Chapter Chapter 3: The Molecules of Cells
 
Pre-Lab
 

1 .       The large diversity of shapes of biological molecules is possible because of the extensive presence of _____. (3.1) [Hint]

 carbon
 oxygen
 hydrogen
 nitrogen
 sulfur
2 .       Variations in the properties of different organic molecules are most closely associated with _____. (3.2) [Hint]

 the number of carbon atoms comprising the molecule's skeleton
 the presence or absence of double bonds
 the presence or absence of functional groups
 the orientation of the carbon skeleton, as either ringed or linear
 the number of asymmetric carbon atoms present
3 .       Dehydration synthesis (or condensation synthesis) is the process in which ___________. (3.3) [Hint]

 water molecules are attracted to each other
 water molecules are used as a source of raw material to break down polymers to monomers.
 water molecules are formed in the formation of polymers from monomers.
 water molecules are attracted to each other and water molecules are formed in the formation of polymers from monomers.
 None of these choices is correct.
4 .       What is the main sugar used by cells for energy? (3.4) [Hint]

 any polysaccharide
 aspartame
 sucrose
 glucose
 saccharin
5 .       Glucose plus fructose forms a disaccharide called _____. (3.5) [Hint]

 maltose
 sucrose
 starch
 amino acid
 cellulose
6 .       Plant cell walls consist mainly of _____. (3.7) [Hint]

 chitin
 cellulose
 peptidoglycan
 chlorophyll
 none of the above
7 .       The characteristic that all lipids have in common is that _____. (3.8) [Hint]

 they are all made of fatty acids and glycerol
 they all contain nitrogen
 none of them is very high in energy content
 they are all acidic when mixed with water
 none of them dissolves in water
8 .       In some places a polypeptide may coil in a helix or fold back on itself as a pleated sheet. This is called _____, and the coils or folds are held in place by _____. (3.14) [Hint]

 tertiary structure ... hydrogen bonds
 primary structure ... covalent bonds
 secondary structure ... peptide bonds
 tertiary structure ... covalent bonds
 secondary structure ... hydrogen bonds
9 .       A hydrophobic amino acid R group would be found where in a protein? (3.14) [Hint]

 forming a peptide bond with the next amino acid in the chain
 on the outside of the folded chain, in the water
 on the inside of the folded chain, away from water
 forming hydrogen bonds with other R groups
 only at one end of a protein chain
10 .       The building blocks of nucleic acid molecules are called _____. (3.16) [Hint]

 polysaccharides
 amino acids
 fatty acids
 nucleotides
 DNA and RNA