What is the substrate for gastric juice?

Answer 1

The substrate is proteins, and the products are peptides.

Pepsin is a protease, i.e. an enzyme that catalyzes the breakdown of proteins. In humans, it is secreted by certain cells (called chief cells) in the lining of the stomach.

Specifically, pepsin breaks the peptide bonds linking amino acids in the chains found in proteins. Pepsin cannot break all peptide bonds, however. It is particularly efficient at hydrolyzing the bonds on the C-terminal side of tyrosine, phenylalanine, and tryptophan. It does not attack bonds involving glycine, alanine, or valine residues.

So you can think of pepsin as being like someone taking a pair of scissors to a long piece of string, and cutting in certain places. The result of peptic activity is shorter chains, called peptides.

These peptides are later further digested by other enzymes secreted by the pancreas and small intestine. The final result is free amino acids, which can be absorbed by the villi of the small intestine.
The substrate is proteins, and the products are peptides and amino acids.

Pepsin is a protease, i.e. an enzyme that catalyzes the breakdown of proteins. In humans, it is secreted by certain cells (called chief cells) in the lining of the stomach.

Specifically, pepsin breaks the peptide bonds linking amino acids in the chains found in proteins. Pepsin cannot break all peptide bonds, however. It is particularly efficient at hydrolyzing the bonds on the C-terminal side of tyrosine, phenylalanine, and tryptophan. It does not attack bonds involving glycine, alanine, or valine residues.

So you can think of pepsin as being like someone taking a pair of scissors to a long piece of string, and cutting in certain places. The result of peptic activity is shorter chains, called peptides.

These peptides are later further digested by other enzymes secreted by the pancreas and small intestine. The final result is free amino acids, which can be absorbed by the villi of the small intestine.

Answer 2

Chief cells in stomach secretes the enzyme Pepsinogen. Which is 'inactive' form of enzyme Pepsin. If Pepsin would have been secreted by stomach cells, then Pepsin would have 'digested' the same cells, which have produced them. Oxyntic cells present in stomach secretes strong Hydrochloric acid. (pH 2 to 3.) When this acid comes in contact with Pepsinogen, then Pepsinogen is converted to active enzyme that is Pepsin.(It is like you remove the cap of thewritingpen and then only you can write with it.) This Pepsin actively brakes the Pep-tide bond present in Proteins,( Which are polymer of Pep-tides.)which are present in food eaten by you.So the substrate for gastric juice is Proteins. Then next question arises that why this Pepsin does not 'digest' the stomach itself. Nature has got very beautiful arrangement for the same. Stomach is covered by sticky secretion made up of Mucus. Which is produced by Mucus secreting cells which are present all over the surface of stomach. Mucus has got no Pep-tide bond and so is not affected by Pepsin and so protect the stomach from attack by Pepsin.

Answer 3

Pepsin is a protease which breaks the peptide bonds linking amino acids in the chains found in proteins. Its substrate is proteins while the products are peptides.

Answer 4

The substrate for peptidase are peptides, which are basically small proteins.