Question

AP Biology Mastering Biology Questions
(just for my reference)

Answer 1

Which molecule is a nucleotide?
Deoxyribose
The amino acid glycine
>ATP

Answer 2

What structural difference accounts for the functional differences between starch and cellulose?
Starch is a polymer of glucose, whereas cellulose is a polymer of fructose.
>Starch and cellulose differ in the glycosidic linkages between their glucose monomers.
Starch can be digested by animal enzymes, whereas cellulose cannot.

Answer 3

There are four levels of protein structure. These figures show primary, secondary, tertiary, and quaternary protein structure. Which level(s) of protein structure may be stabilized by covalent bonds?
None of the levels of protein structure is stabilized by covalent bonds.
Secondary level of protein structure
>Primary, tertiary and quaternary levels of protein structure

Explanation: The primary structure of a protein is the specific linear sequence of amino acids forming the protein. The amino acids are joined by covalent peptide bonds. Tertiary structure, producing the unique structure of a protein, is stabilized by interactions among the R groups on each amino acid in the protein. Tertiary structure may be stabilized by covalent bonds, called disulfide bridges, that form between the sulfhydryl groups (SH) of two cysteine monomers. Tertiary structure may also be stabilized by weaker interactions, including hydrogen bonds between polar and/or charged areas, ionic bonds between charged R groups, and hydrophobic interactions and van der Waals interactions among hydrophobic R groups. Many globular proteins are made up of several polypeptide chains called subunits stuck to each other by a variety of attractive forces but rarely by covalent bonds. Protein chemists describe this as quaternary structure.

Answer 4

These figures show the four levels of protein structure: primary, secondary, tertiary, and quaternary structure. Which level of protein structure is characteristic of some, but not all, proteins?
Tertiary level of protein structure
>Quaternary level of protein structure
Secondary level of protein structure

Explanation: Quaternary structure results from the aggregation of two or more polypeptide subunits, and not all proteins are composed of more than one polypeptide.

Answer 5

Note to self: left off on 5/25 questions