Hydrogen bonds: Difference between revisions
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==Donor and Acceptor Atoms== | ==Donor and Acceptor Atoms== | ||
<table align='right' border='0' width='184' cellpadding='10' bgcolor='#d0d0d0' hspace='8'><tr><td rowspan='2'> </td><td bgcolor='#e8e8e8'> | <table align='right' border='0' width='184' cellpadding='10' bgcolor='#d0d0d0' hspace='8'><tr><td rowspan='2'> </td><td bgcolor='#e8e8e8'> | ||
[[Image:Hbond.gif]]</td></tr><tr><td bgcolor='#e8e8e8'><div style='color: white; background-color: black;'> Elements {{Template:ColorKey_Element_C}}, {{Template:ColorKey_Element_H}}, {{Template:ColorKey_Element_N}}, {{Template:ColorKey_Element_O}}.</div>A hydrogen bond between a <font color='#6565b4'><b>nitrogen donor</b></font> and an <font color='red'><b>oxygen acceptor</b></font>. Distances shown are typical for those found in proteins.</td></tr></table> | [[Image:Hbond.gif]]</td></tr><tr><td bgcolor='#e8e8e8'><div style='color: white; background-color: black;'> Elements: {{Template:ColorKey_Element_C}}, {{Template:ColorKey_Element_H}}, {{Template:ColorKey_Element_N}}, {{Template:ColorKey_Element_O}}.</div>A hydrogen bond (dotted white line) between a <font color='#6565b4'><b>nitrogen donor</b></font> and an <font color='red'><b>oxygen acceptor</b></font>. Distances shown are typical for those found in proteins.</td></tr></table> | ||
Hydrogen bonds ("hbonds") occur when a ''donor'' atom donates its covalently bonded hydrogen atom to an electronegative ''acceptor'' atom. Typical donor atoms are the oxygens in -OH (e.g. the sidechains of Ser, Thr, Tyr), HOH, and the nitrogen in -NH3+ (as in the sidechains of Lys, Arg) or -NH- (as in the main chain peptide bond, and the sidechains of Trp, His, Arg, and nucleotide bases). The lone electron pairs on these same donors can serve as hbond acceptor sites. So can those on carbonyl oxygens =O (as in the protein main chain) or nitrogens with three covalent bonds =N- (as in the sidechains of His, Trp, or in nucleotide bases). Lacking hydrogens, these latter cannot serve as donors. | Hydrogen bonds ("hbonds") are non-covalent bonds that occur when a ''donor'' atom donates its covalently bonded hydrogen atom to an electronegative ''acceptor'' atom. Typical donor atoms are the oxygens in -OH (e.g. the sidechains of Ser, Thr, Tyr), HOH, and the nitrogen in -NH3+ (as in the sidechains of Lys, Arg) or -NH- (as in the main chain peptide bond, and the sidechains of Trp, His, Arg, and nucleotide bases). The lone electron pairs on these same donors can serve as hbond acceptor sites. So can those on carbonyl oxygens =O (as in the protein main chain) or nitrogens with three covalent bonds =N- (as in the sidechains of His, Trp, or in nucleotide bases). Lacking hydrogens, these latter cannot serve as donors. | ||
==Distances and Energies== | ==Distances and Energies== | ||