasma membrane Golgi apparatus → lysosome Golgi apparatus → mitochondria nuclear envelope → lysosome plasma membrane → nuclear envelope
Golgi apparatus → lysosome
Which of the following statements about diffusion is true? It requires expenditure of energy by the cell. It always requires integral proteins of the cell membrane. It is a passive process. It involves only the movement of water molecules. It occurs when molecules move from a region of lower concentration to a region of higher concentration.
It is a passive process
Which of the following statements concerning carbohydrates associated with the plasma membrane is correct? Membrane carbohydrates function primarily in cell-cell recognition. Carbohydrates on the plasma membrane are typically long, complex chains of several dozen monosaccharides. Carbohydrates associated with the plasma membrane are located on both surfaces of the membrane. The carbohydrate composition of most eukaryotic plasma membranes is quite similar. Carbohydrates are found associated with the membranes of prokaryotic cells only.
Membrane carbohydrates function primarily in cell-cell recognition.
Which of the following functions of membrane proteins is important in tissue formation during embryonic development in animals? Membrane proteins attach the membrane to the cytoskeleton. Membrane proteins form channels, which move substances across the membrane. Membrane proteins with short sugar chains form identification tags that are recognized by other cells. Membrane proteins possess enzymatic activity. All of the listed responses are correct.
Membrane proteins with short sugar chains form identification tags that are recognized by other cells
Which of the following is FALSE? The folds of the inner mitochondrial membrane are called cristae. Mitochondria are involved in energy metabolism. Mitochondria possess their own DNA. Mitochondria have more than one membrane. Mitochondria contain ribosomes in the intermembrane space.
Mitochondria contain ribosomes in the intermembrane space.
Why is the increasing amount of carbon dioxide being taken up by the oceans a cause for concern? There is no cause for concern. Carbonic acid (H2CO3) is an excellent buffer and will help keep the pH of seawater constant. More carbon dioxide causes an increase in carbonic acid (H2CO3), which leads to an increase in the concentration of carbonate ion (CO32-). More carbon dioxide causes an increase in carbonic acid (H2CO3), which leads to a decrease in the concentration of carbonate ion (CO32-). The buffering action of carbonic acid (H2CO3) causes the pH of seawater to rise.
More carbon dioxide causes an increase in carbonic acid (H2CO3), which leads to a decrease in the concentration of carbonate ion (CO32-).
Which of these is a thiol? —OH —COH —SH None of the listed responses is correct.
None of the listed responses is correct
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? After the sucrose dissociates into two monosaccharides, water will move via osmosis to the side of the membrane that contains the dissociated sucrose. The sucrose solution is hypertonic and will gain water because the total mass of sucrose is greater than that of glucose. Water will leave the sucrose solution because the sucrose molecule is a disaccharide and, thus, larger than the monosaccharide glucose. Water will enter the sucrose solution because the sucrose molecule is a disaccharide and, thus, larger than the monosaccharide glucose. Nothing will happen, because the two solutions are isotonic to one another.
Nothing will happen, because the two solutions are isotonic to one another.
Organisms are described as thermodynamically open systems. Which of the following statements is consistent with this description? The metabolism of an organism is isolated from its surroundings. Because energy must be conserved, organisms constantly recycle energy and thus need no input of energy. Heat produced by the organism is conserved in the organism and not lost to the environment. Organisms acquire energy from, and lose energy to, their surroundings. All of the listed responses are correct.
Organisms acquire energy from, and lose energy to, their surroundings.
Which of the following statements about passive transport is correct? Passive transport operates independently of diffusion. Passive transport permits the solute to move in either direction, but the net movement of solute molecules occurs down the concentration gradient of the molecule. Passive transport operates independently of the concentrations of the moving solute. In passive transport, solute movement stops when the solute concentration is the same on both sides of the membrane. Passive transport does not occur in the human body.
Passive transport permits the solute to move in either direction, but the net movement of solute molecules occurs down the concentration gradient of the molecule.
Which of the following statements about the role of phospholipids in the structure and function of biological membranes is correct? They are triacylglycerols, which are commonly available in foods. Phospholipids form a single sheet in water. Phospholipids form a structure in which the hydrophobic portion faces outward. Phospholipids are completely unable to interact with water. Phospholipids form a selectively permeable structure.
Phospholipids form a selectively permeable structure.
Which of the following molecules has a carboxyl functional group? R—OPO3-2 R—COOH R—COH R—NH2
R-COOH
Which of the following molecules is a weak acid? R—NH2 R—COOH R—SH R—OH
R-COOH
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. All types of cellular respiration produce ATP. Cellular respiration releases some energy as heat. The first and second choices are correct. The first, second, and third choices are correct.
The aerobic respiration of one molecule of glucose produces six molecules each of carbon dioxide and water.
Which of the following examples best describes a unique functional property of the carboxyl group? Two carboxyl groups can bond covalently to help stabilize protein structure. The covalent bond between oxygen and hydrogen is so polar that hydrogen ions tend to dissociate from oxygen reversibly. It is polar as a result of the electronegative oxygen atom drawing electrons toward it. Its compounds may be structural isomers with different properties.
The covalent bond between oxygen and hydrogen is so polar that hydrogen ions tend to dissociate from oxygen reversibly.
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 behavior of phospholipids, and the mosaic aspect is due to the presence of carbohydrates. The fluid aspect of the membrane is due to the lateral and rotational movement of phospholipids, and embedded proteins account for the mosaic aspect. The fluid aspect of the membrane describes its structure at normal temperatures, and the mosaic aspect describes the behavior of the membrane as the temperature is lowered. The mosaic aspect of the membrane is due to the glycosylation of phospholipids on the cytoplasmic side of the membrane. Only phospholipids are capable of moving in the membrane.
The fluid aspect of the membrane is due to the lateral and rotational movement of phospholipids, and embedded proteins account for the mosaic aspect
A pharmaceutical company was forced to recall a pain reliever medication that had been linked to the fatalities of several hundred people. Analysis of the recalled drug revealed the presence of two isomers due to an asymmetrical carbon atom in the drug molecule. What can be hypothesized from this observation? The isomers are enantiomers, with one having toxic effects on humans. The asymmetrical carbon causes the solubility of the two drug isomers to vary significantly, thus having different chemical properties and effects on people who take them. The two isomers of the drug contain different functional groups and the isomer with the aberrant functional group is connected to the fatalities. The double bond involving the asymmetrical carbon can generate cis-trans isomers that typically have different chemical properties, thus accounting for the drug's toxic properties.
The isomers are enantiomers, with one having toxic effects on humans.
Amylase is an enzyme that breaks down starch. Why cannot the same enzyme break down cellulose? Cellulose molecules are much too large. The bonds between the monosaccharide monomers in cellulose are much stronger. Starch is made of glucose; cellulose is made of fructose. The monosaccharide monomers in cellulose are bonded together differently than those in starch. The enzyme cannot attack cellulose because of its helical shape.
The monosaccharide monomers in cellulose are bonded together differently than those in starch.
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, do protons not move back into the cell through the sucrose-proton cotransport protein? Protons are freely permeable through the phospholipid bilayer, so no transport protein is needed for protons. In the absence of sucrose, the ATP-powered proton pump does not function, so there is no proton gradient. Protons, unlike other substances, do not diffuse down their electrochemical gradient. The movement of protons through the cotransport protein cannot occur unless sucrose moves at the same time.
The movement of protons through the cotransport protein cannot occur unless sucrose moves at the same time.
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? Active transport can use ATP as its energy source and ensures that there is no voltage across the cell membrane. Active transport uses channel proteins and ensures that the interior of the cell is always positive compared to the exterior of the cell. Active transport moves solutes down their concentration gradients and always uses ATP as the source of energy to do this. The sodium-potassium pump hydrolyzes ATP and results in a net positive change outside the cell membrane. The source of energy for active transport of a solute up its gradient can be ATP or a concentration gradient of a second solute. This second gradient of solutes maintains no net difference in voltage across the membrane.
The sodium-potassium pump hydrolyzes ATP and results in a net positive change outside the cell membrane.
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? The process of photosynthesis produces energy that the plant uses to grow. To obey the first law, the crops must represent an open system. The entropy of the universe must decrease to account for the increased entropy associated with plant growth. Growth of the crops must occur spontaneously. All of the listed responses are correct.
To obey the first law, the crops must represent an open system.
Glucose can be moved into cells via an active transport mechanism 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 accurate? To pump glucose up its concentration gradient, sodium moves down its concentration gradient. Sodium and glucose move together into the cell via facilitated diffusion. The distribution of sodium ions across the membrane forms an electrochemical gradient that drives this mechanism. Sodium and glucose move together into the cell via facilitated diffusion, and to pump glucose up its concentration gradient, sodium moves down its concentration gradient. To pump glucose up its concentration gradient, sodium moves down its concentration gradient, and the distribution of sodium ions across the membrane forms an electrochemical gradient that drives this mechanism.
To pump glucose up its concentration gradient, sodium moves down its concentration gradient, and the distribution of sodium ions across the membrane forms an electrochemical gradient that drives this mechanism.
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 enter the cell by osmosis, and the cell would swell. The added salt makes the solution hypotonic compared to the cell. Water will enter the cell by osmosis. The added salt would enter the cell, causing the cell to take up water and swell. 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
Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.
The peptide bond is __________. a covalent bond joining simple sugars together to form a polypeptide a covalent bond joining nucleotides together to form a nucleic acid a hydrogen bond joining nucleotides together to form a nucleic acid a hydrogen bond joining amino acids together to form a polypeptide a covalent bond joining amino acids together to form a polypeptide
a covalent bond joining amino acids together to form a polypeptide
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 hypotonic urea solution a hypotonic sucrose solution a hypertonic sucrose solution a hypertonic urea solution pure water
a hypertonic sucrose solution
Which of the following lists represents the chemical components of a nucleotide? a nitrogenous base, an amino acid, and a phosphate group a series of nitrogenous bases, a nucleic acid backbone, and a hexose sugar a nitrogenous base, a phosphate group, and a pentose sugar a nitrogenous base, an amino acid, and a pentose sugar a nitrogenous base, a fatty acid, and an amino acid
a nitrogenous base, a phosphate group, and a pentose sugar
A glucose molecule is to starch as __________. a nucleic acid is to a polypeptide a steroid is to a lipid a protein is to an amino acid an amino acid is to a nucleic acid a nucleotide is to a nucleic acid
a nucleotide is to a nucleic acid
In a hydrolysis reaction, __________, and in this process water is __________. monomers are assembled to produce a polymer ... produced a polymer is broken up into its constituent monomers ... produced monomers are assembled to produce a polymer ... consumed a polymer is broken up into its constituent monomers ... consumed a monomer is broken up into its constituent polymers ... produced
a polymer is broken up into its constituent monomers ... consumed
The most common form of calcium has 20 protons, 20 neutrons, and 20 electrons. Which of the following elements would be an isotope of calcium? an atom with 20 protons, 20 neutrons, and 18 electrons an atom with 21 protons, 20 neutrons, and 21 electrons an atom with 20 protons, 21 neutrons, and 20 electrons an atom with 21 protons, 21 neutrons, and 21 electrons
an atom with 20 protons, 21 neutrons, and 20 electrons
Ionic bonds form as a result of __________. unequal sharing of electrons between atoms attraction between a hydrogen and other atoms that share electrons unequally sharing of electron pairs between atoms attraction between ions that have opposite charges
attraction between ions that have opposite charges
Consider two cells with the same volume but with very different surface areas due to differences in their shapes. The cell with the larger surface area is likely to __________. have a very high metabolic rate be a prokaryotic cell be nearly spherical in shape be buried deep in the interior of an organism be involved in the rapid uptake of compounds from the cell's environment
be involved in the rapid uptake of compounds from the cell's environment
Which of the following statements correctly describes a common characteristic of a plant cell wall and an animal cell extracellular matrix? Both are permeable to water and small solutes. Both contain large amounts of collagen. Both are composed primarily of carbohydrates. Both are permeable to water and small solutes, and both contain large amounts of collagen. Both are permeable to water and small solutes, both contain large amounts of collagen, and both are composed primarily of carbohydrates.
both are permeable to water and small solutes
Which of the following molecules is most likely to passively diffuse across the plasma membrane? hemoglobin DNA glucose carbon dioxide sodium ion
carbon dioxide
Which functional group would you predict is part of abscisic acid? hydroxyl group amino group carboxyl group carbonyl group
carboxyl group
Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form? chaperonins enzymes receptor proteins antibodies fibrous proteins
chaperonins
Basal bodies are most closely associated with which of the following cell components? cilia nucleus mitochondria Golgi apparatus the central vacuole
cilia
Consider a protein that is made in the rough endoplasmic reticulum. You observe that when the synthesis of the protein is completed, the protein is located in the ER membrane. Where else in the cell might this protein be found? in a mitochondrion, functioning in ATP synthesis embedded in the plasma membrane, functioning in the transport of molecules into the cell in the aqueous interior of a lysosome, functioning as a digestive enzyme in the internal space of the Golgi apparatus, being modified before the protein is excreted in the cytoplasm, functioning as an enzyme in carbohydrate synthesis
embedded in the plasma membrane, functioning in the transport of molecules into the cell
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? active transport osmosis exocytosis endocytosis passive transport
endocytosis
Which of the following is NOT a function of membrane proteins? enzymatic activity intercellular joining cell-cell recognition transport energy, carbon, and nitrogen storage
energy, carbon, and nitrogen storage
Which of the following processes and organelles account for the replacement of lipids and proteins lost from the plasma membrane? flip-flop of phospholipids from one side of the plasma membrane to the other and the Golgi exocytosis and smooth ER and rough ER active transport and the rough ER receptor-mediated endocytosis and smooth ER and Golgi endocytosis and Golgi
exocytosis and smooth ER and rough ER
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? movement of Ca2+ into the cell through an ion channel down its concentration gradient cotransport of Ca2+ into the cell with Cl- movement of Ca2+ into the cell through a carrier protein down its electrical gradient passive diffusion of Ca2+ into the cell down its electrochemical gradient facilitated diffusion of Ca2+ into the cell down its electrochemical gradient
facilitated diffusion of Ca2+ into the cell down its electrochemical gradient
The subunits (monomers) in cellulose are linked together by __________. glycosidic linkages phosphodiester linkages peptide bonds ester linkages ionic bonds
glycosidic linkages
The fatty acid tails of a phospholipid are __________ because they __________. hydrophilic ... are easily hydrolyzed into their monomers hydrophobic ... dissolve easily in water hydrophobic ... have no charges to which water molecules can adhere hydrophobic ... consist of units assembled by dehydration reactions hydrophilic ... consist of units assembled by dehydration reactions
hydrophobic ... have no charges to which water molecules can adhere
Which of the following are properties of hydrocarbons? hydrophobic, nonpolar, good source of stored energy hydrophilic, good source of stored energy, consisting primarily of carbon and hydrogen hydrophilic, containing numerous carboxyl groups, nonpolar hydrophobic, polar, charged
hydrophobic, nonpolar, good source of stored energy
Chloroplasts and mitochondria are thought to be of prokaryotic origin. One piece of evidence that supports this hypothesis is that these organelles contain prokaryotic-like ribosomes. These ribosomes are probably most similar to ribosomes found __________. in bacterial cells on the rough ER free in the cytoplasm of eukaryotes free in the cytoplasm of eukaryotes and on the rough ER free in the cytoplasm of eukaryotes, on the rough ER, and in bacterial cells
in bacterial cells
Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the plasma membrane would cholesterol most likely be found? on either surface of the membrane, but not in the interior of the membrane in the interior of the membrane on the inside (cytoplasmic) surface on the outside (external) surface of the membrane in the interior and on the inside surface, but not on the outside surface
in the interior of the membrane
Adding acid tends to ____ of a solution. increase the hydrogen ion concentration and lower the pH decrease the hydrogen ion concentration and raise the pH decrease the hydrogen ion concentration and lower the pH increase the hydrogen ion concentration and raise the pH
increase the hydrogen ion concentration and lower the pH
When the proton number and electron number are unequal, the atom or molecule __________. is an ion forms a covalent bond with another atom becomes part of a molecule gains or loses a proton
is an ion
The sex hormones estradiol and testosterone belong to which class of molecules? lipids nucleic acids carbohydrates proteins amino acids
lipids
Which of the following categories best describes the function of the rough endoplasmic reticulum? manufacturing structural support of cells energy processing information storage breakdown of complex foods
manufacturing
Which of the following structures is found in eukaryotic but NOT prokaryotic cells? DNA mitochondria ribosomes plasma membrane cytosol
mitochondria
Which of the following five membranes is most likely to have a lipid composition that is distinct from those of the other four? lysosome membrane plasma membrane Golgi apparatus endoplasmic reticulum mitochondrial outer membrane
mitochondrial outer membrane
Cilia and flagella move due to the interaction of the cytoskeleton with which of the following? mitochondria tubulin actin motor proteins pseudopodia
motor proteins
Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the membrane would carbohydrates most likely be found? on the inside (cytoplasmic) surface of the membrane on the outside (external) surface of the membrane in the interior of the membrane on both hydrophilic surfaces of the membrane but not in the hydrophobic interior Carbohydrates are rarely associated with plasma membranes.
on the outside (external) surface of the membrane
Which of the following functional groups is associated with a release of energy when removed from the carbon skeleton with water? amino group sulfhydryl group hydroxyl group phosphate group
phosphate group
Which of the following pairs correctly matches a membrane transport process to its primary function? exocytosis: the movement of water and solutes out of the cell by passage through the plasma membrane phagocytosis: secretion of large particles from the cell by fusion of vesicles with the plasma membrane pinocytosis: the uptake of water and small solutes into the cell by formation of vesicles at the plasma membrane osmosis: passive diffusion of water and small solutes across a membrane None of the listed responses is correct.
pinocytosis: the uptake of water and small solutes into the cell by formation of vesicles at the plasma membrane
Dye injected into a plant cell might be able to enter an adjacent cell through __________. a tight junction a microtubule a cell wall plasmodesmata a gap junction
plasmodesmata
Which of the following enables a cell to pick up and concentrate a specific kind of molecule? facilitated diffusion channel proteins osmosis passive transport receptor-mediated endocytosis
receptor-mediated endocytosis
Which of the following organelles might be found inside other organelles? ribosomes the nucleolus mitochondria transport vesicles No organelles are found inside of other organelles
ribosomes
You would expect a cell with an extensive Golgi apparatus to __________. secrete large amounts of protein store large quantities of ions make large amounts of ATP absorb nutrients in the GI tract move rapidly
secrete large amounts of protein
The overall three-dimensional shape of a single polypeptide is called its __________. double helix primary structure secondary structure quaternary structure tertiary structure
tertiary structure
The amount of heat required to convert 1 g of any substance from the liquid to the gaseous state is defined as __________. 1 calorie surface tension the heat of vaporization of that substance the specific heat of that substance
the heat of vaporization of that substance
A dish of animal cells was grown in the presence of radioactive phosphorous. The phosphorous largely ended up in nucleotides inside the actively growing animal cells. In which cellular structure or structures would you predict the majority of the radioactive phosphorous to accumulate? rough endoplasmic reticulum the Golgi apparatus the nucleus rough endoplasmic reticulum and Golgi apparatus the Golgi apparatus and the nucleus
the nucleus
In a group of water molecules, hydrogen bonds form between which of the following? the oxygen atom in one water molecule and a hydrogen atom in another water molecule the hydrogen atoms in a single water molecule two hydrogen atoms in different water molecules the oxygen atoms in different water molecules
the oxygen atom in one water molecule and a hydrogen atom in another water molecule
The "primary structure" of a protein refers to __________. the weak aggregation of two or more polypeptide chains into one functional macromolecule interactions among the side chains or R groups of the amino acids the α helix or β pleated sheets coiling due to hydrogen bonding between amino acids the sequence of amino acids along a polypeptide chain
the sequence of amino acids along a polypeptide chain
The amount of heat required to change the temperature of 1 g of any substance by 1°C is defined as __________. 1 kilocalorie the heat of vaporization of that substance the specific heat of that substance 1 calorie
the specific heat of that substance
Which of the following are pyrimidines found in the nucleic acid DNA adenine and guanine thymine and adenine thymine and cytosine guanine and cytosine uracil and guanine
thymine and cytosine
A molecule has one carbon-carbon double bond and four monovalent atoms or groups. How many different cis-trans isomers exist for this molecule? none two four six
two
When do hydrogen bonds occur? when a molecule with partial charges contacts a molecule without partial charges when two atoms achieve stable electron configurations by sharing electrons with each other when partial opposite charges on molecules come close enough to attract each other when a molecule with a low molecular weight is bonded to a molecule with a high molecular weight
when partial opposite charges on molecules come close enough to attract each other