Peptide bond: Difference between revisions
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Peptide bonds (also known as amide bonds<ref>Berg,JM.Tymoczko, JL.and Stryer, L.,2007.Biochemistry. 6th Edition. New York: Sara Tenney.</ref>) are the bonds that are found between two [[Monomer|monomer units]] of [[Amino acid|amino acids in]] a [[Polypeptide|polypeptide chain]]. They are created through [[Condensation Reaction|condensation reactions]] in which a molecule of water (H<sub>2</sub>O) is removed. The water is made by combining | Peptide bonds (also known as amide bonds<ref>Berg,JM.Tymoczko, JL.and Stryer, L.,2007.Biochemistry. 6th Edition. New York: Sara Tenney.</ref>) are the bonds that are found between two [[Monomer|monomer units]] of [[Amino acid|amino acids in]] a [[Polypeptide|polypeptide chain]]. They are created through [[Condensation Reaction|condensation reactions]] in which a molecule of water (H<sub>2</sub>O) is removed. The water is made by combining a [[Hydroxyl group|hydroxyl group ]](OH) of one amino acid with an hydrogen from the [[Amino group|amino group ]](NH<sub>2</sub>). The two amino acids then become linked by a new peptide bond and is called a [[Dipeptide|dipeptide]]. Polypeptide chains are made up of amino acids linked together by these peptide bonds and this linear sequence forms the the [[Primary structure|primary sturcture of]] a [[Protein|protein]]. The formation of a peptide bond occurs during protein synthesis whereby which [[Ribosomes|ribosomes]] (consisting of one small subunit and one large subunit) translate an mRNA sequence coding for the protein during a process called [[Translation|translation]]. | ||
The peptide bond is a stable [[Covalent bonding|covalent bond]] and is said to be a rigid [[Planar|planar]] bond because it has a partial [[Double bond|double bond character]]. The evidence that shows this partial double bond character is from the length of the bond. It is 0.13 [[Angstrom]] shorter than the C-N single bond yet not as short as a double bond<ref>Voet, Voet, Pratt (2008) Principles of Biochemistry, 3rd Ed. Wiley. 127 </ref>. | The peptide bond is a stable [[Covalent bonding|covalent bond]] and is said to be a rigid [[Planar|planar]] bond because it has a partial [[Double bond|double bond character]]. The evidence that shows this partial double bond character is from the length of the bond. It is 0.13 [[Angstrom]] shorter than the C-N single bond yet not as short as a double bond<ref>Voet, Voet, Pratt (2008) Principles of Biochemistry, 3rd Ed. Wiley. 127 </ref>. | ||
Revision as of 11:40, 23 November 2018
Peptide bonds (also known as amide bonds[1]) are the bonds that are found between two monomer units of amino acids in a polypeptide chain. They are created through condensation reactions in which a molecule of water (H2O) is removed. The water is made by combining a hydroxyl group (OH) of one amino acid with an hydrogen from the amino group (NH2). The two amino acids then become linked by a new peptide bond and is called a dipeptide. Polypeptide chains are made up of amino acids linked together by these peptide bonds and this linear sequence forms the the primary sturcture of a protein. The formation of a peptide bond occurs during protein synthesis whereby which ribosomes (consisting of one small subunit and one large subunit) translate an mRNA sequence coding for the protein during a process called translation.
The peptide bond is a stable covalent bond and is said to be a rigid planar bond because it has a partial double bond character. The evidence that shows this partial double bond character is from the length of the bond. It is 0.13 Angstrom shorter than the C-N single bond yet not as short as a double bond[2].
Peptide bonds can also be easily broken by hydolysis (amide hydrolysis). This is completely the opposite to condensation, whereby water is added to the dipeptide/polypeptide and the peptide bond breaks to give its two constituent amino acids.
A peptide bond is a kind of linkage between two amino acids. It is also known as an amide bond. A peptide bond connects two amino acids, forming a dipeptide, and is associated with the loss of a water molecule. This process is called a condensation reaction. One perhaps surprising fact about peptide bonds is that they are very kinetically stable, in fact a peptide bond in a solution will last 1000 years, if no catalyst is present to disrupt it.
Many amino acids can be connected via peptide bonds, making a polypeptide. Each amino acid is then called a residue as it forms part of the polypeptide[3]. 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].
References
- ↑ Berg,JM.Tymoczko, JL.and Stryer, L.,2007.Biochemistry. 6th Edition. New York: Sara Tenney.
- ↑ Voet, Voet, Pratt (2008) Principles of Biochemistry, 3rd Ed. Wiley. 127
- ↑ Berg, Tymoczko, Stryer, Biochemistry 6th ed, W.H. Freeman and Company, 2007
- ↑ Alberts, Johnson, Lewis, Raff, Roberts, Walter. Molecular Biology of The Cell 2008, Garland Science.