Chapter 4 Test Banks

1) The element present in all organic molecules is ________. A) hydrogen B) oxygen C) carbon D) nitrogen

2) The complexity and variety of organic molecules is due to ________. A) the chemical versatility of carbon atoms B) the variety of rare elements in organic molecules C) the diverse bonding patterns of nitrogen D) their interaction with water

3) The experimental approach taken in current biological investigations presumes that ________. A) simple organic compounds can be synthesized in the laboratory from inorganic precursors, but complex organic compounds like carbohydrates and proteins can be synthesized only by living organisms B) a life force ultimately controls the activities of living organisms, and this life force cannot be studied by physical or chemical methods C) living organisms are composed of the same elements present in nonliving things, plus a few special trace elements found only in living organisms or their products D) living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena

insoulable

4) Differences among organisms are caused by differences in the ________. A) elemental composition from organism to organism B) types and relative amounts of organic molecules synthesized by each organism C) sizes of the organic molecules in each organism D) types of inorganic compounds present in each organism

nonpolar covalent

5) Stanley Miller's 1953 experiments supported the hypothesis that ________. A) life on Earth arose from simple inorganic molecules B) organic molecules can be synthesized abiotically under conditions that may have existed on early Earth C) life on Earth arose from simple organic molecules, with energy from lightning and volcanoes D) the conditions on early Earth were conducive to the origin of life

6) Miller's classic experiment demonstrated that a discharge of sparks through a mixture of gases could result in the formation of a large variety of organic compounds. Miller did not use ________ as one of the gases in his experiment. A) methane B) oxygen C) water D) ammonia

7) Which of the following is true of carbon? A) It forms only polar molecules. B) It can form a maximum of three covalent bonds with other elements. C) It is highly electronegative. D) It can form both polar and nonpolar bonds.

8) The kind and number of bonds an atom can form depends on ________. A) its atomic number B) its electron configuration C) its atomic mass D) the number of particles in its nucleus

9) Why is carbon so important in biology? A) It is a common element on Earth. B) It has very little electronegativity, making it a good electron donor. C) It bonds to only a few other elements. D) It can form a variety of carbon skeletons and host functional groups

10) How many electrons does one atom of carbon share to complete its valence shell? A) 2 B) 3 C) 4 D) 8

11) A carbon atom has 6 electrons however, its valency is 4. This is because the carbon atom ________. A) donates its 2 electrons to another atom B) shares its 2 electrons and bonds with another atom C) has 4 electrons in its first shell and 2 in the second shell D) has only 2 electrons in its first shell and 4 in the second shell

12) In an ethane (C2H6) molecule, each carbon atom is bonded to ________ hydrogen atoms. A) two B) three C) four D) six

13) A carbon atom is most likely to form what kind of bond(s) with other atoms? A) ionic B) hydrogen C) covalent D) ionic bonds, covalent bonds, and hydrogen bonds

covalent bonds

14) Why are hydrocarbons insoluble in water? A) The majority of their bonds are polar covalent carbon-to-hydrogen linkages. B) The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. C) They exhibit considerable molecular complexity and diversity. D) They are less dense than water.

polar covalent

hydrocarbons

15) Which of the following statements correctly describes cis-trans isomers? A) They have variations in arrangement around a double bond. B) They have an asymmetric carbon that makes them mirror images. C) They have the same chemical properties. D) They have different molecular formulas

cis-trans isomers

Each bond in carbon dioxide represents ________. O=C=O A) one resonating electron B) a pair of shared electrons C) two pairs of shared electrons D) a pair of protons

17) Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that ________. A) have identical chemical formulas but differ in the branching of their carbon skeletons B) are mirror images of each other C) differ in the location of their double bonds D) differ in the arrangement of atoms around their double bonds

18) What determines whether a carbon atom's covalent bonds to other atoms are in a tetrahedral configuration or a planar configuration? A) the presence or absence of bonds with oxygen atoms B) the presence or absence of double bonds between the carbon atom and other atoms C) the polarity of the covalent bonds between carbon and other atoms D) the solvent in which the organic molecule is dissolved

19) Which of the following carbon molecules does not have the bond angle of 109.5°? A) CH4 B) C2H4 C) C2H6 D) C3H8

20) Compared to a hydrocarbon chain where all the carbon atoms are linked by single bonds, a hydrocarbon chain with the same number of carbon atoms but with one or more double bonds will ________. A) be more flexible in structure B) be more constrained in structure C) be more polar D) have more hydrogen atoms

constrained

21) Organic molecules with only hydrogens and five carbon atoms cannot ________. A) have a branching carbon skeleton B) have different combinations of double bonds between carbon atoms C) have different positions of double bonds between carbon atoms D) form enantiomers

enantiomers

22) Some carbon skeletons have different numbers and locations of double bonds to ________. A) add molecular complexity and diversity that characterize living matter B) be more flexible that makes the molecule stronger C) stay in its liquid state D) increase its solubility in water

31) Which of the functional groups is not reactive but serves as a recognizable tag on the DNA molecule and alter the expression of genes in the cells. A) amino B) methyl C) carboxyl D) hydroxyl

32) A compound contains hydroxyl groups as its predominant functional group. Therefore, this compound ________. A) lacks an asymmetric carbon and is probably a fat or lipid B) should dissolve in water C) should dissolve in a nonpolar solvent D) will not form hydrogen bonds with water

33) Which two functional groups are always found in amino acids? A) carbonyl and amino groups B) carboxyl and amino groups C) amino and sulfhydryl groups D) hydroxyl and carboxyl groups

amino acids

34) Amino acids are acids because they always possess ________ as the functional group? A) amino B) carbonyl C) carboxyl D) phosphate

carboxyl

35) 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 ________. A) are structural isomers but have the same molecular formula B) are cis-trans isomers but have the same molecular formula C) have different functional groups attached to the same carbon skeleton D) are enantiomers of the same organic molecule

Ionized molecules

carboxyl group

organic acids

mercaptoethanol reduction of a disulfide bridge

thiol

energy currency of living organisms

51) Which of the following statements is true? A) ADP contains more energy than ATP. B) Following hydrolysis, ATP can give off one phosphate, whereas ADP cannot. C) ADP can have two positive charges. D) ATP can have four negative charges.

52) Which of the following molecules is a part of ATP? A) adenosine B) cytosine C) guanine D) uracil

1) Organic chemistry is currently defined as A) the study of compounds made only by living cells. B) the study of carbon compounds. C) the study of natural (as opposed to synthetic) compounds. D) the study of hydrocarbons

3) Which chemical group is most likely to be responsible for an organic molecule behaving as a base? A) hydroxyl B) carbonyl C) amino D) phosphate

4) Visualize the structural formula of each of the following hydrocarbons. Which hydrocarbon has a double bond in its carbon skeleton? A) C3H8 B) C2H6 C) C2H4 D) C2H2

6) Which action could produce a carbonyl group? A) the replacement of the -OH of a carboxyl group with hydrogen B) the addition of a thiol to a hydroxyl C) the addition of a hydroxyl to a phosphate D) the replacement of the nitrogen of an amine with oxygen