Basic Understanding of Peptides
Every biological thing in the world is made up of proteins, from microscopic bacteria to human beings. Proteins are made up of long chain of amino acids performing a vast array of functions.
Amino acids are the building blocks of proteins which are linked together by peptide bonds making Peptides, in other words short chains of amino-acids linked together by peptide bonds are called Peptides and the chain of long and unbranched peptides forms polypeptides. But not every polypeptide forms a protein.
Difference between peptide and proteins
Proteins are peptides/polypeptides that arranged in a such a manner so that it can perform a biological function and are basically distinguished from the peptides based on their size, which is relative in nature. Some polypeptides can be considered as proteins whereas some smaller proteins are considered as peptides.
Classification of peptides based on their size
The peptide bond is formed when the carboxyl group of one amino acid joins to the amine group of another.
- Dipeptides: Consisting of two amino acids joined by a single peptide bond
- Tripeptide: Consisting of three amino acids joined by two peptide bond
- Tetrapeptide: Consisting of four amino acids joined by three peptide bond
- Oligopeptide: Consisting up to 20 amino acids
Classification of peptides in to classes based on their production
- Ribosomal peptides
- Milk peptides
- Peptide fragments
Importance of peptides in human biological activity
Peptides form a huge part of the biological signaling mechanism. Peptides are the regulators and they carry information to the cell to perform various biological functions. The cell receptors send signals to which the peptide responds and then the signal is transmitted to the DNA in the cell via membrane receptor which conducts the information.
Importance of peptides in Molecular Biology
- Generation of anti-bodies
- Helps in identification of proteins
- Helps in studying regulation of proteins and their expressions