Rituximab is an example of a therapeutic protein that is used to treat certain types of cancers and autoimmune diseases. It is very sensitive to temperature and pH changes and is typically injected into the bloodstream of patients.
Which of the following statements would explain why therapeutic proteins, such as rituximab, cannot be taken orally?
I. The molecule would vibrate so fast once in the stomach that the intermolecular bonds would break
II. The conformation of the protein will change once in the stomach and it may become non-functional
III. The protein may become insoluble once in the stomach and form a precipitate due to the breakage of ionic bonds
IV. Conditions in the stomach will cause the hydrophobic R-groups of the protein to be exposed to the outside of the molecule