AP Biology

Unit 1 Homework Set (CH. 2 – 6)

Name: ______

Instructions:

Read each question carefully before answering. Work at a steady pace, and you should have ample time to finish.

------

___ 1. The atomic number of neon is 10. Therefore, it

1. has 8 electrons in the outer electrons shell.

2. is inert.

3. has an atomic mass of 10.

a. 1

b. 2

c. 3

d. Only 1 and 2 are correct

e. 1, 2, and 3 are correct.

___ 2. An atomic form of an element containing different numbers of neutrons is

a. an isotope.

b. an ion.

c. a polar atom.

d. an isomer.

e. radioactive.

___ 3. What are the chemical properties of atoms whose outer electron shells contain eight electrons?

a. They form ionic bonds in aqueous solutions.

b. They form covalent bonds in aqueous solutions.

c. They are particularly stable and nonreactive

d. The tend to be gases.

e. They are particularly stable and nonreactive AND they tend to be gases.

------

Use the choices below to answer the following question(s). Each choice may be used once, more than once, or not at all.

1. nonpolar covalent molecule

2. polar covalent bond

3. ionic bond

4. hydrogen bond

5. hydrophobic interaction

___ 4. Results from a transfer of election(s) between atoms.

a. 1

b. 2

c. 3

d. 4

e. 5

___ 5. Results from an unequal sharing of elections between atoms.

a. 1

b. 2

c. 3

d. 4

e. 5

___ 6. What is the maximum number of covalent bonds an element with atomic number 15 can make with hydrogen?

a. 1

b. 2

c. 3

d. 4

e. 0

------

Use the information extracted from the periodic table in Figure 2.1 to answer the following question(s).

Atomic Mass ------>

Atomic Number ---->

Figure 2.1

___ 7. How many electrons does carbon have in its outermost (valence) energy level?

a. 4

b. 8

c. 7

d. 5

e. 2

___ 8. The atomic number of each atom is given at left. Which of the atoms has the same valence as carbon?

a. 7 nitrogen

b. 9 fluorine

c. 10 neon

d. 12 magnesium

e. 14 silicon

___ 9. Which of the following is a trace element that is essential to humans?

a. nitrogen

b. calcium

c. iodine

d. carbon

e. oxygen

___10. A covalent bond is likely to be polar when

a. one of the atoms sharing electrons is much more electronegative than the other.

b. the two atoms sharing electrons are equally electronegative.

c. the two atoms sharing electrons are of the same element.

d. it is between two atoms that are both very strong electron acceptors.

e. it joins a carbon atom to a hydrogen atom.

___ 11. What bonds are easily disrupted in aqueous solutions?

a. covalent

b. polar covalent

c. ionic

d. only covalent and polar covalent

e. covalent, polar

___ 12. From its atomic number of 15, it is possible to predict that the phosphorus atom has

a. 15 neutrons

b. 15 protons

c. 15 electrons.

d. 15 protons and 15 electrons.

e. 15 neutrons, 15 protons, and 15 electrons.

___ 13. The ionic bond of sodium chloride is formed when

a. chlorine gains an electron from sodium.

b. sodium and chlorine share an electron pair.

c. sodium and chlorine both lose electrons from their outer energy levels.

d. sodium gains a electron from chlorine.

e. chlorine gains a proton from sodium.

___ 14. Magnesium has the atomic number of 12. What kind of bonds does it form with chlorine (atomic number of 17) and what is the formula for magnesium chloride?

a. covalent, MgCl

b. ionic, MgC2

c. covalent, Mg2Cl

d. ionic, MgCl

e. ionic, ClMg

------

Refer to Figure 2.2 to answer the following question(s).

___ 15. Which of the drawings depicts the electron configuration of neon?

___ 16. Which of the drawings depicts the electron configuration of the carbon?

------

Refer to the numbers below to answer the following questions. Each number may be used once, more than once, or not at all.

12345

___ 17. The number of electrons carob shares with oxygen molecules in a molecule of CO2.

a. 1

b. 2

c. 3

d. 4

e. 5

___ 18. The maximum number of electrons in the 1s orbital.

a. 1

b. 2

c. 3

d. 4

e. 5

___ 19. Which four elements make up approximately 96% of living matter?

a. carbon, hydrogen, nitrogen, and oxygen

b. carbon, sulfur, phosphorus, and hydrogen

c. oxygen, hydrogen, calcium, sodium

d. carbon, sodium, chlorine, magnesium

e. carbon, oxygen, sulfur, calcium

___ 20. How many electrons would be expected in the outer energy level of an atom with an atomic number 17?

a. equal numbers of isotopes.

b. ions.

c. polar covalent bonds.

d. nonpolar covalent bonds.

e. ionic bonds.

___ 22. The combining properties of an atom depend on the number of

a. valence shells in the atom.

b. orbital found in the atom.

c. electrons in each orbital in the atom.

d. electrons in the outer valence shell in the atom.

e. hybridized orbital in the atom.

___ 23. Atoms whose outer electron shells contain eight electrons tend to

a. form ionic bonds in aqueous solutions.

b. form covalent bonds in aqueous solutions.

c. be particularly stable and nonreactive.

d. be particularly unstable and very reactive.

e. be biologically important since they are present in organic molecules.

24. A covalent chemical bond is one in which

a. electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged.

b. protons or neutrons are shared by two atoms so as to satisfy the requirements of both.

c. outer shell electrons are shared by two atoms so as to satisfactorily fill the outer electron shells of both.

d. outer shell electrons on one atom are transferred to the inner electron shells of another atom.

e. the inner shell electrons of one atom are transferred to outer shell of another atom.

___ 25. If atom 6X (atomic number 6) were allowed to react with hydrogen, the molecule formed would be

a. X – H

b. H – X – H

c. H – X – H

H

d. H

H – X – H

H

e. H = X = H

___ 26. The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called?

a. a covalent bond

b. a hydrogen bond

c. a am ionic bond

d. a hydration shell

e. a hydrophobic bond

___ 27. Life on earth is dependant on all the properties of water as well as the abundance of water. Which property of water is probably most important for the functioning of organisms at the molecular level?

a. cohesion and high surface tension

b. high specific heat

c. high hear of vaporization

d. expansion upon freezing

e. versatility as a solvent

___ 28. What would be the pH of a solution with a hydroxyl ion concentration (OH-) of 10?

a. 2

b. 4

c. 8

d. 10

e. 14

___ 29. Which of the following statements about water is correct?

a. Water is more dense as a solid than it is as a liquid

b. Water is more dense at 100 C than it is at 37 C.

c. Water is a good solvent for lipids.

d. Compared to most other substances, the temperature of water rises sharply when it

absorbs heat.

e. Compared to most liquids, the evaporation of water requires a large amount of heat.

___ 30. What do the following have in common with reference to water: cohesion, surface tension, specific heat?

a. All are products of the structure of the hydrogen atom.

b. All are produced by covalent bonds.

c. All are properties related to hydrogen bonding.

d. All have to do with polarity of water molecules.

e. All are aspects of a semi-crystalline structure.

___ 31. Assume that acid rain has lowered the pH of a particular lake to pH 5.0. What is the hydroxide ion concentration of this lake?

1. 1 x 10-5moles of hydroxide ion per liter of lake water

2. 1 x 10-9 moles of hydroxide ion per liter of lake water.

3. 5.0 molar with regard to hydroxide ion concentration

4. 9.0 molar with regard to hydroxide ion concentration.

a. 1

b. 2

c. 3

d. 4

e. Both 2 and 4 are correct.

___ 32. The nutritional information on a cereal box shows that one serving of dry cereal has 90 calories (large C). If one were to burn a serving of cereal in a bomb calorimeter, the amount of heat given off would be sufficient to raise the temperature of one kilogram of water how many degrees Celsius?

a. 0.9 Celsius

b. 9.0 Celsius

c. 90.0 Celsius

d. 900.0 Celsius

e. 9000.0 Celsius

___ 33. The formation of ice during colder weather helps to temper the seasonal transition to winter. This is mainly because

a. the formation of hydrogen bonds releases heat.

b. the formation of hydrogen bonds absorbs heat.

c. there is less evaporative cooling of lakes.

d. ice melts each autumn afternoon.

e. ice is warmer than the winter air.

___ 34. The molecular mass of glucose is 180g. To make a one-molar solution of glucose, you should do which of the following?

a. Dissolve 100g of glucose in a liter of water.

b. Dissolve 180g of glucose in a gallon water.

c. Dissolve 180g of glucose in 100 grams of water.

d. Dissolve 180mg (milligrams) of glucose in one liter of water.

e. Dissolve 180g of glucose in water, and then add more water until the toal volume of the solution is one liter.

___ 35. In a lake contaminated by acid rain, fish generally die when the water is persistently below which pH?

a. 8

b. 7

c. 6.5

d. 6

e. 5

------

Refer to Figure 3.2 to answer the following question(s).

Atomic Mass ------>

Atomic Number ---->

H H O

N – C – C – OH

H H

___ 36. How many grams of the molecule sown above would constitute a mole of the substance?

a. 32

b. 40

c. 75

d. 114

e. 6.02 x 1023

___ 37. How would one make a 0.5-M solution of the molecule shown above?

1. Mix 0.5 grams with enough water to yield 1 liter of solution.

2. Mix 20 grams with enough water to yield 1 liter of solution.

3. Dissolve 37.5 grams with enough water to yield 1 liter of solution.

4. Dissolve 75 grams in a 0.5 liter of water.

a. 1

b. 2

c. 3

d. 4

e. Only 1 and 4 will yield a 0.5M solution?

___ 38. How many grams of the molecule show below should one add to a liter of water to make a 0.2-M solution?

H O

||

H – C – C – O – H

H

a. 8

b. 12

c. 24

d. 32

e. 60

___ 39. Which of the following ionizes completely in solution and is therefore a strong acid?

a. NaOH

b. H2CO3

c. CH3COOH

d. NH2

e. HCl

___ 40. It is correct to say that the action of buffers

a. is of relatively little significance in living systems.

b. tends to prevent great fluctuations in pH.

c. depends on the formation of a great number of hydrogen ions.

d. depends on the presence of many electron donors.

e. is to remove hydroxyl ions from organic acids.

___ 41. A given solution is found to contain 0.0001 mole of hydrogen ion (H+). Which of the following best describes this solution?

a. acidic: H+ acceptor

b. basic: H+ acceptor

c. acidic: H+ donor

d. basic: H+ donor

e. neutral

___ 42. What do cohesion, surface tension, and adhesion have in common with reference to water?

a. All are products of the structure of the hydrogen atom.

b. All are produced by covalent bonding.

c. All are properties related to hydrogen bonding.

d. All have to do with nonpolar covalent bonds.

e. All are aspects of crystalline structure.

------

Use the terms below to answer the following question(s). Each term may be used once, more than once, or not at all.

1. calorie

2. temperature

3. heat of vaporization

4. mole

___ 43. A measure of the average kinetic energy of the molecules in a body of matter.

a. 1

b. 2

c. 3

d. 4

e. 5

___ 44. Which of the following is a correct definition of a kilocalorie?

a. The amount of heat required to raise 1 gram of water by one degree Fahrenheit.

b. The amount of heat energy required to raise 1 gram of water by ten degrees Celsius.

c. The amount of heat energy required to raise 1 kilogram of water by one degree Celsius.

d. A measure of the average kinetic energy of a pint of water.

e. The amount of energy in one kilogram of glucose.

___ 45. At what temperature is water at its densest?

a. 0° C

b. 4° C

c. 32° C

d. 100° C

e. 212° C

___ 46. A compound contains hydroxyl groups as its predominate functional group. Which of the following statements is true concerning this compound?

a. It is probably a lipid.

b. I should dissolve in water.

c. It should dissolve in a non-polar solvent.

d. It won’t form hydrogen bonds with water.

e. It is hydrophobic.

___ 47. Which of the following elements is the most abundant (percent dry weight) in both humans and E. coli?

a. oxygen

b. carbon

c. hydrogen

d. nitrogen

e. phosphorus

___ 48. What is the reason why hydrocarbons are not soluble in water?

a. They are hydrophilic

b. The C-H bond is non-polar.

c. They do not ionize

d. They are large molecules.

e. They are lighter than water.

___ 49. Glucose and fructose differ in

1. The number of carbon, hydrogen, and oxygen atoms

2. The types of carbon, hydrogen, and oxygen atoms.

3. The arrangement of carbon, hydrogen, and oxygen atoms.

a. 1

b. 2

c. 3

d. Only 1 and 2 are correct.

e. 1, 2, 3 are correct.

___ 50. What is the name of the function groups below?

O

//

R – C

\

O – H

a. carbonyl

b. methyl

c. dehydroxyl

d. carbonxyl

e. acetyl

___ 51. Forms covalent cross links within or between protein molecules.

a. 1

b. 2

c. 3

d. 4

e. 5

___ 52. Polar confers solubility in water.

a. 1

b. 2

c. 3

d. 4

e. 5

___ 53. Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen?

a. alcohol such as ethanol

b. a compound such as glycerol

c. a steroid such as testosterone

d. amino acid such as glycine

e. a hydrocarbon such as benzene

------

Refer to the molecule shown in Figure 4.4 to answer the following question(s).

1. H H 2. H H O3. H O H

| | | | // | || |

H – C – C – OH C – C – H H – C – C – C – H

| | \ | |

H H H H H

4. H O 5. H H

| // | /

H – C – C H – C – N Figure 4.4

| \ | \

H OH H H

___ 54. Which molecule contains a carboxyl group?

a. 1

b. 2

c. 3

d. 4

e. 5

___ 55. Which two of the molecules above contain a carbonyl group?

a. 1 and 2

b. 2 and 3

c. 3 and 4

d. 4 and 5

e. 1 and 5

___ 56. Which of the above is water soluble because it has a functional group that is an alcohol?

a. 1

b. 2

c. 3

d. 4

e. 5

__ 57. Which of the following is a false statement concerning amine groups?

a. They are basic.

b. They are found in amino acids.

c. They contain nitrogen.

d. They are nonpolar

e. They are components of urea.

58. Which two functional groups are always found in amino acids?

a. amine and sulfhydryl

b. carbonyl and carboxyl

c. carbonxyl and amine

d. alcohol and aldehyde

e. ketone and amine

59. Which of the following is the best description of organic compounds?

a. carbon atoms covalently bonded to other carbon atoms

b. polymers composed of many monomer subunits

c. compounds with covalent bonds that are unequally shared with other atoms

d. compounds all containing carbon, hydrogen, oxygen, and nitrogen

e. carbon compounds all having a linear order of atoms

60. Which functional groups can act as acids?

a. amine and sulfhydrl

b. carbonyl and carboxyl

c. carboxyl and phosphate

d. alcohol and aldehyde

e. ketone and amine

61. Which type of lipid is most important in biological membranes?

a. fats

b. steroids

c. phospholipids

d. oils

e. triglycerides

62. Which types of interaction stabilizes the alpha helix structure of proteins?

a. hydrophobic interactions

b. non-polar covalent bonds

c. ionic Interactions

d. hydrogen bonds

e. polar covalent bonds

63. What is the molecule illustrated below?

O H H H H H H H H H H H H H H H

\\ | | | | | | | | | | | | | | |

C – C – C – C – C – C – C – C – C – C – C – C – C – C – C – C – H

/ | | | | | | | | | | | | | | |

OH H H H H H H H H H H H H H H H

a. a saturated fatty acid

b. An unsaturated fatty acid

c. a polyunsaturated triglyceride

d. likely to be a common component of plat oils

e. similar in structure to a steroid

64. What is the structure shown in Figure 5.2

Figure 5.2

a. a starch molecule

b. a steroid

c. a protein

d. a cellulose molecule

e. a nucleic acid polymer

___ 65. Which of the following is true both of starch and of cellulose?

a. They are both polymers of glucose.

b. They are geometric isomers of each other.

c. They can both be digested by humans.

d. They are both used for energy storage in plants.

e. They are both structural components of the plant cell wall.

___ 66. Hydrolysis is involved in which of the following?

a. formation of starch

b. hydrogen bond formation between nucleic acids

c. peptide bond formation of proteins

d. the hydrophylic interactions of lipids

e. the digestion of maltose to glucose

___ 67. Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of the following is an exception to the above statement?

a. a steroid

b. a cellulose

c. DNA

d. an enzyme

e. a contractile protein

___ 68. At which level of protein structure are interactions between R-groups most important?

a. primary

b. secondary

c. tertiary

d. quaternary

e. They are equally important at all levels

___ 69. What maintains the secondary structure of a protein?

a. peptide bonds

b. hydrogen bonds

c. disulfide bridges

d. ionic bonds

e. electrostatic charges

___ 70. Condensation synthesis reactions are used in forming which of the following

compounds?

a. triglycerides

b. polysaccharides

c. proteins

d. only triglycerides and proteins are correct

e. triglycerides, polysaccharides, and proteins

___ 71.Which of the following is true concerning saturated fatty acids?

a. They have double bonds between the carbon atoms of the fatty acids.

b. They have a higher ratio of hydrogen to carbon than unsaturated fatty acids.

c. They are usually liquid at room temperature.

d. They are usually produced by plants.

e. All of these are true.

___ 72.At which bond in Figure 5.4 would water need to be added to achieve hydrolysis of the

dipeptide shown, back to its component amino acids?

a. 1

b. 2

c. 3

d. 4

e. 5

___ 73. Altering which of the following levels of structural organizations of a protein could

alter the function of an enzyme?

a. primary

b. secondary

c. tertiary

d. only primary tertiary are correct

e. primary, secondary, and tertiary

___ 74. The structural feature that allows the DNA to replicate itself is the

a. sugar-phosphate backbone

b. complimentary pairing of the bases

c. phosphodiester bonding of the helices

d. twisting of the molecules to form an alpha helix

e. three part structure of the nucleotides

___ 75. If one strand of a DNA molecule has the sequence of bases 5’ –ATTGCA -3’, the other strand would have the sequence

a. 3’ –TAACGT -5’

b. 3’ –TCCCGT -5’

c. 3’ –TUUCGU -5’

d. 3’ –TAAGCT -5’

e. 3’ –TUUGCU -5’

___ 76. Which of the following would yield the most energy per gram when oxidized?

a. starch

b. glycogen

c. fat

d. protein

e. monosaccharides

___ 77. All of the follwing molecules are proteins EXCEPT

a. hemoglobin

b. antibodies

c. collagen

d. enzymes

e. DNA

___ 78. All of the following bases are found in DNA EXCEPT

a. thymine

b. adenine

c. uracil

d. guanine

e. cytosine

___ 79. Which of the following descriptions best first the class of molecules known asnucleotides?

a. a nitrogen base and a phosphate group

b. a nitrogen bas and a five-carbon group

c. a nitrogen base, a phosphate group, and a five-carbon sugar

d. a five-carbon sugar and adenine or uracil

e. a five-carbon sugar and purine

___ 80. The tertiary structure of a protein is the

a. bonding together of several polypeptide chains by weak bonds

b. order in which amino acids are joined in a peptide chain

c. bonding of two amino acids together to from a dipeptide

d. folding of a peptide chain into an alpha helix

e. folding of the alpha helix

___ 81. Which of the following illustrates hydrolysis?

a. the reaction of two monosaccharides to from a disaccharide with the release of water

b. the synthesis of two amino acids to form a dipeptide with the utilization of water

c. the reaction of a fat to form glycerol ad fatty acids with the release of water

d. the reaction of a fat to form glycerol and fatty acids with the utilization of water

e. the synthesis of a nucleotide from a phosphate , a ribose sugar, and a nitrogen base with the production of a molecule of water

___ 82. What is a common feature of both starch and glycogen?

a. Both form microfibrils that give support to connective tissue fibers.

b. Both contain repeated monomers of glucose and galactose.

c. They are important structural components of plant cell walls.

d. They are polymers of glucose.

e. They are water-soluble disaccharides.

------

Refer to Figure 5.6 (based on the molecules illustrated) to answer the following questions(s).

___ 83. An amino acid.

a. 1

b. 2

c. 3

d. 4

e. 5

___ 84. A structural component of cell membranes.

a. 1

b. 2

c. 3

d. 4

e. 5

___ 85.Polysaccharides, lipids, and proteins are similar in that they

a. are synthesized from monomers by the process of hydrolysis.

b. are synthesized from monomers by the process of dehydration synthesis.

c. are synthesized by peptide bonding between amino acids.

d. are decomposed into their subunits by the process of dehydration synthesis.