Medical Biology_Mock Test #3

Which of the following statements about polysaccharides is incorrect?

• Polysaccharides can have branched or unbranched structures.
• Polysaccharides can contain more than one type of monosaccharide.
• Polysaccharide chain length can never exceed one hundred units.
• no correct response
• All response is correct

Which of the following statements about polysaccharides is incorrect?

• An alternate designation for a polysaccharide is glycan.
• Polysaccharides almost always have a sweet taste.
• Polysaccharides have limited solubility in water.
• no correct response
• All response is correct

Which of the following levels of protein structure may be affected by hydrogen bonding?

• primary and secondary
• primary and tertiary
• secondary, tertiary, and quaternary
• primary, secondary, and tertiary
• primary, secondary, tertiary, and quaternary

Which of the following associations between R groups are the strongest?

• hydrophobic interactions
• hydrogen bonds
• ionic bonds
• peptide bonds
• disulfide bridges

The α helix and β pleated sheet represent which level of protein structure?

• Primary structure
• Pentiary structure
• Secondary structure
• Tertiary structure
• Quaternary structure

The "primary structure" of a protein refers to __________.

• the weak aggregation of two or more polypeptide chains into one functional macromolecule
• the sequence of amino acids along a polypeptide chain
• interactions among the side chains or R groups of the amino acids
• coiling due to hydrogen bonding between amino acids
• the α helix or β pleated sheets

A polar neutral amino acid is an amino acid that contains _____ amino group, _____ carboxyl group, and a side chain that is polar but neutral.

• one … one
• one … two
• two … one
• two … two
• No response is correct

Some lipids are formed when fatty acids are linked to glycerol. These subunits are linked together by __________.

• glycosidic linkages
• ester linkages
• phosphodiester linkages
• ionic bonds
• peptide bonds

Which of the following lists represents the chemical components of a nucleotide?

• A series of nitrogenous bases, a nucleic acid backbone, and a hexose sugar
• A nitrogenous base, an amino acid, and a phosphate group
• A nitrogenous base, a fatty acid, and an amino acid
• A nitrogenous base, a phosphate group, and a pentose sugar
• A nitrogenous base, an amino acid, and a pentose sugar

Enzyme activity is affected by pH because __________.

• changes in pH can cause loss of cofactors from the enzyme
• high or low pH may disrupt hydrogen bonding or ionic interactions and thus change the shape of the active site
• low pH will denature all enzymes
• the binding of hydrogen ions to the enzyme absorbs energy and thus there may not be enough energy to overcome the activation energy barrier
• most substrates do not function well at high or low pH