Question

Which of the following substances requires the castle's intrinsic factor secreted by the stomach for absorption in the small intestine?
A. Amino Acids
B. water
C. Vitamin C
D. Vitamin B12

Answer 1

Hint: The intrinsic factor is secreted by the stomach, so it is present in the gastric juice as well as in the gastric mucous membrane. The optimum pH for its action is near about 7. Its concentration does not correlate with the amount of HCl or pepsin in the gastric juice.

Complete answer:
Castle (gastric) factors, it is named after the American physician and physiologist W. B. Castle,these are biologically active chemical compounds which stimulate haematopoiesis (i.e.formation of blood cellular components). There are two type of distinct factors: Extrinsic factor, which is much more commonly called as vitamin B-12 Intrinsic factor,it is a type of glycoprotein produced by the parietal cells of the stomach, which is necessary for the absorption of vitamin B-12 Chr. Intrinsic factor (IF), also known as gastric intrinsic factor (GIF), is a glycoprotein produced by the parietal cells of the stomach. It is necessary for the absorption of vitamin B-12 later on in the ileum of the small intestine. Without intrinsic factor, vitamin B-12 cannot be absorbed and it is excreted through the body as waste. People with endocrine-related autoimmune disorders, such as diabetes or thyroid disease, may have an increased risk of developing pernicious anemia.

Hence the correct answer is OPTION(D)

Note: Most cases result from the lack of the gastric protein called as intrinsic factor, without which vitamin B12 cannot be absorbed. The symptoms of pernicious anemia may include weakness, fatigue, an upset stomach, an abnormally rapid heartbeat (tachycardia), and/or chest pains.