EPO molecules travel in the blood and bind to specific EPO receptors on the surface of erythroid progenitor cells in the bone marrow. Explain why a specific three-dimensional shape of the EPO molecule is required to bind to these receptors.

Recombinant proteins and monoclonal antibodies are vital modern biopharmaceuticals.

State two other medical applications of genetically engineered proteins or monoclonal antibodies, excluding the direct treatment of anemia.

Unlike simpler proteins like insulin, erythropoietin requires post-translational glycosylation (the addition of sugar chains) to be biologically active. Suggest two reasons why eukaryotic host cells (such as yeast or mammalian cell lines) are used rather than bacteria for the industrial production of active recombinant human EPO.

Describe how scientists can use recombinant DNA technology to insert the human EPO gene into a plasmid vector, ready to transform host cells.

Suggest two reasons why clinicians and patients prefer using recombinant human EPO produced by host cells rather than EPO purified from human urine or animal donor serum.

Before a new recombinant therapeutic protein is approved for clinical use, the preclinical research describing its production, structure, and safety must undergo peer review. Explain why scientific research must undergo peer review before it is published or accepted by the medical community.