Peptides and protein: enzymes, monomer, polypeptide structure, sequence of amino acid

Amino acids are sequence let , Ser-Gly-Tyr-Ala-Leu or SGYAL with a single code of amino acids sequence in the peptide. In this biopolymer process..

Peptides and protein

Hello everyone today we will discuss proteins and peptides of amino acid formation. We have already discussed amino acid structure, amino acid code, essential amino acid, and their structure. Total natural 20 amino acids, their classification of amino acids use different polarities of the molecule and solubility of amino acids. Alpha-amino acids are naturally their classification - acidic amino acid, basic amino acid, amino acid attach with OH group, amino acid attach with S group, aromatic amino acid, etc. 

Peptides and protein: enzymes, monomer, polypeptide structure, sequence of amino acid
Peptides and protein: enzymes, monomer, polypeptide structure, sequence of amino acid

In the second (second article) class of amino acids, we will discuss zwitterion and isoelectric points. We briefly discuss what the zwitterion definition is. How to form amino acids? 

What is the isoelectric point definition? What is the isoelectric point amino acid?

Now today we will discuss what is protein and peptide formation?

Protein foods:

The source of protein is natural food. Protein foods are eggs, fish, milk, beef, chicken, etc.  

Protein and amino acids

Definition of Protein

Proteins are large biomolecules or we can call them macromolecules. Proteins consist of one or more long chains of amino acid residues, which is known as the protein chain. 

Protein example: fish, eggs, chicken, beef, etc all-natural foods are resources of protein.    

Definition of Biopolymer

The monomeric amino acids are linked through an amide Bond which is given below. That means the amino group links with the carboxylic acid group. Which process is called the biopolymer?

Definition of Biopolymer| Definition of Protein| Protein and amino acids

Yes, this is the biopolymer process of amino acids. 

Using the biopolymer process the amide bond formation of peptide or protein polymer.


what is the difference between protein and peptide

Their common Protein and peptide difference is protein has Greater than amino acid monomer On the other hand peptides have less than 50 amino acid monomers.

Peptide proteins and amino acids

The protein and peptides are the same things, Protein and peptides are linked with Different types of monomer sequences of amino acid monomers. 

Peptides are linked with different types of amino acid monomers and the formation of polypeptides. Similarly different types of amino acids are linked with the amino group and acetic group( carboxylic acid) which form protein.

Amino acid peptide and protein in biology or biochemistry which are following the main pathway of biological thinking. 

Read More: Amino acids structures| 9 essential amino acids formula

Read More: Zwitterion and isoelectric point: Definition, Separation of amino acid, TLC.

Peptide bond formation

The sequence of amino acid monomers they have considered the two amino acids. One has carboxylic acid and another has an amino group that is bonded between and formed with an amide bond; this is the peptide bond formation.

Peptide bond formation
Peptide bond formation

Structure of a simple peptide

Amino acids are sequence let, Ser-Gly-Tyr-Ala-Leu or SGYAL with a single code of amino acids sequence in the peptide. In this biopolymer process, the monomers or amino acid monomers are Ser, Gly, Tyr, Ala, and Leu. In case this peptide has one Amino-terminal end and one Carboxyl terminal end. In the case of peptides, Serine has an amide terminal end and leucine has a carboxyl-terminal end.

Naming peptides: start at the N Terminus

For the naming peptides, we can use 3 letter codes for amino acids. which starts from N Terminus.

For the long-chain peptide which is called protein, they are naming one letter Code we can use. For time saving and helpful to us.


The peptide Bond characterization

In case the amide nitrogen is SP2 hybridized and they are a lone-pair is conjugated with a carbonyl group. For conjugation of carbon and nitrogen bonds, they formed double bond characters.

  • In the case of the double character of C-N Bond, the rotation is difficult. 

  • Mainly the amide group is planar. Therefore we can see the R group is on the opposite side of the plane. 

  • The different types of covalent bonds for the amino acid in protein and peptide is called disulfide linkage between two cysteine amino acid units.

  • Incase is oxidized to disulfide, and disulfide is reduced into thiols.

Two cysteine units are bonded with a disulfide bridge. Cysteine sulfide is oxidized and the formation of a disulfide bridge is one type of covalent bond. 

Peptides are classified Into two types one is straight or another is curly.

That means Peptide looks like two types of hair: one is curly hair or the other is straight. Curly hair means like chowmein. And straight hair is a straight line with disulfide Bond Linkage. 

Disulfide Bridge formation
Disulfide Bridge formation of peptide or protein

Sequencing method of peptide

Amino acid analysis in peptides

Firstly we used the amino acid analysis to find out which amino acids and how many make up the peptide. And what is the sequence of peptides?

The Terminal Residue analysis of peptides

For the terminal Residue analysis of peptides, we can use several types of methods. For N terminal analysis We can use the Sagnar method, the Dansyl chloride method, Edman degradation.

 And for C terminal analysis we can use the carboxypeptidase method.

Partial Hydrolysis

Enzymatic Hydrolysis

In case enzymatic hydrolysis is the fragmentation of the peptide. Protein enzymes are used for enzyme hydrolysis for peptide bonds broken in protein sequences of amino acids.  


Peptide Bond cleavage at Lys and Arg at C-terminal side chain. Cleavage from the basic side. For example, peptide sequences are Ala-Glu-Lys-Asp-Met. For partial hydrolysis of peptides using Trypsin, we get Ala-Glu-Lys and Asp-Met. Lys is a basic amino acid. At C terminal is Lys therefore the bond cleavage from Lys side.


Peptide Bond cleavage at Phe, Tyr, and Trp at the terminal side chain. Mainly cleavage from the aromatic side of the peptide chain

For example, the peptide sequence is Asp-Met-Trp-Glu-Arg, for partial hydrolysis of the peptide using chymotrypsin we get  Asp-Met-Trp and Glu-Arg fragmentation. In case Trp is an aromatic amino acid, since Trp side peptide bond cleavage in the peptide long chain.


Peptide bond cleavage at Leu, Asp, and Glu at N-Terminal side.

For an example of peptide bond cleavage of Asp-Met-Trp-Glu-Arg peptide sequence, using the pepsin we get Asp, Met, Try, and Glu-Arg fragmentation of peptide.

Cyanogen bromide 

It is not an enzyme. Peptide bond cleavage from Met at C- terminal side chain. 


We are trying to discuss the basic concepts of peptides and protein of amino acid sequence.

We can briefly read the concept of the peptide bond of amide and carboxylic acid in peptide sequence amino acids. We hope to better understand this type of chem_article. Thanks for reading. If you have any queries you can ask us.  


Frequently asked question

What is the difference between peptide and protein?

Ans: The difference between peptide and protein is that protein is a long-chain amino acids sequence. Peptides are small chains. Peptide and protein bond formation is exactly the same. But their size and shape are different. Peptide amino acids sequence maximum 50 amino acids are required. In the protein amino acid sequence, greater than 50 amino acids are required. Therefore protein size is comparatively larger than peptide.

What is the use of peptides?

Peptides are used for supplement resources like supplement pills, protein shakes, etc. which make strong fitness and health. The peptide is used to body fat loss, maintain body weight, increase the body muscle for bodybuilders.

Is a peptide a protein?

Ans: yes, a peptide is a protein. Lots of peptides made up a protein. The peptide is small compared to protein. They all peptides and proteins build body growth.