Biochemistry Practice Questions/ Grade 100%

Biochem, Additional Practice Questions Unit 2
Which kind of interaction can the following pair of amino acids form between their side chains (R-
groups)?

ANSWERS: Hydrogen bond

Which bond or interaction can the R group of this amino acid form to stabilize tertiary structure?

ANSWERS: Disulfide bond

A missense mutation resulting in a change from asparagine to leucine at a specific position on an
enzyme leads to a neurodegenerative disease.
Is there an alternate amino acid substitution of a missense mutation listed below that would
have less of an impact on the protein structure and consequently its function than the
proposed leucine substitution would?

ANSWERS: Correct! Glutamine is a polar amino acid and the amino acid asparagine is a polar
amino acid, which contain C-N, C-O, O-H or N-H bonds on the outside surface of their R
groups. The most likely replacement for a polar amino acid that would have less of an impact
on protein structure would be another polar amino acid.

Choose the answer that correctly labels the amino group, the carboxyl group, and the variable
group on the amino acid from the image:

ANSWERS: Correct! A is a variable group and can be any one of 20 different things, B is an
amine group that contains one nitrogen and three hydrogens, C is a carbonyl group consisting of
one carbon and two oxygens and, D is a hydrogen atom found attached to the central carbon
(carbon alpha).

Which characteristic correctly describes the amino acid image?

ANSWERS: Non-polar

Which of the following interactions can occur between two positively charged amino acids?
ANSWERS: None of these

What category does this amino acid belong to?

ANSWERS: Polar, charged

This amino acid is polar.

ANSWERS: False

This amino acid would prefer to interact with oil over water.

ANSWERS: False

, Which of the following best describes the nature of protein primary structure?

ANSWERS: Amino acids linked together in a specific order by peptide bonds

Which of the following statements about the different levels of protein structure is true?

ANSWERS: The interactions between the side chains of the amino acids make up the tertiary
level structure of a protein

Which type of bonding or interaction is correctly paired with a chemical or change in environment
that will disrupt/break the interaction or bond?
ANSWERS: Hydrogen bonds/ionic bonds: Change in pH

Which of the following statements about protein structure and stability is true?

ANSWERS: Which of the following statements about protein structure and stability is true?

The negatively charged amino acid, Glutamate, is replaced with the negatively charged amino
acid Aspartate. Which level of protein structure is most significantly impacted by this change?

ANSWERS: Primary structure

Which of the following pairs of amino acids are NOT likely to interact with one another to stabilize
tertiary structure?
ANSWERS: Option 4

Primary structure consists of the order of ______ in a protein. These are held together with
_______ bonds that are formed by a ________ reaction.
ANSWERS: Amino acids, peptide, dehydration


Which of the following statements describes the tertiary structure of a protein?
ANSWERS: It involves hydrogen bonding between amino acid side- chains.

What type of reaction breaks peptide bonds apart?

ANSWERS: Hydrolysis Reaction

A toddler mistakenly swallows a bathroom cleaning solution, containing a strong reducing agent.
Which interaction is most likely to be disrupted within a glycoprotein in the lining of the toddlerʼs
esophagus?

ANSWERS: Disulfide Bond

A patient presents with a fever of 110°F. Which interaction(s) would be disrupted within a neuronal
protein if the fever is not resolved quickly?
ANSWERS: Hydrophobic Interactions