Question

What is peptide linkage? How is dipeptide formed?

Answer 1

Hint: The peptide linkage or also known as peptide bonds are studied under the chemistry of proteins and dipeptide bonds consist of one peptide linkage.

Complete answer:
(a) If we go through the type of peptide bond, a peptide bond is a polar covalent bond which is formed in between two amino acids. And the amino acids, are organic groups which are made up of basic group $$\left(-N{H}_2\right)$$ and the acid group $$\left(-COOH\right)$$ with an alkyl chain and these are unique to each amino acid used for making proteins.
A peptide bond is formed when the carboxyl group of one molecule reacts with the amino group of the other molecule $$\left(CO-NH\right)$$. This is a condensation reaction or specifically we can say it’s a dehydration synthesis reaction (release of water molecule). Living organisms use peptide bonds to form long chains of amino acids, known as proteins.
(b) If we talk about dipeptides, these are short proteins made of only two amino acids linked together by a peptide linkage. Dipeptides can be formed by the dehydration process. During this process, a water molecule is removed in order to synthesize the dipeptides. For example if we take two amino acids they are joined together by dehydration synthesis, where a water molecule is released to form a dipeptide bond.

Additional Information: Proteins are large coiled molecules present inside the cells which have various cellular functions such as formation of enzymes, hormones, building antibodies and also serve as transport substances. All protein molecules are made of building blocks called amino acids.

Note: We have to keep in mind that dipeptide is not the type of peptide bond it actually involves one peptide linkage to join two amino acids which make proteins. There are 21 different amino acids which are little different from each other but with a similar backbone.