What is a peptide bond and what is the difference between a peptide bond and a peptide chain

A peptide bond is an amide bond formed by the dehydration and condensation of the carboxyl group of an amino acid and the amino group of an amino acid, i.e., -co-nh-. Amino acids are linked by peptide bonds to form polypeptide chains. It is the main covalent bond in the protein molecule, and its properties are relatively stable.

Although it is a single bond, it has the property of a partial double bond, which is difficult to rotate freely and has a certain rigidity, so the formation of the peptide bond plane includes the spatial position of C O, N H and 2 C at both ends of the peptide bond in a relatively close plane, and the side chain R of the adjacent two amino acids forms a trans configuration, thus forming a complex spatial structure of peptide bond and peptide chain.

The product formed by the linkage of amino acids through peptide bonds is called a peptide. The simplest peptides are peptides formed by two amino acid residues and are called dipeptides. Since the amino acids in the peptide are no longer free amino acids, they are called amino acid residues.

A polypeptide chain contains a free amino group at one end and a free carboxyl group at the other end. Therefore, in general, the number of peptide bonds formed in the peptide chain is one less than the number of amino acid molecules. For every two molecules of amino acids, the dehydration and condensation reaction into a peptide bond loses one water molecule, and the number of peptide bonds is equal to the number of water molecules lost is equal to the number of amino acids minus the number of peptide chains formed.

The chemical bond formed after the dehydration and condensation of two amino acid amino and carboxyl groups to form a peptide chain is simply —cooh+—NH3=—CO—NH2—.

Meaning of peptide chain and peptide bond:

Peptide chain: It is a chain-like structure formed by multiple amino acids linked together. It is one of the chemical substances, and amino acids are dehydrated by carboxyl and amino groups and condensed to form a product that presents a one-dimensional stretch form.

Peptide bonds: refers to the chemical bonds that connect amino acids to each other to form proteins.

The relationship between the two:

A peptide chain is formed by a number of amino acids linearly linked by peptide bonds. To use an analogy, a row of people holding hands together forms a human chain, each of them is like an amino acid, and when the hands of the two of us are connected together, it is like a peptide bond.

Therefore, the relationship between the two can be elaborated as follows: every two amino acids are connected to each other to form a peptide bond, and a chain structure containing multiple peptide bonds formed by the interconnection of multiple amino acids is called a peptide chain.

The peptide bond is willAmino acidsIt is formed by the dehydration and condensation of amino and carboxyl groups between moleculesChemical bonds, because the condensation product is called a peptide, it is called a peptide bond. A peptide bond refers to the carbonyl group in an amide group.

The lone pairs on the nitrogen atom in the adjacent c-n bond together form a three-center, four-electron delocalized bond.

The peptide bond is in a trans configuration. Since peptide bonds cannot rotate freely, cis-trans isomerism can occur in the plane of peptide bonds.

phenomenon, O and H or two C's connected to a C-N bond. The atoms are generally in a more stable trans configuration.

1.The lone pair of electrons on the nitrogen atom has a distinct conjugation effect with the carbonyl group.

2.The bond length of the C—N bond in the peptide bond is longer than the C=N bond and shorter than the adjacent C-N single bond. The C-N bond in the peptide bond has a partial double bond nature and cannot rotate freely.

3.The four atoms that make up the peptide bond are in the same plane.

4.In most cases, peptide bonds exist in a trans structure.

Peptide chainsThe relationship with peptide bonds is a tandem relationship. The peptide bond is on the peptide chain, and the peptide bond makes up the peptide chain.

The peptide chain is made up of multiple amino acids.

A chain-like structure formed by being connected to each other. Belonging to one of the chemical substances, amino acids pass through the carboxyl group.

After dehydration with amino groups, it is condensed to form a product that presents a one-dimensional stretch form. Peptide bonds refer to the chemical bonds that connect individual amino acids to each other when amino acids are linked to each other to form proteins.

Introduction to peptide chains

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One, but dipeptides can also have two peptide bonds, such as cyclic dipeptides. Dipeptide is twoPeptidesThe simplest peptide consists of a moleculeAmino acidsThe carboxyl group and another molecule of ammonia shed carry the amino group of the base acid to form by dehydration and condensationAmide bonds(i.e., co-nh-) of a protein fragment or substance.

A compound formed by the condensation of two amino acid molecules is called a dipeptide, and in a broad sense, a dipeptide includes a chain dipeptide and a cyclic dipeptide. For example, propylglutamate dipeptide is made from L-alanine.

and L-glutamic acid condensation to form a dipeptide.

Carnosine is made up of -alanine and L-histidine.

A dipeptide composed of two amino acids. Cyclic (histidine-proline) dipeptide can be hydrolyzed from corn protein, and is a cyclic dipeptide formed by the blind lurking of L-histidine chain and the cyclization of L-proline.

As composed of a glycine containing a free-carboxyl group.

A dipeptide consisting of a residue and an alanine residue containing a free-amino group is called glycylalanine.

The above content reference: 360 Encyclopedia - Dishen Late Peptide.

In fact, the other name of the peptide bond is the amide bond. An amide bond is a negatively charged functional group. In organic chemistry, the amide bond is -co-nh-, where carbon and oxygen form double bonds and nitrogen and hydrogen form single bonds.

The differences between amide bond peptide bonds are:

1. The range is different: peptide bonds are all amide bonds, and amide bonds include peptide bonds but are not equivalent to peptide bonds, and the range referred to by amide bonds is larger than that of peptide bonds.

2. In biochemistry, amide bond refers to peptide bond, which is formed by the dehydration of the amino group of one molecule of amino acids and the carboxyl group of another molecule of amino acids. However, at least 2 or more amino acids are required to form peptide bonds, and only the amide bonds in dipeptides and polypeptides are called peptide bonds.

For compounds containing amino and carboxyl groups, the conditions for the condensation reaction are catalysts by the following: the carboxyl group removes the hydroxyl group, and the amine group dehydrogenates the atom to form a peptide bond.

The way in which amino acid molecules are bound is by the combination of the carboxyl group (-COOH) of one amino acid molecule and the amino group (-NH2) of another amino acid molecule, and at the same time a molecule of water is removed, which is called dehydration condensation. The chemical bond (—nh—co—) that connects two amino acid molecules is called a peptide bond. The hydrogen in the water molecules produced in it comes from amino and carboxyl groups.

By analogy, compounds that contain multiple peptide bonds are formed by the condensation of multiple amino acid molecules and are called polypeptides. Polypeptides usually have a chain-like structure and are called peptide chain jujube mengbu. Peptide chains can coil and fold to form protein molecules with a certain spatial structure.

Many protein molecules contain several peptide chains that are bound together by a chemical bond. These peptide bonds are not straight and are not in the same plane, forming a more complex spatial structure. For example, insulin is a protein that contains two peptide chains.

The chemical bond that connects two amino acid molecules is called a peptide bond. A compound made by the condensation of two amino acid molecules, called a dipeptide (containing a peptide bond). By analogy, compounds that are formed by the condensation of multiple amino acid molecules and contain multiple peptide bonds are called polypeptides.

In the cell, the number of each amino acid is in the thousands, and when the amino acid forms the peptide chain, the arrangement of different kinds of amino acids is ever-changing, and the coiling, folding mode and spatial structure of the peptide chain are very different, so the structure of protein molecules is extremely diverse. This is the reason why there are so many types of proteins in cells.