Hydrogen bonds: Difference between revisions
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<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='background-color: black;'> {{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 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 occur when a "donor" atom donates its covalently bonded hydrogen atom to an electronegative "acceptor" atom. The oxygen in -OH (e.g. Ser, Thr, Tyr), HOH, and the nitrogen in -NH3+ (as in Lys, Arg) or -NH- (as in the main chain peptide bond, Trp, His, Arg, nucleotide bases) are typical donors. The lone electron pairs on these same donors can serve as hbond acceptor sites. So can those on carbonyl oxygens =O (as in the main chain) or nitrogens with three covalent bonds =N- (as in His, Trp, or nucleotide bases). Lacking hydrogens, these latter cannot serve as donors. | Hydrogen bonds occur when a "donor" atom donates its covalently bonded hydrogen atom to an electronegative "acceptor" atom. The oxygen in -OH (e.g. Ser, Thr, Tyr), HOH, and the nitrogen in -NH3+ (as in Lys, Arg) or -NH- (as in the main chain peptide bond, Trp, His, Arg, nucleotide bases) are typical donors. The lone electron pairs on these same donors can serve as hbond acceptor sites. So can those on carbonyl oxygens =O (as in the main chain) or nitrogens with three covalent bonds =N- (as in His, Trp, or nucleotide bases). Lacking hydrogens, these latter cannot serve as donors. | ||