AP Bio 1st 6 Weeks Test Review
(1) About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make
up approximately 96% of living matter?
A) carbon, sodium, chlorine, nitrogen B) carbon, sulfur, phosphorus, hydrogen
C) oxygen, hydrogen, calcium, sodium D) carbon, hydrogen, nitrogen, oxygen
E) carbon, oxygen, sulfur, calcium
(2) Calcium has an atomic number of 20 and an atomic mass of 40. Therefore, a calcium atom must have
A) 20 protons. B) 40 electrons. C) 40 neutrons. D) A and B only E) A, B, and C
(3) Different atomic forms of an element contain the same number of protons but a different number of neutrons.
What are these different atomic forms called?
A) ions B) isotopes C) neutronic atoms D) isomers E) radioactive atoms
(4) Electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a
possible result is that
A) an electron may move to an electron shell farther out from the nucleus.
B) an electron may move to an electron shell closer to the nucleus.
C) the atom may become a radioactive isotope.
D) the atom would become a positively charged ion, or cation.
E) the atom would become a negatively charged ion, or anion.
Questions 5-8 refer to the following diagram.
(5) Which drawing depicts the electron configuration of neon?
(6) Which drawing depicts the electron configuration of oxygen?
(7) Which drawing depicts the electron configuration of nitrogen?
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(8) Which of the following takes place as an ice cube cools a drink?
A) Molecular collisions in the drink increase. B) Kinetic energy in the drink decreases.
C) A calorie of heat energy is transferred from the ice to the water of the drink.
D) The specific heat of the water in the drink decreases E) Evaporation of the water in the drink increases.
(9) How many electrons would be expected in the outermost electron shell of an atom with atomic number 12?
A) 1 B) 2 C) 4 D) 6 E) 8
(10) What is the maximum number of covalent bonds an element with atomic number 8 can make with hydrogen?
A) 1 B) 2 C) 3 D) 4 E) 6
(11) If an atom of sulfur (atomic number 16) were allowed to react with atoms of hydrogen (atomic number 1),
which of the molecules below would be formed?
(12) Nitrogen (N) is much more electronegative than hydrogen (H). Which of the following statements is correct
about the atoms in ammonia (NH3)?
A) Each hydrogen atom has a partial positive charge. B) The nitrogen atom has a strong positive charge.
C) Each hydrogen atom has a slight negative charge. D) The nitrogen atom has a partial positive charge.
E) There are covalent bonds between the hydrogen atoms.
(13) What is the difference between covalent bonds and ionic bonds?
A) Covalent bonds involve the sharing of protons between atoms, and ionic bonds involve the sharing of
electrons between atoms.
B) Covalent bonds involve the sharing of neutrons between atoms, and ionic bonds involve the sharing of
electrons between atoms.
C) Covalent bonds involve the sharing of electrons between atoms, and ionic bonds involve the electrical
attraction between atoms.
D) Covalent bonds involve the sharing of protons between atoms, and ionic bonds involve the sharing of
neutrons between atoms.
E) Covalent bonds involve the transfer of electrons between atoms, and ionic bonds involve the sharing of
neutrons between atoms.
(14) Van der Waals interactions result when
A) hybrid orbitals overlap. B) electrons are not symmetrically distributed in a molecule.
C) molecules held by ionic bonds react with water. D) two polar covalent bonds react.
E) a hydrogen atom loses an electron.
(15) Which of the following is not considered to be a weak molecular interaction?
A) a covalent bond B) a van der Waals interaction C) an ionic bond in the presence of water
D) a hydrogen bond E) A and B only
(16) Sometimes atoms form molecules by sharing two pairs of valence electrons. When this occurs, the atoms are
said to be joined by
A) a double covalent bond. B) an electronegative bond. C) a hydrogen bond. D) a protonic bond.
E) a complex bond.
(17) The slight negative charge at one end of one water molecule is attracted to the slight positive charge of
another water molecule. What is this attraction called?
A) a covalent bond B) a hydrogen bond C) an ionic bond D) a hydrophilic bond E) a hydrophobic bond
(18) Which of the following effects is produced by the high surface tension of water?
A) Lakes donʹt freeze solid in winter, despite low temperatures.
B) A water strider can walk across the surface of a small pond.
C) Organisms resist temperature changes, although they give off heat due to chemical reactions.
D) Water can act as a solvent.
E) The pH of water remains exactly neutral.
(19) Which of the following statements correctly defines a kilocalorie?
A) the amount of heat required to raise the temperature of 1 g of water by 1°F
B) the amount of heat required to raise the temperature of 1 g of water by 1°C
C) the amount of heat required to raise the temperature of 1 kg of water by 1°F
D) the amount of heat required to raise the temperature of 1 kg of water by 1°C
E) the amount of heat required to raise the temperature of 1,000 g of water by 1°F
(20) Waterʹs high specific heat is mainly a consequence of the
A) small size of the water molecules. B) high specific heat of oxygen and hydrogen atoms.
C) absorption and release of heat when hydrogen bonds break and form.
D) fact that water is a poor heat conductor. E) inability of water to dissipate heat into dry air.
(21) At what temperature is water at its densest?
A) 0°C B) 4°C C) 32°C D) 100°C E) 212°C
(22) Why does ice float in liquid water?
A) The liquid water molecules have more kinetic energy and thus support the ice.
B) The ionic bonds between the molecules in ice prevent the ice from sinking.
C) Ice always has air bubbles that keep it afloat.
D) Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid
water.
E) The crystalline lattice of ice causes it to be denser than liquid water.
(23) The following question is based on the diagram below depicting a solute molecule surrounded by a hydration
shell of water.
Based on your knowledge of the polarity of water molecules, the solute molecule is most likely
A) positively charged B) negatively charged C) without charge D) hydrophobic E) nonpolar.
(24) Which of the following ionizes completely in solution and is considered to be a strong base (alkali)?
A) NaCl B) HCl C) NH3 D) H2CO3 E) NaOH
(25) What is the pH of a solution with a hydrogen ion [H+] concentration of 10-8 M?
A) pH 2 B) pH 4 C) pH 6 D) pH 8 E) pH 10
(26) If the pH of a solution is increased from pH 5 to pH 7, it means that the
A) concentration of H+ is twice (2X) what it was at pH 5.
B) concentration of H+ is half (1/2) what it was at pH 5.
C) concentration of OH- is 100 times greater than what it was at pH 5.
D) concentration of OH- is one-hundredth (0.01X) what it was at pH 5.
E) concentration of H+ is 100 times greater and the concentration of OH- is one-hundredth what they were at
pH 5.
(27) One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a
weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+). Thus,
H2CO3 ↔ HCO3- + H+
If the pH of the blood drops, one would expect
A) a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-.
B) the concentration of hydroxide ion (OH-) to increase.
C) the concentration of bicarbonate ion (HCO3-) to increase.
D) the HCO3- to act as a base and remove excess H+ with the formation of H2CO3.
E) the HCO3- to act as an acid and remove excess H+ with the formation of H2CO3.
(28) Pure, freshly-distilled water has a pH of 7. This means that
A) there are no H+ ions in the water. B) there are no OH- ions in the water.
C) the concentration of H+ ions in the water equals the concentration of OH- ions in the water.
D) the concentration of H+ ions in the water is 7 times the concentration of OH- ions in the water.
E) The concentration of OH- ions in the water is 7 times the concentration of H+ ions in the water,
(29) How many electron pairs does carbon share in order to complete its valence shell?
A) 1 B) 2 C) 3 D) 4 E) 8
(30) A carbon atom is most likely to form what kind of bond(s) with other atoms?
A) ionic B) hydrogen C) covalent D) A and B only E) A, B, and C
(31) Which is the best description of a carbonyl group?
A) an oxygen joined to a carbon by a single covalent bond
B) a nitrogen and two hydrogens joined to a carbon by covalent bonds
C) a carbon joined to two hydrogens by single covalent bonds
D) a sulfur and a hydrogen joined to a carbon by covalent bonds
E) a carbon atom joined to an oxygen by a double covalent bond
(32) What is the name of the functional group shown below?
A) carbonyl B) ketone C) aldehyde
D) carboxyl
E) hydroxyl
(33) Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen?
A) an alcohol such as ethanol B) a monosaccharide such as glucose
C) a steroid such as testosterone D) an amino acid such as glycine
E) a hydrocarbon such as benzene
(34) Which two functional groups are always found in amino acids?
A) ketone and aldehyde B) carbonyl and carboxyl
E) hydroxyl and aldehyde
C) carboxyl and amino
D) phosphate and sulfhydryl
(35) Amino acids are acids because they always possess which functional group?
A) amino B) carbonyl C) carboxyl D) sulfhydryl E) aldehyde
(36) Which of the structures below is an impossible covalently bonded molecule?
(37) Which molecule contains a sulfhydryl group?
(38) Which of the following is not a polymer?
A) glucose B) starch C) cellulose D) chitin
E) DNA
(39) What is the chemical mechanism by which cells make polymers from monomers?
A) phosphodiester linkages B) hydrolysis C) dehydration reactions D) ionic bonding of monomers
E) the formation of disulfide bridges between monomers
(40) How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?
A) 12 B) 11 C) 10 D) 9 E) 8
(41) Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
A) Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers.
B) Macromolecular synthesis occurs through the removal of water and digestion occurs through the addition
of water.
C) Dehydration reactions can occur only after hydrolysis.
D) Hydrolysis creates monomers, and dehydration reactions break down polymers.
E) A and B are correct.
(42) On food packages, to what does the term ʺinsoluble fiberʺ refer?
A) cellulose B) polypeptides C) starch D) amylopectin E) chitin
(43) Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose
molecule. How is lactose classified?
A) as a pentose B) as a hexose C) as a monosaccharide D) as a disaccharide E) as a polysaccharide
(44) Which of the following is true of cellulose?
A) It is a polymer composed of sucrose monomers.
B) It is a storage polysaccharide for energy in plant cells.
C) It is a storage polysaccharide for energy in animal cells.
D) It is a major structural component of plant cell walls.
E) It is a major structural component of animal cell plasma membranes.
(45) Humans can digest starch but not cellulose because
A) the monomer of starch is glucose, while the monomer of cellulose is galactose.
B) humans have enzymes that can hydrolyze the beta (β) glycosidic linkages of starch but not the alpha (α)
glycosidic linkages of cellulose.
C) humans have enzymes that can hydrolyze the alpha (α) glycosidic linkages of starch but not the beta (β)
glycosidic linkages of cellulose.
D) humans harbor starch-digesting bacteria in the digestive tract.
E) the monomer of starch is glucose, while the monomer of cellulose is maltose.
(46) All of the following statements concerning saturated fats are true except
A) They are more common in animals than in plants.
B) They have multiple double bonds in the carbon chains of their fatty acids.
C) They generally solidify at room temperature.
D) They contain more hydrogen than saturated fats having the same number of carbon atoms.
(47) A molecule with the formula C18H36O2 is probably a
A) carbohydrate. B) fatty acid. C) protein. D) nucleic acid.
E) hydrocarbon.
(48) Which of the following statements is false for the class of biological molecules known as lipids?
A) They are soluble in water. B) They are an important constituent of cell membranes.
C) They contain more energy than proteins and carbohydrates. D) They are not true polymers.
E) They contain waxes and steroids.
(49) The molecule shown below is
A) polysaccharide.
B) polypeptide.
C) saturated fatty acid.
D) triacylglycerol.
E) unsaturated fatty acid.
(50) Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of
the following is an exception to this statement?
A) a steroid B) cellulose C) DNA D) an enzyme
(51) All of the following contain amino acids except
A) hemoglobin. B) cholesterol. C) antibodies.
E) a contractile protein
D) enzymes.
E) insulin.
(52) There are 20 different amino acids. What makes one amino acid different from another?
A) different carboxyl groups attached to an alpha (α) carbon
B) different amino groups attached to an alpha (α) carbon
C) different side chains (R groups) attached to an alpha (α) carbon
D) different alpha (α) carbons
E) different asymmetric carbons
(53) Which of the following statements is/are true regarding the chemical reaction illustrated below?
A) It is a hydrolysis reaction. B) It results in a peptide bond.
D) A and B only E) A, B, and C
C) It joins two fatty acids together.
(54) At which bond shown on the diagram below, would water need to be added to achieve hydrolysis of the
peptide, back to its component amino acid?
(55) What maintains the secondary structure of a protein?
A) peptide bonds B) hydrogen bonds C) disulfide bonds
D) ionic bonds
E) phosphodiester bonds
(56) The α helix and the β pleated sheet are both common polypeptide forms found in which level of protein
structure?
A) primary B) secondary C) tertiary D) quaternary E) all of the above
(57) Figure below best illustrates the
A) secondary structure of a polypeptide. B) tertiary structure of a polypeptide.
C) quaternary structure of a protein. D) double helix structure of DNA.
E) primary structure of a polysaccharide
(58) A strong covalent bond between amino acids that functions in maintaining a polypeptideʹs specific threedimensional shape is a (an)
A) ionic bond. B) hydrophobic interaction. C) van der Waals interaction. D) disulfide bond.
E) hydrogen bond.
(59) What would be an unexpected consequence of changing one amino acid in a protein consisting of 325 amino
acids?
A) The primary structure of the protein would be changed.
B) The tertiary structure of the protein might be changed.
C) The biological activity or function of the protein might be altered.
D) Only A and C are correct.
E) A, B, and C are correct.
(60) The function of each protein is a consequence of its specific shape. What is the term used for a change in a
proteinʹs three-dimensional shape or conformation due to disruption of hydrogen bonds, disulfide bridges, or
ionic bonds?
A) hydrolysis B) stabilization C) destabilization D) renaturation E) denaturation
(61) The element nitrogen is present in all of the following except
A) proteins. B) nucleic acids. C) amino acids. D) DNA. E) monosaccharides.
(62) Enzymes are
A) carbohydrates.
B) lipids.
C) proteins.
D) nucleic acids.
(63) Which term includes all others in the list?
A) monosaccharide B) disaccharide C) starch
For questions 64-71, use the following diagrams.
D) carbohydrate
E) polysaccharide
(64) Which molecule has hydrophilic and hydrophobic properties and would be found in
plasma membranes?
A) 1 B) 5 C) 6 D) 12 E) 14
(65) Which molecule is glycerol?
A) 1 B) 6 C) 10 D) 14 E) 15
(66) Which molecule is a saturated fatty acid?
A) 1 B) 5 C) 6 D) 8 E) 9
(67) Which of the following molecules act as building blocks (monomers) of polypeptides?
A) 1, 4, and 6 B) 2, 7, and 8 C) 7, 8, and 13 D) 11, 12, and 13 E) 12, 13, and 15
(68) A fat (or triacylglycerol) would be formed as a result of a dehydration reaction between
A) one molecule of 9 and three molecules of 10.
B) three molecules of 9 and one molecule of 10.
C) one molecule of 5 and three molecules of 9.
D) three molecules of 5 and one molecule of 9.
E) one molecule of 5 and three molecules of 10.
(69) Which of the following molecules contains a glycosidic linkage type of covalent bond?
A) 4
B) 6 C) 12
D) 13
E) 15
(70) Which of the following molecules has (have) a functional group that frequently is involved in maintaining the
tertiary structure of a protein?
A) 2 B) 3 C) 9 D) 11 E) 9 and 11
(71) Which of the following molecules consists of a hydrophilic ʺheadʺ region and a hydrophobic ʺtailʺ region?
A) 2 B) 5 C) 7 D) 9 E) 11
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(72) A primary objective of cell fractionation is to
A) view the structure of cell membranes.
B) identify the enzymes outside the organelles.
C) determine the size of various organelles.
D) separate the major organelles so that their particular functions can be determined.
E) crack the cell wall so the cytoplasmic contents can be released.
(73) Which of the following correctly lists the order in which cellular components will be found in the pellet when
homogenized cells are treated with increasingly rapid spins in a centrifuge?
A) ribosomes, nucleus, mitochondria B) chloroplasts, ribosomes, vacuoles
C) nucleus, ribosomes, chloroplasts D) vacuoles, ribosomes, nucleus
E) nucleus, mitochondria, ribosomes
(74) All of the following are part of a prokaryotic cell except
A) DNA. B) a cell wall. C) a plasma membrane. D) ribosomes.
E) an endoplasmic reticulum.
(75) Which of the following is a major cause of the size limits for certain types of cells?
A) the evolution of larger cells after the evolution of smaller cells
B) the difference in plasma membranes between prokaryotes and eukaryotes
C) the evolution of eukaryotes after the evolution of prokaryotes
D) the need for a surface area of sufficient area to allow the cellʹs function
E) the observation that longer cells usually have greater cell volume
(76) Large numbers of ribosomes are present in cells that specialize in producing which of the following
molecules?
A) lipids B) starches C) proteins D) steroids E) glucose
(77) Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?
A) ribosome B) lysosome C) smooth endoplasmic reticulum D) mitochondrion E) contractile vacuole
(78) Which structure is the last site of proteins that may be exported from the cell?
A) rough ER B) lysosomes C) plasmodesmata D) Golgi vesicles E) tight junctions
(79) Tay-Sachs disease is a human genetic abnormality that results in cells of the brain accumulating complex
lipids that would normally be broken down. Which cellular organelle must be involved in this condition?
A) the endoplasmic reticulum B) the Golgi apparatus C) the lysosome D) mitochondria
E) membrane-bound ribosomes
(80) The liver is involved in detoxification of many poisons and drugs. Which of the following
structures is primarily involved in this process and therefore abundant in liver cells?
A) rough ER B) smooth ER C) Golgi apparatus D) Nuclear envelope E) Transport vesicles
(81) Which of the following is a compartment that often takes up much of the volume of a plant cell?
A) lysosome
B) vacuole
C) mitochondrion
D) Golgi apparatus
E) peroxisome
(82) Which of the following contains its own DNA and ribosomes?
A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus
E) peroxisome
(83) Which of the following relationships between cell structures and their respective functions is correct?
A) cell wall: support, protection B) chloroplasts: chief sites of cellular respiration
C) chromosomes: cytoskeleton of the nucleus D) ribosomes: secretion
E) lysosomes: formation of ATP
(84) Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?
A) peroxisomes B) desmosomes C) gap junctions D) extracellular matrix E) tight junctions
(85) Which of the following types of molecules are the major structural components of the cell membrane?
A) phospholipids and cellulose B) nucleic acids and proteins C) phospholipids and proteins
D) proteins and cellulose E) glycoproteins and cholesterol
Questions 86-90 refer to the diagram of the cell membrane below.
(86) protein (87) cholesterol (88) microfilament of the cytoskeleton (89) glycolipid
(90) fiber of the extracellular matrix
(91) The presence of cholesterol in the plasma membranes of some animals
A) enables the membrane to stay fluid more easily when cell temperature drops.
B) enables the animal to remove hydrogen atoms from saturated phospholipids.
C) enables the animal to add hydrogen atoms to unsaturated phospholipids.
D) makes the membrane less flexible, allowing it to sustain greater pressure from within the cell.
E) makes the animal more susceptible to circulatory disorders.
(92) Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane
more fluid at lower temperatures?
A) The double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart.
B) Unsaturated fatty acids have a higher cholesterol content and therefore more cholesterol in membranes.
C) Unsaturated fatty acids permit more water in the interior of the membrane.
D) The double bonds block interaction among the hydrophilic head groups of the lipids.
E) The double bonds result in shorter fatty acid tails and thinner membranes.
(93) Of the following functions, which is most important for the glycoproteins and glycolipids of animal cell
membranes?
A) facilitated diffusion of molecules down their concentration gradients
B) active transport of molecules against their concentration gradients
C) maintaining the integrity of a fluid mosaic membrane
D) maintaining membrane fluidity at low temperatures
E) a cellʹs ability to distinguish one type of neighboring cell from another
(94) What kinds of molecules pass through a cell membrane most easily?
A) large and hydrophobic B) small and hydrophobic C) large polar
E) monosaccharides such as glucose
D) ionic
(95) Which of the following statements is correct about diffusion?
A) It is very rapid over long distances.
B) It requires an expenditure of energy by the cell.
C) It is a passive process in which molecules move from a region of higher concentration to a region of lower
concentration.
D) It is an active process in which molecules move from a region of lower concentration to one of higher
concentration.
E) It requires integral proteins in the cell membrane.
(96) Water passes quickly through cell membranes because
A) the bilayer is hydrophilic. B) it moves through hydrophobic channels.
C) water movement is tied to ATP hydrolysis. D) it is a small, polar, charged molecule.
E) it moves through aquaporins in the membrane.
(97) A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled
water, equal to the volume of blood lost, is transferred directly into one of his veins. What will be the most
probable result of this transfusion?
A) It will have no unfavorable effect as long as the water is free of viruses and bacteria.
B) The patientʹs red blood cells will shrivel up because the blood fluid is hypotonic compared to the cells.
C) The patientʹs red blood cells will swell because the blood fluid is hypotonic compared to the cells.
D) The patientʹs red blood cells will shrivel up because the blood fluid is hypertonic compared to the cells.
E) The patientʹs red blood cells will burst because the blood fluid is hypertonic compared to the cells.
Use the following information to answer questions 98-99.
The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose
but not to sucrose. Side A is half filled with a solution of 2 M sucrose and 1 M glucose. Side B is half filled with 1
M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal.
(98) Initially, in terms of tonicity, the solution in side A with respect to that in side B is
A) hypotonic. B) plasmolyzed. C) isotonic. D) saturated. E) hypertonic.
(99) After the system reaches equilibrium, what changes are observed?
A) The molarity of sucrose and glucose are equal on both sides.
B) The molarity of glucose is higher in side A than in side B.
C) The water level is higher in side A than in side B.
D) The water level is unchanged.
E) The water level is higher in side B than in side A.
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(100) The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable
membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution
of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M
glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same.
At the beginning of the experiment,
A) side A is hypertonic to side B. B) side A is hypotonic to side B.
D) side A is hypertonic to side B with respect to glucose.
E) side A is hypotonic to side B with respect to sodium chloride
C) side A is isotonic to side B.
(101) Celery stalks that are immersed in fresh water for several hours become stiff. Similar stalks left in a salt
solution become limp. From this we can deduce that the cells of the celery stalks are
A) hypotonic to both fresh water and the salt solution.
B) hypertonic to both fresh water and the salt solution.
C) hypertonic to fresh water but hypotonic to the salt solution.
D) hypotonic to fresh water but hypertonic to the salt solution.
E) isotonic with fresh water but hypotonic to the salt solution
Use the following information to answer questions 102-104.
Five dialysis bags, constructed from a semi-permeable membrane that is impermeable to sucrose, were filled with
various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M
sucrose solution. At 10-minute intervals, the bags were massed (weighed) and the percent change in mass of each
bag was graphed.
(102) Which line represents the bag that contained a solution isotonic to the 0.6 molar solution at the beginning of
the experiment?
(103) Which line represents the bag with the highest initial concentration of sucrose?
(104) Which line or lines represent(s) bags that contain a solution that is hypertonic at the end of 60 minutes?
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(105) When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely
to occur?
A) the cell will burst B) the cell membrane will lyse C) plasmolysis will shrink the interior
D) the cell will become flaccid E) the cell will become turgid
(106) Which of the following membrane activities require energy from ATP hydrolysis?
A) facilitated diffusion. B) movement of water into a cell C) Na+ ions moving out of the cell
D) movement of glucose molecules E) movement of water into a paramecium
(107) Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine,
however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor
cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal
cells?
A) simple diffusion B) phagocytosis C) active transport pumps D) exocytosis E) facilitated diffusion
(108) An organism with a cell wall would have the most difficulty doing which process?
A) diffusion B) osmosis C) active transport D) phagocytosis E) facilitated diffusion
(109) Which term most precisely describes the cellular process of breaking down large molecules into smaller
ones?
A) catalysis B) metabolism C) anabolism D) dehydration E) catabolism
(110) Which of the following is a statement of the first law of thermodynamics?
A) Energy cannot be created or destroyed.
B) The entropy of the universe is decreasing.
C) The entropy of the universe is constant.
D) Kinetic energy is stored energy that results from the specific arrangement of matter.
E) Energy cannot be transferred or transformed.
(111) Which of the following statements is representative of the second law of thermodynamics?
A) Conversion of energy from one form to another is always accompanied by some gain of free energy.
B) Heat represents a form of energy that can be used by most organisms to do work.
C) Without an input of energy, organisms would tend toward decreasing entropy.
D) Cells require a constant input of energy to maintain their high level of organization.
E) Every energy transformation by a cell decreases the entropy of the universe.
(112) The mathematical expression for the change in free energy of a system is △G = △H- T△S.
Which of the following is (are) correct?
A) △S is the change in enthalpy, a measure of randomness.
B) △H is the change in entropy, the energy available to do work.
C) △G is the change in free energy.
D) T is the temperature in degrees Celsius.
(113) A chemical reaction that has a positive △G is correctly described as
A) endergonic. B) endothermic. C) enthalpic. D) spontaneous. E) exothermic.
(114) What term is used to describe the transfer of free energy from catabolic pathways to anabolic pathways?
A) feedback regulation B) bioenergetics C) energy coupling D) entropy E) cooperativity
(115) When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?
A) It is used to power yet more cellular work. B) It is used to store energy as more ATP.
C) It is used to generate ADP from nucleotide precursors. D) It is lost to the environment.
E) It is transported to specific organs such as the brain.
(116) Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose
by the enzyme sucrase results in
A) bringing glucose and fructose together to form sucrose.
B) the release of water from sucrose as the bond between glucose and fructose is broken.
C) breaking the bond between glucose and fructose and forming new bonds from the atoms of water.
D) production of water from the sugar as bonds are broken between the glucose monomers.
(117) Reactants capable of interacting to form products in a chemical reaction must first overcome a
thermodynamic barrier known as the reactionʹs
A) entropy. B) activation energy. C) endothermic level. D) heat content. E) free-energy content.
(118) According to the induced fit hypothesis of enzyme catalysis, which of the following is correct?
A) The binding of the substrate depends on the shape of the active site.
B) Some enzymes change their structure when activators bind to the enzyme.
C) A competitive inhibitor can outcompete the substrate for the active site.
D) The binding of the substrate changes the shape of the enzymeʹs active site.
E) The active site creates a microenvironment ideal for the reaction.
Use the following graphs to answer questions 119-120.
(119) Which curve represents the behavior of an enzyme taken from a bacterium that lives in hot springs at
temperatures of 70°C or higher?
A) curve 1 B) curve 2 C) curve 3 D) curve 4 E) curve 5
(120) Which curve was most likely generated from analysis of an enzyme from a human stomach where conditions
are strongly acid?
A) curve 1 B) curve 2 C) curve 3 D) curve 4 E) curve 5
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(121) When you have a severe fever, what may be a grave consequence if this is not controlled?
A) destruction of your enzymesʹ primary structure B) removal of amine groups from your proteins
C) change in the folding of enzymes D) removal of the amino acids in active sites
E) binding of enzymes to inappropriate substrates
Use the following diagram to answer questions 122-129.
(122) Which of the following terms best describes the reaction?
A) endergonic B) exergonic C) anabolic D) allosteric
E) nonspontaneous
(123) Which of the following represents the △G of the reaction?
A) a B) b C) c D) d E) e
(124) Which of the following would be the same in an enzyme-catalyzed or noncatalyzed reaction?
A) a B) b C) c D) d E) e
(125) Which of the following bests describes the reaction?
A) negative △G, spontaneous B) positive △G, nonspontaneous C) positive △G, exergonic
D) negative △G, endergonic E) △G of zero, chemical equilibrium
(126) Which of the following represents the difference between the free-energy content of the reaction and the
free-energy content of the products?
A) a B) b C) c D) d E) e
(127) Which of the following represents the activation energy required for the enzyme-catalyzed reaction?
A) a B) b C) c D) d E) e
(128) Which of the following represents the activation energy required for a noncatalyzed reaction?
A) a B) b C) c D) d E) e
(129) Which best describes the reaction?
A) The amount of free energy initially present in the reactants is indicated by ʺa.ʺ
B) The amount of free energy present in the products is indicated by ʺe.ʺ
C) The amount of free energy released as a result of the noncatalyzed reaction is indicated by ʺc.ʺ
D) The amount of free energy released as a result of the catalyzed reaction is indicated by ʺd.ʺ
E) The difference between ʺbʺ and ʺcʺ is the activation energy added by the presence of the enzyme.