For each of the absorptive functions A–E, select the most appropriate co-factor(s) required for absorption from the list below

A. Option 5 Bile salts. Bile salts aid fat absorption by helping to emulsify the fat into very small globules which present a large surface area that can be attacked by pancreatic lipase. They then form part of the micelles that fit neatly between the microvilli of the enterocytes.

B. Option 2 Apoferritin. Apoferritin is an intracellular carrier that carries the iron molecules from the mucosal surface of the enterocytes to the inner surface where it is delivered to the carrier molecule, transferrin, in the plasma.

C. Option 1 A sodium dependent carrier system. The co-transporter molecule for glucose is called SGLT (sodium dependent glucose transporter).

D. Option 3 Vitamin D. In Vitamin D deficiency, calcium is not taken up by the intestinal mucosa. This results in weakening of the bones as in rickets and osteomalacia.

E. Option 4 Intrinsic factor. Vitamin B12 has to be complexed with intrinsic factor in gastric juice before it can be absorbed from the gut.