A. It is important that the binding interactions involve a mixture of van der Waals
interactions, hydrogen bonds and ionic bonds since neurotransmitters have different
functional groups
B. The binding interactions must be of the correct nature to match the functional groups of
the neurotransmitter and the functional groups in the binding site
C. The binding interactions must be sufficiently strong that the neurotransmitter binds long
enough to have an effect, but not too strong in case the neurotransmitter remains
permanently bound
D. There must be the correct balance of hydrophilic and hydrophobic interactions to ensure
that the chemical messenger can enter a hydrophobic binding site
1.6 Which of the following statements is true regarding intracellular receptors?
A. They consist of three protein subunits
B. They contain a ligand binding site near the N-terminal end
C. They contain a binding region for DNA near the middle of the protein
D. They are activated by hydrophobic molecules which are synthesised within the cell
1.7 Which of the following amino acids is phosphorylated by a protein kinase?
A. Cysteine
B. Tyrosine
C. Phenylalanine
D. Lysine
1.8 Which of the following statements is false?
A. Desolvation is an energy expensive process which involves the removal of water from
polar functional groups prior to a drug binding to its binding site
B. Water molecules surrounding a hydrophobic region of a drug form an ordered layer of
molecules with high entropy
C. Interaction between the non-polar regions of a drug and the non-polar regions of a target
require the removal of an ordered water coat and represents a gain in binding energy due
to increased entropy
D. An increase in entropy results in a greater negative value of DG and a greater chance of
binding
1.9 Which statement best describes the relevance of an allosteric binding site to medicinal
chemistry?
A. It is more hydrophobic than normal binding sites and accepts hydrophobic drugs in
preference to hydrophilic drugs
B. A larger variety of drug structures will bind to the allosteric site than to the active site
C. Drugs can be designed based on the structure of the endogenous chemicals which bind
to allosteric sites and control enzyme activity
D. Drugs can be designed based on the transition state of the enzyme-catalysed reaction
1.10 What type of plots can be used to determine whether an enzyme inhibitor is competitive or
non-competitive?
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