Multiple choice

Which of the following compounds helps in digesting vitamin B12 non-destructively?

  1. Cubilin

  2. Transcobalamin-1

  3. Transcobalamin-2

  4. Transcobalamin-3

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Transcobalamin-1, also known as haptocorrin, is present in saliva. It strongly binds and protects B12 molecules from stomach acids as they enter the stomach. After B12-haptocorrin complexes pass from the stomach via the pylorus to the duodenum, pancreatic proteases cleave haptocorrin from B12 molecules.