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Hydrogen Bonding
Name: Peter
Status: student
Grade: N/A
Location: RI
Country: N/A
Date: November 2006
Question:
What kinds of substances besides water can be
involved in hydrogen bonding?
Replies:
Since hydrogen bonding happens when a hydrogen is shared between
electronegative atoms such as oxygen or nitrogen, it has important
implications in many molecules other than water. Examples are in molecules
that are very important in your body. In the structure of DNA, hydrogen
bonds between the single strands of DNA are crucial in stabilizing the
structure of the double helix, which in turn makes DNA such a stable and
useful molecule.
You can see the hydrogen bonding between the DNA bases here:
http://en.wikipedia.org/wiki/Base_pair
Also, hydrogen bonds are very important in proteins as well. Certain side
chains which are found in proteins have hydrogen bond donor and acceptor
groups (donating a hydrogen or accepting a hydrogen through a lone pair),
and these interactions are also important in stabilizing an active structure
for the protein, as well as in the function of many proteins, such as serine
proteases, which help you break down and digest protein in food.
If you are interested, the mechanism for how these proteins work is shown at:
http://www.bmb.uga.edu/8010/moremen/weblinks/WebSerineProteases/SerProt.html
Hope that helps,
Ethan Greenblatt
Stanford Department of Chemistry
Hydrogen is the only element that acts significantly as an electron
"acceptor" in hydrogen bonding. However, many more
elements, especially those with "lone pairs" in their outermost
orbitals -- typically groups 15, 16, 17 -- are able to provide
electrons to form hydrogen bonds.
Vince Calder
Peter,
Way too many substances besides water can hydrogen bond to even
begin listing here. In general, any substance with a Lewis acidic
or Lewis basic site can hydrogen bond. Hydrogen cation transfer,
i.e. proton transfer is the essence of acid/base
chemistry. Hydrogen bonding is basically an acid/base reaction with
an equilibrium that is close to 50/50 so as to no involve the
complete transfer of the proton. Note that only one of the two or
more molecules interacting actually needs to have an acidic proton,
the other(s) need to have a Lewis basic site such as the oxygen of a
carbonyl, nitrogen, sulfur, phosphorus and many transition metals
such as palladium, titanium and many more. I am naming specific
atoms or groups of atoms, so many molecules that contain these atoms
may have the ability to hydrogen bond.
Matt Voss
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Update: June 2012
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