AP BIOLOGY TEST 1-5
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?
0.5 kilocalories per gram of wax burned
Fluorine has an atomic number of 9 and a mass number of 19. How many electrons are needed to complete the valence shell of a fluorine atom?
1
Figure 5.8 Which of the following molecules contain(s) an aldehyde type of carbonyl functional group?
1 and 4
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?
1 × 10-10 mol of hydroxyl ion per liter of lake water
Life is diverse. How many species are estimated to be presently on the earth?
1,800,000
Figure 5.8 Which molecule is glycerol?
10
How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?
10
One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 L of a solution of pH 6?
10,000 times more
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?
10.0°C
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?
100 mL of household cleanser containing 0.5M ammonia
One liter of a solution pH 9 has how many more hydroxyl ions (OH -) than 1 L of a solution of pH 4?
100,000 times more
What is the atomic number of the cation formed in the reaction illustrated in Figure 2.3?
11
Figure 5.8 Which of the following molecules could be joined together by a phosphodiester type of covalent bond?
11 and 12
Figure 5.8 Which of the following combinations could be linked together to form a nucleotide?
11, 12, and 13
Figure 5.8 Which of the following molecules is the pentose sugar found in RNA?
12
A double-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines. This DNA molecule could be composed of
120 thymine and 120 adenine molecules.
Figure 5.8 Which of the following molecules is a purine type of nitrogenous base?
13
Figure 5.8 Which of the following statements is false?
14 and 15 could be joined together to form a polypeptide.
The atomic number of each atom is given to the left of each of the elements below. Which of the atoms has the same valence as carbon ( 12 C)? 6
14silicon
Figure 5.8 Which of the following molecules contains a glycosidic linkage type of covalent bond?
15
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)
150
How many neutrons are present in the nucleus of a phosphorus atom?
16
An atom with an atomic number of 9 and a mass number of 19 would have an atomic mass of approximately
19 daltons.
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)?
1Lof1.0 MNaCl
Figure 5.8 Which of the following molecules has (have) a functional group that frequently is involved in maintaining the tertiary structure of a protein?
2
How many electrons would be expected in the outermost electron shell of an atom with atomic number 12?
2
How many structural isomers are possible for a substance having the molecular formula C4H10?
2
What is the maximum number of covalent bonds an element with atomic number 8 can make with hydrogen?
2
What is the maximum number of electrons in a 2p orbital of an atom
2
What is the maximum number of electrons in the 1s orbital of an atom?
2
What is the valence of an atom with six electrons in its outer electron shell?
2
Figure 5.8 Which of the following molecules act as building blocks (monomers) of polypeptides?
2, 7, and 8
Calcium has an atomic number of 20 and an atomic mass of 40. Therefore, a calcium atom must have
20 protons.
How many different kinds of polypeptides, each composed of 12 amino acids, could be synthesized using the 20 common amino acids?
2012
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)
30
What is the approximate atomic mass of an atom with 16 neutrons, 15 protons, and 15 electrons?
31 daltons
If one strand of a DNA molecule has the sequence of bases 5ʹATTGCA3ʹ, the other complementary strand would have the sequence
3ʹTAACGT5ʹ.
A molecule of carbon dioxide (CO2) is formed when one atom of carbon (atomic number 6) is covalently bonded with two atoms of oxygen (atomic number 8). What is the total number of electrons that must be shared between the carbon atom and the oxygen atoms in order to complete the outer electron shell of all three atoms?
4
How many electron pairs does carbon share in order to complete its valence shell?
4
If a DNA sample were composed of 10% thymine, what would be the percentage of guanine?
40
At what temperature is water at its densest?
4°C
Figure 2.2 How many electrons does nitrogen have in its valence shell?
5
Figure 5.8 Which molecule has hydrophilic and hydrophobic properties and would be found in plasma membranes?
5
Figure 5.8 Which of the following molecules consists of a hydrophilic ʺheadʺ region and a hydrophobic ʺtailʺ region?
5
How many electrons does phosphorus have in its valence shell?
5
The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water?
55.6M
How many electrons does an atom of sulfur have in its valence shell?
6
How many molecules of glucose (C6H2O6 molecular mass =180 daltons) would be present in one mole of glucose?
6.02 × 1023
How many molecules of glycerol (C3H8O3) would be present in 1 L of a 1 M glycerol solution?
6.02 × 1023
You have a freshly-prepared 0.1M solution of glucose in water. Each liter of this solution contains how many glucose molecules?
6.02 × 1024
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?
6.02 × 1024
Figure 3.2 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)
60
Figure 5.8 Which of the following molecules is an amino acid with a hydrophobic R group or side chain?
7
Figure 5.8 Which of the following molecules could be joined together by a peptide bond as a result of a dehydration reaction?
7 and 8
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 w
7.0.
The atomic number of carbon is 6. Carbon-14 is heavier than carbon-12 because the atomic nucleus of carbon-14 contains _____ neutrons.
8
Figure 5.8 Which molecule is a saturated fatty acid?
9
Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein?
99
The atomic number of neon is 10. Therefore, which of the following is correct about an atom of neon?
A and B only
Which of the following effects is produced by the high surface tension of water?
A water strider can walk across the surface of a small pond.
One mole (mol) of a substance is
A) 6.02 × 1023 molecules of the substance. D) the molecular mass of the substance expressed in grams.
Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded proteins?
A) Alzheimerʹs B) Parkinsonʹs
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.
Figure 5.2 Which of the following statements is true regarding the molecule illustrated in Figure 5.2?
A) It is a saturated fatty acid. B) A diet rich in this molecule may contribute to atherosclerosis.
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.
Which of the following statements best describes the carbon atoms present in all organic molecules?
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.
Figure 2.3 What results from the chemical reaction illustrated in Figure 2.3?
A) a cation with a net charge of +1 D) an anion with a net charge of -1
A molecule with the chemical formula C6H12O6 is probably a
A) carbohydrate. B) lipid. C) monosaccharide
Which of the following properties or processes do we associate with living things?
A) evolutionary adaptations B) energy processing C) responding to the environment D) growth and reproduction E) ALL OF THE ABOVE
Which of the following descriptors is true of the molecule shown in Figure 5.1?
A) hexose C) glucose
Two species that belong to the same genus must also belong to the same
A) kingdom. B) phylum. C) class. D) order. E) ALL OF THE ABOVE
Altering which of the following levels of structural organization could change the function of a protein?
A) primary B) secondary C) tertiary D) quaternary
Which of the following is (are) true of natural selection?
A) requires genetic variation B) results in descent with modification C) involves differential reproductive success
The hydrogenation of vegetable oil results in which of the following?
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
Evolution is biologyʹs core theme that ties together all the other themes. This is because evolution explains
A) the unity and diversity of life. B) how organisms become adapted to their environment through the differential reproductive success of varying individuals. C) why distantly related organisms sometimes resemble each other. D) explains why some organisms have traits in common. E) ALL OF THE ABOVE
Dehydration reactions are used in forming which of the following compounds?
A) triacylglycerides B) polysaccharides C) proteins
The R group or side chain of the amino acid serine is —CH2OH. 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?
Alanine would be in the interior, and serine would be on the exterior of the globular protein.
Which of the following is a false statement regarding DNA?
All forms of life are composed of cells that have a membrane-enclosed nucleus.
Which of the following is true for this reaction? 3 H2 + N2 ↔ 2 NH3
Ammonia is being formed and decomposed.
Figure 4.6 Which is a hydroxyl functional group?
Answer: A
Figure 4.7 Which molecule is water soluble because it has a hydroxyl functional group
Answer: A
Which bond is closest to the N-terminus of the molecule?
Answer: A
Which drawing is of an atom with the atomic number of 6?
Answer: A
Which molecule can function as a base?
Answer: A
Which molecule contains an amino functional group, but is not an amino acid?
Answer: A
Which molecule is an alcohol?
Answer: A
Which of the following pairs of atoms would be most likely to form a covalent bond?
Answer: A
Which one of the atoms shown would be most likely to form a cation with a charge of +1?
Answer: A
Figure 4.8 Which molecule contains a sulfhydryl functional group?
Answer: B
Which drawing depicts an atom with a valence of 3?
Answer: B
Which drawing depicts the electron configuration of nitrogen ( 14 N)?
Answer: B
Which is a carbonyl functional group?
Answer: B
Which molecule has a carbonyl functional group in the form of an aldehyde?
Answer: B
Which molecule is a thiol?
Answer: B
Which of the following pairs of atoms would be most likely to form an ionic bond?
Answer: B
Figure 5.6 At which bond would water need to be added to achieve hydrolysis of the peptide, back to its component amino acid?
Answer: C
Which bond is a peptide bond?
Answer: C
Which drawing depicts an atom with a valence of 2?
Answer: C
Which drawing depicts the electron configuration of oxygen ( 16 O)?
Answer: C
Which is a carboxyl functional group?
Answer: C
Which is an acidic functional group that can dissociate and release H+ into a solution?
Answer: C
Which molecule has a carbonyl functional group in the form of a ketone?
Answer: C
Which is a basic functional group that can accept H+ and become positively charged?
Answer: D
Which is an amino functional group?
Answer: D
Which molecule can increase the concentration of hydrogen ions in a solution and is therefore an organic acid?
Answer: D
Which molecule contains a carboxyl group?
Answer: D
Which molecule functions to transfer energy between organic molecules?
Answer: D
Which molecule is an organic phosphate?
Answer: D
Which one of the atoms shown would be most likely to form an anion with a charge of -1?
Answer: D
Which bond is closest to the carboxyl end of the molecule?
Answer: E
Which drawing depicts an atom that is inert or chemically unreactive?
Answer: E
Which drawing depicts the electron configuration of neon ( 20 Ne)? 10
Answer: E
Which is a functional group that helps stabilize proteins by forming covalent cross-links within or between protein molecules?
Answer: E
A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is its most likely classification?
Archaea
Which molecules contain a carbonyl group?
B and C
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)
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)
From its atomic number of 15, it is possible to predict that the phosphorus atom has
B) 15 protons. C) 15 electrons.
Which of the following would be regarded as compounds?
B) H2O D) CH4
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).
If the pH of a solution is decreased from 9 to 8, it means that the
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.
Buffers are substances that help resist shifts in pH by
B) donating H+ to a solution when they have been depleted. D) accepting H+ when the are in excess.
Prokaryotes are classified as belonging to two different domains. What are the domains?
Bacteria and Archaea
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?
Blood pH will decrease slightly.
Figure 4.5 Which of the structures is an impossible covalently bonded molecule?
C
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)
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)
Which of the pairs of molecular structures shown below do NOT depict enantiomers (enantiomeric forms) of the same molecule?
C)
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
C) Item (A) is exactly or very approximately equal to item (B).
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?
C18H30O15
The molecule shown here could be described in chemical symbols as
CH4.
All of the following statements are part of Charles Darwinʹs concept of natural selection except
Characteristics of organisms are inherited as genes on chromosomes.
What is the difference between covalent bonds and ionic bonds?
Covalent bonds involve the sharing of electrons between atoms, and ionic bonds involve the electrical attraction between atoms.
Which of the pairs of molecular structures shown below depict enantiomers (enantiomeric forms) of the same molecule?
D)
Which of the following is a false statement regarding deoxyribonucleic acid (DNA)?
DNA is an enzyme that puts together amino acids to make a protein.
Which of the following statements best summarizes the structural differences between DNA and RNA?
DNA nucleotides contain a different sugar than RNA nucleotides.
Which of the following best describes the flow of information in eukaryotic cells?
DNA → RNA → proteins
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?
Different enantiomers may have different or opposite physiological effects
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?
Dissolve 180 g of glucose in water, and then add more water until the total volume of the solution is 1 L.
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?
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.
Nitrogen (N) is much more electronegative than hydrogen (H). Which of the following statements is correct about the atoms in ammonia (NH3)?
Each hydrogen atom has a partial positive charge.
A common form of regulation in which accumulation of an end product of a process slows that process is called positive feedback.
FALSE
A theory in science is equivalent in scope to a well-structured hypothesis.
FALSE
Charles Darwin presented verifiable evidence that supported the view that life can arise by spontaneous generation.
FALSE
The goal of systems biology is to construct models to predict the emergent properties of cells.
FALSE
Which of the following best describes chemical equilibrium?
Forward and reverse reactions continue with no effect on the concentrations of the reactants and products.
Which of the following people was the first to synthesize an organic compound, urea, from inorganic starting materials?
Friedrich Wohler
Which of the following peopleʹs synthesis of this compound from inorganic starting materials provided evidence against vitalism?
Friedrich Wohler
Which of the following molecules contains the strongest polar covalent bond?
H2O
Which of the following ionizes completely in solution and is considered to be a strong acid?
HCl
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?
HSH
Which of the following people synthesized an organic compound, acetic acid, from inorganic substances that had been prepared directly from pure elements?
Hermann Kolbe
Which of the following peopleʹs synthesis of this compound from inorganic starting materials provided evidence against vitalism?
Hermann Kolbe
Why does ice float in liquid water?
Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.
Which of these is based on a deduction?
If I turn the key in the ignition while stepping on the gas pedal, then my car will start.
Which of the following is true of cellulose?
It is a major structural component of plant cell walls.
Figure 5.5 Which of the following statements is/are true regarding the chemical reaction illustrated in Figure 5.5?
It results in a peptide bond.
A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound?
It should dissolve in water.
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.
Item (A) is greater than item (B).
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
Item (A) is greater than item (B).
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 acid
Item (A) is less than item (B).
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?
Jakob Berzelius
Which of the following takes place as an ice cube cools a drink?
Kinetic energy in the drink decreases.
The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride?
MgCl2
Figure 5.3 Which of the following statements is true regarding the molecule illustrated in Figure 5.3?
Molecules of this type are usually liquid at room temperature.
Which of the following statements is completely correct?
NH3 is a weak base (alkali), and HCl is a strong acid.
In ammonium chloride salt (NH4Cl) the anion is a single chloride ion, Cl-. What is the cation of NH4Cl?
NH4 with a charge of +1
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.
NaCl crystals will dissolve readily in water but will not dissolve in methanol.
Which of the following ionizes completely in solution and is considered to be a strong base (alkali)?
NaOH
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
None of the other answer choices correctly describes these solutions.
Which of the following statements concerning prokaryotic and eukaryotic cells is not correct?
Prokaryotic cells contain small membrane-enclosed organelles.
Which of the following statements is false?
Protons and electrons are electrically charged particles. Protons have one unit of negative charge, and electrons have one unit of positive charge.
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?
Stanley Miller
Which of the following people used this apparatus to study formation of organic compounds?
Stanley Miller
Discovery science has contributed much to our understanding of nature without most of the steps of the so-called scientific method.
TRUE
Discovery science uses inductive reasoning to derive generalizations from a large number of specific observations.
TRUE
In hypothesis-based science, deductive reasoning is used to predict a result that would be found if a particular hypothesis is correct.
TRUE
Recent evidence points to the conclusion that the ancestral finches of the Galapagos originated in the islands of the Caribbean.
TRUE
Science requires that hypothesis be testable and falsifiable and that observations be repeatable.
TRUE
Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other?
Testosterone and estradiol have different functional groups attached to the same carbon skeleton.
Which of the following statements about the 5ʹ end of a polynucleotide strand of DNA is correct?
The 5ʹ end has a phosphate group attached to the number 5 carbon of ribose.
Why are hydrocarbons insoluble in water?
The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
The nucleus of a nitrogen atom contains 7 neutrons and 7 protons. Which of the following is a correct statement concerning nitrogen?
The nitrogen atom has a mass number of 14 and an atomic mass of approximately 14 daltons.
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?
The pH of the beakerʹs contents falls.
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?
The phosphodiester bonds between deoxyribose sugars would be broken.
Which of the following describes any reaction that has reached chemical equilibrium?
The rate of the forward reaction is equal to the rate of the reverse reaction.
Which of the following best describes the relationship between the atoms described below? Atom 1 Atom 2 31P 32P 15 15
They are both isotopes of phosphorus.
Which of the following best describes the relationship between the atoms described below? Atom 1 Atom 2 1 1 H 31 H
They are both isotopes.
Which of the following is true of both starch and cellulose?
They are both polymers of glucose.
Which of the following is a false statement concerning amino groups?
They are nonpolar.
Which of the following statements is false for the class of biological molecules known as lipids?
They are soluble in water.
Why are human sex hormones considered to be lipids?
They are steroids, which are not soluble in water.
Which of the following is true regarding saturated fatty acids?
They are the principal molecules in lard and butter.
All of the following statements concerning saturated fats are true except
They have multiple double bonds in the carbon chains of their fatty acids.
Which of the following statements correctly describes geometric isomers?
They have variations in arrangement around a double bond.
Which of the following statements is true about buffer solutions?
They maintain a relatively constant pH when either acids or bases are added to them.
Three or four of the following statements are true and correct. Which one, if any, is false? If all the statements are true, choose answer E.
Virtually all organisms require the same elements in the same quantities
Why is it important that an experiment include a control group?
Without a control group, there is no basis for knowing if a particular result is due to the variable being tested or to some other factor.
Roger Kornberg used this method for elucidating the structure of RNA polymerase.
X-ray crystallography
Which is the best description of a carbonyl group?
a carbon atom joined to an oxygen by a double covalent bond
A group of molecular biologists is trying to synthesize a new artificial compound to mimic the effects of a known hormone that influences sexual behavior. They have turned to you for advice. Which of the following compounds is most likely to mimic the effects of the hormone?
a compound with the same three-dimensional shape as part of the hormone
Which of the following is not considered to be a weak molecular interaction?
a covalent bond
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 decrease in the concentration of H2CO3 and an increase in the concentration of H2O.
Sometimes atoms form molecules by sharing two pairs of valence electrons. When this occurs, the atoms are said to be joined by
a double covalent bond.
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 hydrogen bond
What is a triacylglycerol?
a lipid made with three fatty acids and glycerol
The illustration above represents
a map of a network of protein interactions within a eukaryotic cell.
Which of the following descriptions best fits the class of molecules known as nucleotides?
a nitrogenous base, a phosphate group, and a pentose sugar
What results from an unequal sharing of electrons between atoms?
a polar covalent bond
When applying the process of science, which of these is tested?
a prediction
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 steroid
What is a hypothesis?
a tentative explanation that can be tested and is falsifiable
Waterʹs high specific heat is mainly a consequence of the
absorption and release of heat when hydrogen bonds break and form.
A given solution contains 0.0001(10-4) moles of hydrogen ions [H+] per liter. Which of the following best describes this solution?
acidic: H+ donor
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?
amino
Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen?
an amino acid such as glycine
Electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a possible result is that
an electron may move to an electron shell farther out from the nucleus.
Which of these individuals is most likely to be successful in an evolutionary sense?
an organism that dies after 5 days of life but leaves 10 offspring, all of whom survive to reproduce
What method did Frederick Sanger use to elucidate the structure of insulin?
analysis of amino acid sequence of small fragments
Oxygen has an atomic number of 8 and a mass number of 16. Thus, the atomic mass of an oxygen atom is
approximately 16 daltons.
Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope?
archaea
Research indicates that Ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that
are mirror images of one another.
Thalidomide and L-dopa, shown below, are examples of pharmaceutical drugs that occur as enantiomers, or molecules that
are mirror images of one another.
Polysaccharides, lipids, and proteins are similar in that they
are synthesized from monomers by dehydration reactions.
Figure 4.2 Shown here in Figure 4.2 are the structures of glucose and fructose. These two molecules differ in the
arrangement of carbon, hydrogen, and oxygen atoms.
Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?
as a disaccharide
Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. Which of the following indicates the number of protons in an atomʹs nucleus?
atomic number
Atoms whose outer electron shells contain eight electrons tend to
be stable and chemically nonreactive, or inert.
Which of the following uses the amino acid sequences of polypeptides to predict a proteinʹs three-dimensional structure?
bioinformatics
Organic chemistry is a science based on the study of
carbon compounds.
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?
carbon, hydrogen, nitrogen, oxygen
Amino acids are acids because they always possess which functional group?
carboxyl
What is the name of the functional group shown in Figure 4.4?
carboxyl
Which two functional groups are always found in amino acids?
carboxyl and amino
Which functional groups can act as acids?
carboxyl and phosphate
The lowest level of biological organization that can perform all the activities required for life is the
cell-for example, a skin cell.
On food packages, to what does the term ʺinsoluble fiberʺ refer?
cellulose
What is the term used for a protein molecule that assists in the proper folding of other proteins?
chaperonin
Which of the following polymers contain nitrogen?
chitin
The ionic bond of sodium chloride is formed when
chlorine gains an electron from sodium.
All of the following contain amino acids except
cholesterol.
What is the structural feature that allows DNA to replicate?
complementary pairing of the nitrogenous bases
If the pH of a solution is increased from pH 5 to pH 7, it means that the
concentration of OH- is 100 times greater than what it was at pH 5.
The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA
contains one less oxygen atom.
A carbon atom is most likely to form what kind of bond(s) with other atoms?
covalent
Which of the following are nitrogenous bases of the pyrimidine type?
cytosine and uracil
What is the chemical mechanism by which cells make polymers from monomers?
dehydration reactions
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?
denaturation
There are 20 different amino acids. What makes one amino acid different from another?
different side chains (R groups) attached to an alpha (α) carbon
The method of scientific inquiry that describes natural structures and processes as accurately as possible through careful observation and the analysis of data is known as
discovery science.
Collecting data based on observation is an example of __________; analyzing this data to reach a conclusion is an example of __________ reasoning.
discovery science; inductive
A strong covalent bond between amino acids that functions in maintaining a polypeptideʹs specific three-dimensional shape is a (an)
disulfide bond.
A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism?
domain Eukarya, kingdom Fungi
Van der Waals interactions result when
electrons are not symmetrically distributed in a molecule.
Which of the following is reflective of the phrase ʺthe whole is greater than the sum of its partsʺ?
emergent properties
A type of protein critical to all cells is organic catalysts called
enzymes.
Species that are in the same __________ are more closely related than species that are only in the same __________.
family; order
A molecule with the formula C18H36O2 is probably a
fatty acid.
Of the following functions, the major purpose of RNA is to
function in the synthesis of protein.
Which of the following solutions has the greatest concentration of hydrogen ions [H +]?
gastric juice at pH 2
Figure 4.3 The two molecules shown in Figure 4.3 are best described as
geometric isomers.
Which of the following is not a polymer?
glucose
All of the following are polysaccharides except
glycogen
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?
glycogen
In a hypothetical world, every 50 years people over 6 feet tall are eliminated from the population. Based on your knowledge of natural selection, you would predict that the average height of the human population will
gradually decline.
Which of the following are nitrogenous bases of the purine type?
guanine and adenine
In the double helix structure of nucleic acids, cytosine hydrogen bonds to
guanine.
Humans can digest starch but not cellulose because
humans have enzymes that can hydrolyze the alpha (α) glycosidic linkages of starch but not the beta (β) glycosidic linkages of cellulose.
In the methane molecule shown here, bonds have formed that include both the s orbital valence electrons of the hydrogen atoms and the p orbital valence electrons of the carbon. The electrons in these bonds are said to have
hybrid orbitals.
Which of the following explains most specifically the attraction of water molecules to one another?
hydrogen bond
What gives rise to the cohesiveness of water molecules?
hydrogen bonds
What maintains the secondary structure of a protein?
hydrogen bonds
Which type of bond must be broken for water to vaporize?
hydrogen bonds
Which type of interaction stabilizes the alpha (α) helix and the beta (β) pleated sheet structures of proteins?
hydrogen bonds
Charles Darwin proposed a mechanism for descent with modification which stated that organisms of a particular species are adapted to their environment when they possess
inheritable traits that enhance their survival and reproductive success in the local environment.
Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates?
iodine
Which of the following results from a transfer of electron(s) between atoms?
ionic bond
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
is more closely related to frogs than to humans.
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?
isotopes
Which of these is reflective of the hierarchical organization of life from most to least inclusive?
kingdom, phylum, class, order, family, genus, species
The main source of energy for producers in an ecosystem
light energy.
Which of the following is a diverse group of hydrophobic molecules?
lipids
The experimental approach taken in current biological investigations presumes that
living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena.
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
maltose
The molecule shown here is the simplest of organic compounds. It is called
methane.
Which of the following sequences represents the hierarchy of biological organization from the least to the most complex level?
molecule, cell, organ system, population, ecosystem, biosphere
Which of these is a correct representation of the hierarchy of biological organization from least to most complex?
molecule, intestinal cell organelle, intestinal cell, intestinal tissue, digestive system, organism
The element nitrogen is present in all of the following except
monosaccharides.
Through time, the lineage that led to modern whales shows a change from four -limbed land animals to aquatic animals with two limbs that function as flippers. This change is best explained by
natural selection.
When blood glucose level rises, the pancreas secretes insulin, and as a result blood glucose level declines. When blood glucose level is low, the pancreas secretes glucagon, and as a result blood glucose level rises. Such regulation of blood glucose level is the result of
negative feedback.
A solution contains 0.0000001(10-7) moles of hydroxyl ions [OH-] per liter. Which of the following best describes this solution?
neutral
In which of the structures are the atoms bonded by ionic bonds?
none of the structures
Which of the structures contain(s) a carboxyl functional group?
none of the structures
When two atoms are equally electronegative, they will interact to form
nonpolar covalent bonds.
Hydrophobic substances such as vegetable oil are
nonpolar substances that repel water molecules.
Which of the following store and transmit hereditary information?
nucleic acids
How do isotopes of the same element differ from each other?
number of neutrons
A covalent bond is likely to be polar when
one of the atoms sharing electrons is much more electronegative than the other atom.
A covalent chemical bond is one in which
outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms.
What is the pH of a solution with a hydroxyl ion [OH-] concentration of 10-12 M?
pH 2
What is the pH of a solution with a hydrogen ion [H+] concentration of 10-8 M?
pH 8
Which bonds are created during the formation of the primary structure of a protein?
peptide bonds
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
polar covalent bonds.
A localized group of organisms that belong to the same species is called a
population.
Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of
positive feedback.
Based on your knowledge of the polarity of water molecules, the solute molecule is most likely
positively charged.
Enzymes are
proteins.
The mass number of an element can be easily approximated by adding together the number of __________ in an atom of that element.
protons and neutrons
In order to understand the chemical basis of inheritance, one must understand the molecular structure of DNA. This is an example of the application of __________ to the study of biology.
reductionism
Which of the following is not a theme that unifies biology?
reductionism
The bonding of two amino acid molecules to form a larger molecule requires which of the following?
removal of a water molecule
Prokaryotic and eukaryotic cells generally have which of the following features in common?
ribosomes
Which of the following solutions has the greatest concentration of hydroxyl ions [OH-]?
seawater at pH 8
The α helix and the β pleated sheet are both common polypeptide forms found in which level of protein structure?
secondary
Figure 5.7 best illustrates the
secondary structure of a polypeptide.
In terms of the hierarchical organization of life, a bacterium is at the __________ level of organization, whereas a human is at the __________ level of organization.
single-celled organism; multicellular organism
Figure 5.4 What is the structure shown in Figure 5.4?
steroid molecule
Testosterone and estradiol are
steroids.
Figure 4.1 The two molecules shown in Figure 4.1 are best described as
structural isomers.
Shown here in Figure 4.2 are the structures of glucose and fructose. These two molecules are
structural isomers.
Based on electron configuration, which of these elements would exhibit chemical behavior most like that of oxygen?
sulfur
For most ecosystems __________ is (are) the ultimate source of energy, and energy leaves the ecosystem in the form of __________.
sunlight; heat
Which branch of biology is concerned with the naming and classifying of organisms?
taxonomy
The application of scientific knowledge for some specific purpose is known as
technology.
At which level of protein structure are interactions between the side chains (R groups) most important?
tertiary
An example of a hydrogen bond is the bond between
the H of one water molecule and the O of another water molecule.
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
the HCO3- to act as a base and remove excess H+ with the formation of H2CO3.
Which of the following statements correctly defines a kilocalorie?
the amount of heat required to raise the temperature of 1 kg of water by 1°C
Water is able to form hydrogen bonds because
the bonds that hold together the atoms in a water molecule are polar covalent bonds.
Pure, freshly-distilled water has a pH of 7. This means that
the concentration of H+ ions in the water equals the concentration of OH- ions in the water.
The dynamics of any ecosystem include the following major processes:
the flow of energy from sunlight to producers and then to consumers, and the recycling of chemical nutrients.
A van der Waals interaction is the weak attraction between
the nucleus of one molecule and the electrons of a nearby molecule.
Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into
the potential energy of chemical bonds.
Which of the following is an example of hydrolysis?
the reaction of a fat, forming glycerol and fatty acids with the utilization of water
The bonding of two amino acid molecules to form a larger molecule requires
the release of a water molecule.
Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon?
the release of heat by the formation of hydrogen bonds
Which of these provides evidence of the common ancestry of all life?
the universality of the genetic code
A controlled experiment is one in which
there are at least two groups, one of which does not receive the experimental treatment.
Figure 5.8 A fat (or triacylglycerol) would be formed as a result of a dehydration reaction between
three molecules of 9 and one molecule of 10.
The hybrid orbitals in a molecule of methane are oriented
toward the corners of a tetrahedron centered on the carbon atom.
One difference between carbon-12 (12 C) and carbon-14 (14 C) is that carbon-14 has
two more neutrons than carbon-12.
3 H is a radioactive isotope of hydrogen. One difference between hydrogen-1 (1 H) and hydrogen-3 ( 31 H) is that hydrogen-3 has
two more neutrons than hydrogen-1.
The tertiary structure of a protein is the
unique three-dimensional shape of the fully folded polypeptide.
The molecule shown in Figure 5.3 is a
unsaturated fatty acid.
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
vitalism.
Research indicates that acid precipitation can damage living organisms by
washing away certain mineral ions that help buffer soil solution and are essential nutrients for plant growth.
A carbon skeleton is covalently bonded to both an amino group and a carboxyl group. When placed in water it
would function as both an acid and a base.
Figure 5.7 The structure depicted in Figure 5.7 shows the
α helix secondary structure of a polypeptide.