Question

The pH of the secretions in the human stomach is unique in its extreme acidity (pH~2, upon food consumption typically). Pepsin, an amidase, is the main enzyme produced in the stomach and it begins the general digestion of proteins by hydrolyzing amide (peptide) linkage between amino acids.

A) What would happen to most other enzymes and proteins at a pH so low?

B) What types of amino acid interactions are most affected by such a low pH?

C) Which level of protein structure is this type of inetreactions?

D) Many people take plant-derived digestive enzyme supplements that appear to mimic the function of human smalll intestinal digestive enzymes. The functions of these enzymes are tested in ways similar to the lactase assay performed outside a cell or organismm. However, some of these supplements are sold to consumers without an enteric (protective) coating, sometimes even in powder form. Why might some gastroenterologists call the non-coatedd supplemnets "placebos, at best"? And explain your answer.

Answer 1

1) At low pH most other enzymes or proteins might break down or their structure might gey altered and they can be rendered uneffective.

2) pH is the measure of H+ion concentrations. Changes in pH affect the structure of enzymes by changing their charge . The H bonding holds the structure of tertiary amines together. So, when pH is changed this balance is distured. Hence, ionic amino acid interactions will be affected.

3) pH changes affect two types of bonds, hydrogen bonding and salt bridges. Hence, binary, tertiary and quternery structures of protiens are affected by pH changes.

4) placedos are drugs that do not have any theraputic effect but gives the patient a phsycological feeling that they will work and due to this the patient is healed faster. The gastroenterologists call non coated supplements placedos at best because of their similar action.