What is the difference between a peptide link and an amide link

There are three types of amides in nature. While considering the basicity, amides are very weak bases in comparison to amines. Therefore, they do not show any acid-base properties in water. Furthermore, amides have a number of technological applications as a structural material. Nylons are such polyamides used in fabric, as fibers, and molds.

A peptide bond is a covalent bond which occurs between two consecutive amino acids, forming a polypeptide chain. However, it is also a type of amide bond since it occurs between the carboxylic group of one amino acid and the amino group of the second amino acid.

Any of the two amino acids linked by a peptide group is known as a dipeptide. Likewise, polypeptide chains occur due to a sequence of linear peptide bonds. However, due to the presence of a carboxylic group in one end and an amino group in the other end, the polypeptide chain has a polarity. Figure 2: Peptide Bond Formation. Generally, amino acids differ from each other according to the structure of the alkyl group.

During the formation of a peptide bond, a condensation reaction occurs between two amino acids. Here, the carboxylic acid of one amino acid reacts with the amine group of another amino acid, releasing a water molecule. The —OH group of the carboxylic acid group forms a water molecule, combining with a hydrogen from amine group.

We can abbreviate the peptide bond as —CONH- bond because the bond that forms involves these four atoms.

When two amino acids bind to each other through one peptide bond, the final product is a dipeptide. However, if several amino acids bind with each other, then an oligopeptide forms.

If a high number of amino acids binds with each other through peptide bonds, the complex molecule is a polypeptide. A peptide bond can undergo hydrolysis reactions. The hydrolysis breaks down the bond, separating the two amino acids.

Even though the process is very slow, hydrolysis may occur in the presence of water. Amide and peptide bonds are biochemical bonds. The ends of a polypeptide chain will be different because an alpha amino group is present at one end and an alpha carboxyl group present at the other. This gives the polypeptide chain polarity [4].

Jump to: navigation , search. Personal tools Log in. Namespaces Page Discussion. Views Read View source View history. This page was last modified on 6 December , at This page has been accessed 56, times.