Deck 2: The Chemistry of the Cell

Question 1

Which of the following is FALSE regarding water's specific heat?

A)The specific heat of water is similar to most liquids.
B)Water's high specific heat has a temperature- buffering effect.
C)The specific heat of water is 1.0 calorie per gram.
D)Water gains and loses heat more slowly than most other solvents.
E)Heat applied to water must initially break a number of hydrogen bonds.

Answer 1

A

Question 2

Which of the following sequences correctly lists the hierarchical nature of cellular structures, from smallest to largest?

A)macromolecules, organic molecules, supramolecular structures, organelles, cells
B)organic molecules, supramolecular structures, macromolecules, organelles, cells
C)organic molecules, macromolecules, supramolecular structures, organelles, cells
D)organelles, organic molecules, supramolecular structures, macromolecules, cells
E)organic molecules, macromolecules, organelles, supramolecular structures, cells

Answer 2

C

Question 3

Flat rocks may be made to skip across the water. Which of the following properties of water can explain these observations?

A)Water molecules create spheres of hydration around solute molecules.
B)Water is an excellent solvent.
C)Water molecules are cohesive.
D)Water molecules are often associated via hydrogen bonds.
E)both C and D

Answer 3

E

Question 4

Which of the following is NOT true of hydrocarbons?

A)Many hydrocarbons are used in living systems.
B)Phospholipids have hydrocarbon tails.
C)Hydrocarbons are insoluble in water.
D)Only hydrogen atoms are used to complete the valence requirements of carbon.
E)Octane is a hydrocarbon.

Question 5

Biologically, which of the following is the least important characteristic of water?

A)Water is a good solvent.
B)Water molecules are polar.
C)Water typically contains isotopes of hydrogen.
D)Water has a temperature stabilizing capacity.
E)Water molecules have numerous hydrogen bonds.

Question 6

Which of the following is a unit of energy?

A)calorie
B)joule
C)mole
D)watt
E)both A and B

Question 7

Self- assembly is limited by

A)the time associated with forming solely noncovalent interactions.
B)the presence of water in the cytosol.
C)information of pre- existing structures.
D)the size of the molecule.
E)all of the above.

Question 8

Which of the following molecules is involved with assisted assembly?

A)water molecules
B)helper proteins
C)tobacco mosaic viruses
D)molecular chaperones
E)none of the above

Question 9

Why do polar substances such as NaCl dissolve so readily in water?

A)NaCl is a very dry powder, and the water is able to soak into the salt.
B)The sodium ions repel the negative end of the water molecule.
C)Spheres of hydration form between the water and the ions.
D)The charged ends of the water molecules are able to surround the oppositely charged salt ion.
E)both C and D

Question 10

Why is a selectively permeable membrane so important to living things?

A)The membrane may absorb several times its weight in cholesterol.
B)It provides a good barrier between the inside and outside of the cell.
C)Proteins will avoid a selectively permeable membrane.
D)It allows cells to attach to adjacent tissues.
E)all of the above

Question 11

Ribose has five carbon atoms, of which three are asymmetric. What is the maximum number of stereoisomers that may exist for ribose?

A)8
B)10
C)2
D)6
E)4

Question 12

An enzyme synthesized in the laboratory is found to have little activity when compared to the enzyme extracted from cell culture. Both enzymes were examined and have identical amino acid composition. What is the best explanation for the lack of activity of the synthesized enzyme?

A)The synthetic enzyme was not made of amino acids.
B)Denaturation of the synthesized enzyme was not complete.
C)The synthesized enzyme was not folded correctly because molecular chaperones were not present.
D)The ATP required for self- assembly was present in the cell extract but not in the laboratory synthesis.
E)The van der Waals radius was altered during laboratory synthesis.

Question 13

Which of the following is NOT soluble in water?

A)amino acids
B)nucleic acids
C)lipids
D)sugars
E)disaccharides

Question 14

Which of the following is NOT true of the polymerization of macromolecules?

A)Water is added to join the monomers of the macromolecules.
B)The polymer chain usually has two different ends.
C)Macromolecules are synthesized by the stepwise addition of monomers.
D)Often the energy needed for polymerization is supplied by ATP.
E)A monomer is usually activated by the coupling of the monomer to a carrier.

Question 15

Which of the following was NOT considered part of the "alphabet of biochemistry" by George Wald?

A)seven proteins
B)the 20 amino acids
C)the 5 nucleotide bases
D)two sugars
E)three lipids

Question 16

The cell membrane can be described most accurately as

A)impermeable to all polar molecules.
B)permeable to only larger molecules.
C)permeable to most small molecules, but impermeable to larger ones.
D)permeable to all molecules.
E)permeable to some molecules and impermeable to others.

Question 17

The cell membrane can be described most accurately as

A)permeable to some molecules and impermeable to others.
B)permeable to all molecules.
C)permeable to only larger molecules.
D)permeable to all small molecules and ions, but impermeable to larger ones.
E)impermeable to all polar molecules.

Question 18

Which of the following is NOT a fundamental property of carbon?

A)Carbon- containing molecules form stereoisomers.
B)Carbon- containing molecules are diverse.
C)Carbon has a valence of 4.
D)Carbon atoms are most likely to form ionic bonds with one another.
E)Carbon- containing molecules are stable.

Question 19

Which of the following is NOT a structural polysaccharide?

A)glycogen
B)chitin
C)peptidoglycan
D)cellulose
E)All of the above are structural polysaccharides.

Question 20

The polymerization of different types of macromolecules is similar in many respects. Which of the following principles below is LEAST likely to be common to all methods of polymerization of macromolecules?

A)As monomers are added to the polymer, water is removed from the macromolecule.
B)To be added to the polymer, the monomer must be activated.
C)Macromolecules are synthesized by the addition of monomers.
D)Polymerization is passive, requiring little ATP.
E)The polymer is directional.

Question 21

Carbon can form covalent bonds.

A)single and double
B)triple
C)single
D)single, double, and triple
E)double

Question 22

Because membranes usually are not permeable to polysaccharides, nucleic acids, and proteins, how are cells able to incorporate these molecules?

A)These macromolecules are only incorporated into structures outside the membrane.
B)Macromolecules are broken down extracellularly, and their subunits diffuse through the membrane.
C)Macromolecules are digested extracellularly, and their subunits move through transport proteins.
D)Macromolecules are transported via endocytosis and digested within the cell.
E)both C and D

Question 23

What branch of chemistry deals specifically with living systems?

A)inorganic chemistry
B)organic chemistry
C)biochemistry
D)biological chemistry
E)both C and D

Question 24

Which of the following is NOT a possible noncovalent interaction?

A)van der Waals interactions
B)polar covalent bonding
C)ionic bonding
D)hydrogen bonding
E)hydrophobic interactions

Question 25

and groups are negatively charged functional groups of carbon, whereas the group is a positively charged functional group.

Question 26

Which of the following biological polymers is mismatched with its monomer?

A)DNA - nucleotide
B)chitin - monosaccharide
C)enzyme - amino acid
D)cellulose - amino acid
E)protein - amino acid

Question 27

While synthesizing a new blue pigment, a chemist notices that the new compound congregates between an aqueous (water)environment and a hydrophobic environment. When added to a mixture of oil and water, the pigment creates a blue ring around the droplets of oil. Which of the following statements best describes this new pigment?

A)The pigment is a polar molecule and is forming hydrogen bonds with both the water and oil molecules.
B)The pigment is neither polar or nonpolar, but is apolar.
C)The pigment is probably hydrophobic and is attempting to bond with the oil.
D)The pigment is hydrophilic and will not form hydrophobic bonds with the oil.
E)The pigment is amphipathic, having polar and nonpolar regions.

Question 28

Which of the following is true of an asymmetric carbon atom?

A)Asymmetric carbon atoms create stereoisomers.
B)A carbon with hydrogens attached at two locations is usually asymmetric.
C)Molecules may have only one asymmetric carbon atom.
D)Methane has an asymmetric carbon.
E)Only amino acids have asymmetric carbon atoms.

Question 29

Due to the directionality of polymer synthesis, proteins have a distinct _ and
end.

Question 30

A hypothetical automobile has 100 parts that are to be assembled by four workers. During the car's assembly, each worker constructs 25 parts individually, and then the four resulting components are assembled together. The manner in which the car was assembled is much like which cellular strategy?

A)renaturation
B)self- assembly
C)assisted self- assembly
D)hierarchical assembly
E)electrostatic assembly

Question 31

The moon lacks life and varies dramatically in temperature. If we could keep a layer of water spread on the surface of the moon, what effect would it have?

A)The temperatures would drop to the lower extremes.
B)Physical conditions would remain the same.
C)Life would be possible, but it would have to withstand these extremes in temperature.
D)Water would absorb and hold heat and moderate the temperature extremes.
E)Because water has a high heat of vaporization, the temperatures would rise to the upper extremes.

Question 32

The hierarchical nature of cellular structure is accurately illustrated in which of the following lists of substances (small to large)?

A)nucleotides, nucleus, DNA, chromosome, cell
B)cellulose, glucose, cell wall, cell
C)protein, membrane, amino acids, chloroplast, cell
D)nucleotides, chromosome, DNA, nucleus, cell
E)nucleotides, DNA, chromosome, nucleus, cell

Question 33

Polymers are synthesized by reactions and broken down into their constituent monomers by reactions.

Question 34

In order to facilitate polymerization, monomers must be .

Question 35

The purpose of reducing and oxidizing agents in denaturation and renaturation is the breaking and reforming of the bond.

Question 36

carbon atoms allow for the formation of , which are mirror images of each other.