tb ap bio 2-3 (first test)
41) Which is a hydroxyl functional group?
A) -OH
26) A small birthday candle is weighed, then lighted and placed beneath a metal can containing 100 mL of water. Careful records are kept as the temperature of the water rises. Data from this experiment are shown on the graph. What amount of heat energy is released in the burning of candle wax?
A) 0.5 kilocalories per gram of wax burned
48) Assume that acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydroxyl ion concentration of this lake?
A) 1 × 10^-10 mol of hydroxyl ion per liter of lake water
98) Which of the following molecules has (have) a functional group that frequently is involved in maintaining the tertiary structure of a protein?
A) 2
29) The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water?
A) 55.6M
53) Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O → H2CO3. Carbonic acid (H2CO3) is a weak acid. Respiring cells release CO2. What prediction can we make about the pH of blood as that blood first comes in contact with respiring cells?
A) Blood pH will decrease slightly.
68) Which of the following best describes the flow of information in eukaryotic cells?
A) DNA → RNA → proteins
22) Research indicates that Albuterol, a drug used to relax bronchial muscles, improving airflow and thus offering relief from asthma, consists only of one enantiomer, the R-form. Why is it important for this drug to consist of only one enantiomeric form, rather than a mixture of enantiomers?
A) Different enantiomers may have different or opposite physiological effects.
4) For this pair of items, choose the option that best describes their relationship. (A) The probability that amino acids with nonpolar side chains are hydrophobic. (B) The probability that amino acids with side chains containing a carboxyl group are hydrophobic.
A) Item (A) is greater than item (B).
5) For this pair of items, choose the option that best describes their relationship. (A) The number of purines in the DNA strand 5ʹ-AAGAGGAGAAA-3ʹ (B) The number of pyrimidines in the DNA strand 5ʹ-AAGAGGAGAAA-3ʹ
A) Item (A) is greater than item (B).
4) One of the following people set up a closed system to mimic Earthʹs early atmosphere and discharged electrical sparks through it. A variety of organic compounds common in organisms were formed. Who did this?
A) Stanley Miller
5) Which of the following people used this apparatus to study formation of organic compounds?
A) Stanley Miller
19) Which of the following is true of both starch and cellulose?
A) They are both polymers of glucose.
24) Which of the following statements is false for the class of biological molecules known as lipids?
A) They are soluble in water.
19) Which of the following statements correctly describes geometric isomers?
A) They have variations in arrangement around a double bond.
61) Roger Kornberg used this method for elucidating the structure of RNA polymerase.
A) X-ray crystallography
47) One of the buffers that contribute to pH stability in human blood is carbonic acid H2CO3. Carbonic acid is a weak acid that when placed in an aqueous solution dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+). Thus, H2CO3 ↔ HCO3- + H+ If the pH of the blood increases, one would expect
A) a decrease in the concentration of H2CO3 and an increase in the concentration of H2O.
30) 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
13) On food packages, to what does the term ʺinsoluble fiberʺ refer?
A) cellulose
38) Which of the following solutions has the greatest concentration of hydrogen ions [H +]?
A) gastric juice at pH 2
6) Which of the following is not a polymer?
A) glucose
12) The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the α form. Which of the following could amylase break down?
A) glycogen
18) All of the following are polysaccharides except
A) glycogen
15) If 2 molecules of the general type shown in Figure 5.1 were linked together, carbon 1 of one molecule to carbon 4 of the other, the single molecule that would result would be
A) maltose.
16) Hydrophobic substances such as vegetable oil are
A) nonpolar substances that repel water molecules.
36) What is the pH of a solution with a hydroxyl ion [OH-] concentration of 10-12 M?
A) pH 2
47) Which bonds are created during the formation of the primary structure of a protein?
A) peptide bonds
15) Based on your knowledge of the polarity of water molecules, the solute molecule is most likely
A) positively charged.
38) The bonding of two amino acid molecules to form a larger molecule requires which of the following?
A) removal of a water molecule
48) Which molecule is water soluble because it has a hydroxyl functional group?
A) row one: two H's; row two: H-C-C-OH; row three: two H's
49) Which molecule is an alcohol?
A) row one: two H's; row two: H-C-C-OH; row three: two H's
52) Figure 5.7 best illustrates the
A) secondary structure of a polypeptide.
57) Which molecule contains an amino functional group, but is not an amino acid?
A) the one with the NH2 connected
60) Which molecule can function as a base?
A) the one with the NH2 connected
35) The bonding of two amino acid molecules to form a larger molecule requires
A) the release of a water molecule.
44) Which bond is closest to the N-terminus of the molecule?
A- between the very left n and the first c from the left
73) A double-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines. This DNA molecule could be composed of
B) 120 thymine and 120 adenine molecules.
15) How many structural isomers are possible for a substance having the molecular formula C4H10?
B) 2
91) Which of the following molecules act as building blocks (monomers) of polypeptides?
B) 2, 7, and 8
24) How many grams of the molecule in Figure 3.2 would be required to make 1 L of a 0.5 M solution of the molecule?(Carbon = 12, Oxygen = 16, Hydrogen = 1)
B) 30
77) If one strand of a DNA molecule has the sequence of bases 5ʹATTGCA3ʹ, the other complementary strand would have the sequence
B) 3ʹTAACGT5ʹ.
13) At what temperature is water at its densest?
B) 4°C
99) Which of the following molecules consists of a hydrophilic ʺheadʺ region and a hydrophobic ʺtailʺ region?
B) 5
85) Which molecule has hydrophilic and hydrophobic properties and would be found in plasma membranes?
B) 5- the longest one
6) Which of the following effects is produced by the high surface tension of water?
B) A water strider can walk across the surface of a small pond.
56) The R group or side chain of the amino acid serine is —CH2-OH. The R group or side chain of the amino acid alanine is —CH3. Where would you expect to find these amino acids in a globular protein in aqueous solution?
B) Alanine would be in the interior, and serine would be on the exterior of the globular protein.
50) Which molecules contain a carbonyl group?
B) B and C B: plus sign w C in the center and right and H at the top, left, bottom, double bonded O to the right C and H to the right C C: row one; H, O, H; row two: H-C-C-C-H (middle c double bonded to O in row one); row three: two H's
11) The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?
B) C18H30O15
22) The molecular mass of glucose (C6H12O6) is 180 g. Which of the following procedures should you carry out to make a 0.5 M solution of glucose?
B) Dissolve 90 g of glucose in a small volume of water, and then add more water until the total volume of the solution is 1 L.
31) Which of the following ionizes completely in solution and is considered to be a strong acid?
B) HCl
37) Which of the following statements is/are true regarding the chemical reaction illustrated in Figure 5.5?
B) It results in a peptide bond.
28) A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound?
B) It should dissolve in water.
1) For this pair of items, choose the option that best describes their relationship. (A) The number of alpha glucose 1-4 linkages in cellulose (B) The number of alpha glucose 1-4 linkages in starch
B) Item (A) is less than item (B).
3) For this pair of items, choose the option that best describes their relationship. (A) The number of cis double bonds in saturated fatty acids (B) The number of cis double bonds in unsaturated fatty acids
B) Item (A) is less than item (B).
10) One of the following people was the first to suggest that organic compounds, those found in living organisms, were distinctly different from inorganic compounds found in the nonliving world. Though this suggestion is now known to be incorrect, it stimulated important research into organic compounds. Who suggested this?
B) Jakob Berzelius
7) Which of the following takes place as an ice cube cools a drink?
B) Kinetic energy in the drink decreases.
66) Which of the following statements about the 5ʹ end of a polynucleotide strand of DNA is correct?
B) The 5ʹ end has a phosphate group attached to the number 5 carbon of ribose.
14) Why are hydrocarbons insoluble in water?
B) The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
65) DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNAase?
B) The phosphodiester bonds between deoxyribose sugars would be broken.
33) Why are human sex hormones considered to be lipids?
B) They are steroids, which are not soluble in water.
22) All of the following statements concerning saturated fats are true except
B) They have multiple double bonds in the carbon chains of their fatty acids.
2) 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?
B) a hydrogen bond
25) What is a triacylglycerol?
B) a lipid made with three fatty acids and glycerol
21) Research indicates that Ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that
B) are mirror images of one another.
27) Thalidomide and L-dopa, shown below, are examples of pharmaceutical drugs that occur as enantiomers, or molecules that
B) are mirror images of one another.
39) Polysaccharides, lipids, and proteins are similar in that they
B) are synthesized from monomers by dehydration reactions.
62) Which of the following uses the amino acid sequences of polypeptides to predict a proteinʹs three-dimensional structure?
B) bioinformatics
64) What is the term used for a protein molecule that assists in the proper folding of other proteins?
B) chaperonin
34) All of the following contain amino acids except
B) cholesterol.
78) What is the structural feature that allows DNA to replicate?
B) complementary pairing of the nitrogenous bases
70) Which of the following are nitrogenous bases of the pyrimidine type?
B) cytosine and uracil
23) A molecule with the formula C18H36O2 is probably a
B) fatty acid.
67) Of the following functions, the major purpose of RNA is to
B) function in the synthesis of protein.
71) Which of the following are nitrogenous bases of the purine type?
B) guanine and adenine
48) What maintains the secondary structure of a protein?
B) hydrogen bonds
79) A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism
B) is more closely related to frogs than to humans.
26) Three or four of the pairs of structures shown below depict enantiomers (enantiomeric forms) of the same molecule. Which pair, if any, are NOT enantiomers of a single molecule? If each of the pairs depicts enantiomers, choose answer F.
B) left triangle: CO2H top, H left, CH3 bottom, CH3 right. right triangleL COSH top, H3C left, CH3 bottom, H right
82) Which of the following is a diverse group of hydrophobic molecules?
B) lipids
52) Which molecule has a carbonyl functional group in the form of an aldehyde?
B) plus sign w C in the center and right and H at the top, left, bottom, double bonded O to the right C and H to the right C
50) The α helix and the β pleated sheet are both common polypeptide forms found in which level of protein structure?
B) secondary
3) An example of a hydrogen bond is the bond between
B) the H of one water molecule and the O of another water molecule.
55) Which molecule contains a sulfhydryl functional group?
B) the one with -SH connected
58) Which molecule is a thiol?
B) the one with -SH connected
94) A fat (or triacylglycerol) would be formed as a result of a dehydration reaction between
B) three molecules of 9 and one molecule of 10.
2) Early 19th-century scientists believed that living organisms differed from nonliving things as a result of possessing a ʺlife forceʺ that could create organic molecules from inorganic matter. The term given to this belief is
B) vitalism.
27) Identical heat lamps are arranged to shine on identical containers of water and methanol (wood alcohol), so that each liquid absorbs the same amount of energy minute by minute. The covalent bonds of methanol molecules are non-polar, so there are no hydrogen bonds among methanol molecules. Which of the following graphs correctly describes what will happen to the temperature of the water and the methanol?
B- both lines go upwards but the methanol (dotted) line is steeper
8) How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?
C) 10
88) Which molecule is glycerol?
C) 10
55) Equal volumes of vinegar from a freshly-opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will have the highest pH?
C) 100 mL of household cleanser containing 0.5M ammonia
20) When an ionic compound such as sodium chloride (NaCl) is placed in water the component atoms of the NaCl crystal dissociate into individual sodium ions (Na+) and chloride ions (Cl-). In contrast, the atoms of covalently bonded molecules (e.g., glucose, sucrose, glycerol) do not generally dissociate when placed in aqueous solution. Which of the following solutions would be expected to contain the greatest number of particles (molecules or ions)?
C) 1Lof1.0 MNaCl
72) If a DNA sample were composed of 10% thymine, what would be the percentage of guanine?
C) 40
28) You have a freshly-prepared 0.1M solution of glucose in water. Each liter of this solution contains how many glucose molecules?
C) 6.02 × 10^24
30) You have a freshly-prepared 1M solution of glucose in water. You carefully pour out a 100 mL sample of that solution. How many glucose molecules are included in that 100 mL sample?
C) 6.02 × 10^24
23) How many grams of the molecule in Figure 3.2 would be equal to 1 mol of the molecule? (Carbon = 12, Oxygen = 16, Hydrogen = 1)
C) 60
92) Which of the following molecules is an amino acid with a hydrophobic R group or side chain?
C) 7
57) You have two beakers. One contains a solution of HCl at pH = 1.0. The other contains a solution of NaOH at pH = 13. Into a third beaker, you slowly and cautiously pour 20 mL of the HCL and 20 mL of the NaOH. After complete stirring, the pH of the mixture will be
C) 7.0.
93) Which of the following molecules could be joined together by a peptide bond as a result of a dehydration reaction?
C) 7and8
41) Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein?
C) 99
75) Which of the following statements best summarizes the structural differences between DNA and RNA?
C) DNA nucleotides contain a different sugar than RNA nucleotides.
6) Which of the following people was the first to synthesize an organic compound, urea, from inorganic starting materials?
C) Friedrich Wohler
7) Which of the following peopleʹs synthesis of this compound from inorganic starting materials provided evidence against vitalism?
C) Friedrich Wohler
2) For this pair of items, choose the option that best describes their relationship. (A) The probability of finding chitin in fungal cell walls (B) The probability of finding chitin in arthropod exoskeletons
C) Item (A) is exactly or very approximately equal to item (B).
28) Which of the following statements is true regarding the molecule illustrated in Figure 5.3?
C) Molecules of this type are usually liquid at room temperature.
56) You have two beakers; one contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen.
C) NaCl crystals will dissolve readily in water but will not dissolve in methanol.
62) Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other?
C) Testosterone and estradiol have different functional groups attached to the same carbon skeleton.
26) Which of the following is true regarding saturated fatty acids?
C) They are the principal molecules in lard and butter.
69) Which of the following descriptions best fits the class of molecules known as nucleotides?
C) a nitrogenous base, a phosphate group, and a pentose sugar
10) Waterʹs high specific heat is mainly a consequence of the
C) absorption and release of heat when hydrogen bonds break and form.
34) A given solution contains 0.0001(10-4) moles of hydrogen ions [H+] per liter. Which of the following best describes this solution?
C) acidic: H+ donor
60) What method did Frederick Sanger use to elucidate the structure of insulin?
C) analysis of amino acid sequence of small fragments
17) Shown here in Figure 4.2 are the structures of glucose and fructose. These two molecules differ in the
C) arrangement of carbon, hydrogen, and oxygen atoms.
1) Organic chemistry is a science based on the study of
C) carbon compounds.
34) Amino acids are acids because they always possess which functional group?
C) carboxyl
33) Which two functional groups are always found in amino acids?
C) carboxyl and amino
37) Which functional groups can act as acids?
C) carboxyl and phosphate
41) If the pH of a solution is increased from pH 5 to pH 7, it means that the
C) concentration of OH- is 100 times greater than what it was at pH 5.
12) A carbon atom is most likely to form what kind of bond(s) with other atoms?
C) covalent
7) What is the chemical mechanism by which cells make polymers from monomers?
C) dehydration reactions
36) There are 20 different amino acids. What makes one amino acid different from another?
C) different side chains (R groups) attached to an alpha (α) carbon
21) Humans can digest starch but not cellulose because
C) humans have enzymes that can hydrolyze the alpha (α) glycosidic linkages of starch but not the beta (β) glycosidic linkages of cellulose.
25) Which of the pairs of molecular structures shown below do NOT depict enantiomers (enantiomeric forms) of the same molecule?
C) left triangle: CO2H at the top, H at the left, H at the bottom, NH2 right. right triangle: CO2H top, H2N left, H bottom, H right
38) Which of the structures is an impossible covalently bonded molecule?
C) looks like a cross with an extra H in the middle. 5 H's, 2 C's, one O double-bonded to the rightmost C
45) Which is a carboxyl functional group?
C) looks like an L; O double bonded to -c-o-h
46) Which is an acidic functional group that can dissociate and release H+ into a solution?
C) looks like an L; O double bonded to -c-o-h
1) In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
C) polar covalent bonds.
84) Enzymes are
C) proteins.
51) Which molecule has a carbonyl functional group in the form of a ketone?
C) row one; H, O, H; row two: H-C-C-C-H (middle c double bonded to O in row one); row three: two H's
23) Three or four of the following illustrations depict different structural isomers of the organic compound with molecular formula C6H14. For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted. Which one, if any, is NOT a structural isomer of this compound?C)
C) six c's in total, two rows, top row has four (two in the middle double bonded) and bottom row has two. only answer w double bond
32) What is the structure shown in Figure 5.4?
C) steroid molecule
16) The two molecules shown in Figure 4.1 are best described as
C) structural isomers.
55) At which level of protein structure are interactions between the side chains (R groups) most important?
C) tertiary
4) Water is able to form hydrogen bonds because
C) the bonds that hold together the atoms in a water molecule are polar covalent bonds.
51) Pure, freshly-distilled water has a pH of 7. This means that
C) the concentration of H+ ions in the water equals the concentration of OH- ions in the water.
12) Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon?
C) the release of heat by the formation of hydrogen bonds
53) The tertiary structure of a protein is the
C) unique three-dimensional shape of the fully folded polypeptide.
43) Which bond is a peptide bond?
C- between second c from the left and the N in the middle
42) At which bond would water need to be added to achieve hydrolysis of the peptide, back to its component amino acid?
C- between third c from the left and the N in the middle
52) Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O → H2CO3. Carbonic acid (H2CO3) is a weak acid. If CO2 is bubbled into a beaker containing pure, freshly-distilled water, which of the following graphs correctly describes the results?
C- slightly curved line going up
42) Which is an amino functional group?
D) -NH2
47) Which is a basic functional group that can accept H+ and become positively charged?
D) -NH2
42) One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 L of a solution of pH 6?
D) 10,000 times more
9) The nutritional information on a cereal box shows that one serving of a dry cereal has 200 kilocalories. If one were to burn one serving of the cereal, the amount of heat given off would be sufficient to raise the temperature of 20 kg of water how many degrees Celsius?
D) 10.0°C
95) Which of the following molecules could be joined together by a phosphodiester type of covalent bond?
D) 11 and 12
86) Which of the following combinations could be linked together to form a nucleotide?
D) 11, 12, and 13
96) Which of the following molecules is the pentose sugar found in RNA?
D) 12
25) How many grams of the molecule in Figure 3.2 would be required to make 2.5 L of a 1 M solution of the molecule?(Carbon = 12, Oxygen = 16, Hydrogen = 1)
D) 150
11) How many electron pairs does carbon share in order to complete its valence shell?
D) 4
57) Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded proteins?
D) A and B only A) Alzheimerʹs B) Parkinsonʹs
27) Which of the following statements is true regarding the molecule illustrated in Figure 5.2?
D) A and B only A) It is a saturated fatty acid. B) A diet rich in this molecule may contribute to atherosclerosis.
8) Which of the following people synthesized an organic compound, acetic acid, from inorganic substances that had been prepared directly from pure elements?
D) Hermann Kolbe
9) Which of the following peopleʹs synthesis of this compound from inorganic starting materials provided evidence against vitalism?
D) Hermann Kolbe
14) Why does ice float in liquid water?
D) Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.
20) Which of the following is true of cellulose?
D) It is a major structural component of plant cell walls.
33) Which of the following statements is completely correct?
D) NH3 is a weak base (alkali), and HCl is a strong acid.
32) Which of the following is a false statement concerning amino groups?
D) They are nonpolar.
44) Which of the following statements is true about buffer solutions?
D) They maintain a relatively constant pH when either acids or bases are added to them.
36) A chemist wishes to make an organic molecule less acidic. Which of the following functional groups should be added to the molecule in order to do so?
D) amino
31) Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen?
D) an amino acid such as glycine
17) Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?
D) as a disaccharide
30) What is the name of the functional group shown in Figure 4.4?
D) carboxyl
10) Which of the following polymers contain nitrogen?
D) chitin
54) A strong covalent bond between amino acids that functions in maintaining a polypeptideʹs specific three-dimensional shape is a (an)
D) disulfide bond.
11) Which type of bond must be broken for water to vaporize?
D) hydrogen bonds
49) Which type of interaction stabilizes the alpha (α) helix and the beta (β) pleated sheet structures of proteins?
D) hydrogen bonds
5) What gives rise to the cohesiveness of water molecules?
D) hydrogen bonds
24) Which of the pairs of molecular structures shown below depict enantiomers (enantiomeric forms) of the same molecule?
D) left triangle: CO2H at the top, H2N bottom left, H at bottom point, CH3 right. right triangle: CO2H at the top, H3C at the left, H bottom, NH2 right
83) Which of the following store and transmit hereditary information?
D) nucleic acids
37) What is the pH of a solution with a hydrogen ion [H+] concentration of 10-8 M?
D) pH 8
53) Which molecule contains a carboxyl group?
D) plus sign w C in the center, H in the top left and bottom, N on the right connected to two H's
54) Which molecule can increase the concentration of hydrogen ions in a solution and is therefore an organic acid?
D) plus sign w C in the center, H in the top left and bottom, N on the right connected to two H's
18) Shown here in Figure 4.2 are the structures of glucose and fructose. These two molecules are
D) structural isomers.
46) 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
D) the HCO3- to act as a base and remove excess H+ with the formation of H2CO3.
8) Which of the following statements correctly defines a kilocalorie?
D) the amount of heat required to raise the temperature of 1 kg of water by 1°C
56) Which molecule functions to transfer energy between organic molecules?
D) the one with the P
59) Which molecule is an organic phosphate?
D) the one with the P
80) Which of the following is an example of hydrolysis?
D) the reaction of a fat, forming glycerol and fatty acids with the utilization of water
49) Research indicates that acid precipitation can damage living organisms by
D) washing away certain mineral ions that help buffer soil solution and are essential nutrients for plant growth.
35) A carbon skeleton is covalently bonded to both an amino group and a carboxyl group. When placed in water it
D) would function as both an acid and a base.
51) The structure depicted in Figure 5.7 shows the
D) α helix secondary structure of a polypeptide.
44) Which is a functional group that helps stabilize proteins by forming covalent cross-links within or between protein molecules?
E) -SH
87) Which of the following molecules contain(s) an aldehyde type of carbonyl functional group?
E) 1 and 4
43) One liter of a solution pH 9 has how many more hydroxyl ions (OH -) than 1 L of a solution of pH 4?
E) 100,000 times more
90) Which of the following molecules is a purine type of nitrogenous base?
E) 13
100) Which of the following statements is false?
E) 14 and 15 could be joined together to form a polypeptide.
97) Which of the following molecules contains a glycosidic linkage type of covalent bond?
E) 15
46) How many different kinds of polypeptides, each composed of 12 amino acids, could be synthesized using the 20 common amino acids?
E) 20^12
18) How many molecules of glucose (C6H2O6 molecular mass =180 daltons) would be present in one mole of glucose?
E) 6.02 × 10^23
19) How many molecules of glycerol (C3H8O3) would be present in 1 L of a 1 M glycerol solution?
E) 6.02 × 10^23
89) Which molecule is a saturated fatty acid?
E) 9
9) Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
E) A and B are correct. 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.
16) Which of the following descriptors is true of the molecule shown in Figure 5.1?
E) A and C only A) hexose C) glucose
17) One mole (mol) of a substance is
E) A and D only A) 6.02 × 1023 molecules of the substance. D) the molecular mass of the substance expressed in grams.
31) The hydrogenation of vegetable oil results in which of the following?
E) A, B, and C A) saturated fats and unsaturated fats with trans double bonds B) an increased contribution to artherosclerosis C) the oil (fat) being a solid at room temperature
40) Dehydration reactions are used in forming which of the following compounds?
E) A, B, and C A) triacylglycerides B) polysaccharides C) proteins
58) What would be an unexpected consequence of changing one amino acid in a protein consisting of 325 amino acids?
E) A, B, and C are correct. 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.
13) Which of the following statements best describes the carbon atoms present in all organic molecules?
E) A, B, and C are correct. A) They were incorporated into organic molecules by plants. B) They were processed into sugars through photosynthesis. C) They are ultimately derived from carbon dioxide.
14) A molecule with the chemical formula C6H12O6 is probably a
E) A, B, and C. A) carbohydrate. B) lipid. C) monosaccharide
40) If the pH of a solution is decreased from 9 to 8, it means that the
E) Both B and D are correct. B) concentration of H+ has increased 10-fold (10X) compared to what it was at pH 9. D) concentration of OH- has decreased to one-tenth (1/10) what it was at pH 9.
45) Buffers are substances that help resist shifts in pH by
E) Both B and D are correct. B) donating H+ to a solution when they have been depleted. D) accepting H+ when the are in excess.
21) The molecular mass of glucose is 180 g. Which of the following procedures should you carry out to make a 1 M solution of glucose?
E) Dissolve 180 g of glucose in water, and then add more water until the total volume of the solution is 1 L.
32) Which of the following ionizes completely in solution and is considered to be a strong base (alkali)?
E) NaOH
50) Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that
E) None of the other answer choices correctly describes these solutions.
54) A 100 mL beaker contains 10 mL of NaOH solution at pH = 13. A technician carefully pours into the beaker, 10 mL of HCl at pH = 1. Which of the following statements correctly describes the results of this mixing?
E) The pH of the beakerʹs contents falls.
29) Which is the best description of a carbonyl group?
E) a carbon atom joined to an oxygen by a double covalent bond
59) Altering which of the following levels of structural organization could change the function of a protein?
E) all of the above
74) The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA
E) contains one less oxygen atom.
63) 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?
E) denaturation
20) The two molecules shown in Figure 4.3 are best described as
E) geometric isomers.
76) In the double helix structure of nucleic acids, cytosine hydrogen bonds to
E) guanine.
3) The experimental approach taken in current biological investigations presumes that
E) living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena.
81) The element nitrogen is present in all of the following except
E) monosaccharides.
35) A solution contains 0.0000001(10-7) moles of hydroxyl ions [OH-] per liter. Which of the following best describes this solution?
E) neutral
39) Which of the structures contain(s) a carboxyl functional group?
E) none of the structures
40) In which of the structures are the atoms bonded by ionic bonds?
E) none of the structures
39) Which of the following solutions has the greatest concentration of hydroxyl ions [OH-]?
E) seawater at pH 8
61) Testosterone and estradiol are
E) steroids.
29) The molecule shown in Figure 5.3 is a
E) unsaturated fatty acid.
45) Which bond is closest to the carboxyl end of the molecule?
E- between the two C's on the right
43) Which is a carbonyl functional group?
looks like half of a cross, one O double bonded to -C-