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Layman's introduction to chirality in chemistry. Originally a lecture to sixth formers and high school students.
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Chemistrythrough the looking glass
Gareth J RowlandsMassey University
ORA LAYMAN`S
GUIDE to
WHY MOLECULES
HANDEDLEFT or RIGHT
CANBE
or
FOR HARDCORE
CHEMISTRY see...
http://www.massey.ac.nz/~gjrowlan/teaching.html
LECTURE NOTES
AVAILABLE FROM:
HERE GOES...
C. S. Lewis“Through the Looking-Glass, and
What Alice Found There”“”
“”“How would you like to live in Looking-glass House,
Kitty? I wonder if they'd give you milk, there?
Perhaps Looking-glass milk isn't good to drink...
©American McGee’s Alice - Electronic Arts
from PetLvr.com
PROBABLY NOT GOOD FOR KITTY
O
OHOH
O
O
HO
HO
OHOH
HO
OH
looking-glassmilk
O
OHHO
O
O
OH
OH
HO OH
OH
HO
lactosemilk sugar
THESE MOLECULESARE DIFFERENT
O
OHHO
O
O
OH
OH
HO OH
OH
HO
lactosemilk sugar
BODIES
ACCEPT ONEwill only
OUR
β-galactosidase
why?
©Renaissance Pictures
NORMALLY
©Renaissance Pictures
MIRROR IMAGES
©Renaissance Pictures
AREIDENTICALARE
BUT
©Renaissance Pictures
SOMETIMES
©Renaissance Pictures
THEY ARE
©Renaissance Pictures
DIFFERENT!
©Renaissance Pictures
DIFFERENT!
Buy “If Chins Could Kill, Confessions of a “B” Movie Actor” by
Bruce Campbell
©Marvel/Sony/Activision
2 MIRRORIMAGES
LOOK...SAME...
THAT
THE
©Marvel/Sony
DIFFERENTbutare
..ARE...
chiral
WHAT DOES
MEAN?THIS
REAL WORLDATTHE
LETS LOOK
OBJECTSARE 3D
EVERYOBJECT
HAS...
AMIRRORIMAGE
IF THE MIRROR IMAGES
IDENTICAL...ARE
THEY CAN...
OCCUPY THE...
SAME SPACE
THEY ARE
SUPERPOSABLE
achiral
IDENITCAL MIRROR IMAGES ARE
QUICKENGLISHLESSON
SUPERPOSABLEAND
the SAME
SUPERIMPOSABLEare NOT
.EXAMPLESOF
achiralOBJECTS...
TENNISRACKET
without writing
COFFEECUP
without writing
SPOON
SOCKS
BUT
SOME MIRROR IMAGES
DIFFERENTARE
© 2005 Krzysztof P. Jasiutowicz
SOME MIRROR IMAGES
DIFFERENTARE
THEY ARE
NON-SUPERPOSABLE
THEY ARE
NON-SUPERPOSABLE
THEY ARE
NON-SUPERPOSABLE
THEY ARE
NON-SUPERPOSABLE
DOES NOTMATTER
OR TURN
HOW YOU TWIST
THEYNEVER
SPACE
OCCUPY THE SAMETHE
THEYNEVER
SPACE
OCCUPY THE SAMETHE
THEY ARE
NON-SUPERPOSABLE
chiral
SUCH OBJECTS ARE
.EXAMPLESOF
chiral..OBJECTS...
HANDED
GOLF CLUBS
LEFT orRIGHT
CORK SCREW
different...
©M@nuDia @ Flickr
.....FOOTEDLEFT orRIGHT
SHOES
chirality
NATUREIN
©Jeanne Roe @ flickr
BINDWEED
CLOCKWISEanti-
©red betty black@Flickr
HONEYSUCKLECLOCKWISE
©red betty black@Flickr
TRYRACING 2
HONEYSUCKLEVINES
TWISTED inOPPOSITE
DIRECTIONS
photograph: Willi Rolfes SNAIL SHELLS
photograph: Willi Rolfes
RIGHT HANDEDSNAILS
ONLY MATEWITH
RIGHT HANDEDSNAILS
MOLECULESCAN BE
achiral
HO
HWATER
N
N N
N
O
CH3O
H3CCH3
CAFFEINE
MOLECULESCAN BE
chiral..
CC
CH3
H NH2HO
O
AMINO ACIDS(S)-(L)-ALANINE
ENZYMES
hexamerINSULIN
from Rensselaer Polytechnic Institute's Biological Honors Society
DNA
IMPORTANT?ISTHIS
WHY
AN achiral OBJECT
WITHINTERACT
AN achiral OBJECT
CAN BOTH...
MIRROR IMAGES
.EQUALLYWELL
PROPERTIESIDENTICAL
ARE
ASPOONINTERACTS
©Miramax Films
WITHHAND
IDENTICALLY
LEFT orRIGHT
BUT
A chiral OBJECT
A chiral OBJECT
INTERACTSDIFFERENTLY WITH EACH...
©DrStarbuck @ Flickr
MIRRORIMAGE
©DrStarbuck @ Flickr
THE LEFT SHOE
FITS THE
LEFT FOOT
ONLY
©SportsbookTM
RIGHT-HANDEDAS HE IS
WOODS
CLUBS
USES
TIGER.
RIGHT-HANDED
©SportsbookTM
USE BOTH!HE CAN PROBABLY
ALTHOUGH
MOLECULESARE THE
SAME..
AN achiral MOLECULE
EtO
H
AN achiral MOLECULE
WITHINTERACTCAN BOTH...
EtO
H
OHHO
OHO
OH
OHH
MIRROR IMAGES IDENTICALLY
OHO
OHO
O
OHH
Et Et
EtO
H
OHHO
OHO
OH
OHH
BUT
A chiral MOLECULE
OH
A chiral MOLECULE
OH
INTERACTSDIFFERENTLY WITH EACH...
MIRROR IMAGE
OH
OHHO
OHO
OH
OHH
HOOH
OH
OH
H HOO
OH
SLOW REACTION
OHHO
OH
OH
HOHO
HO
FAST REACTION
PROBLEM!
chiral..AREWE
Marrero, Mallorquí-Fernández, Guevara, García-Castellanos, Gomis-Rüth, J. Mol. Biol., 2006, 361, 506-521
.ENZYMES &PROTEINS
arechiral
Marrero et al., J. Mol. Biol., 2006, 361, 506-521 - apologies, this enzyme is involved in β-lactam resistance...so the following is not true...
N
S
O
OOH
HNR
O
penicillin
N
S
O
OOH
NH
R
O
MIRRORIMAGE...
ONLY ONE
Marrero et al., J. Mol. Biol., 2006, 361, 506-521 - apologies, this enzyme is involved in β-lactam resistance...so the following is not true...
N
S
O
OOH
NH
R
O
N
S
O
OOH
HNR
O
FITS...
ANYGOOD)
.(DOES US
IS AIMAGINE EACH HAND
MIRROR IMAGE OF © 2005 Krzysztof P. Jasiutowicz
A DRUG...
ENZYMETHE
IS A GLOVE...
ONLY ONE..
HAND FITS!
PROBLEM!
©Dreamworks / WB
........OTHER HANDMIGHT BE
THE
NO GOOD!UPTO
EXAMPLESTRIVIAL
.SMELL
CH3
HH3C
(R)-limoneneoranges©Patrick J. Lynch 2006
.SMELL
CH3
(S)-limonenelemons
HCH3
MIRRORIMAGE
...AND THE
©Patrick J. Lynch 2006
.TASTE
(R)-carvonespearmint
CH3
HCH3
O
MIRRORIMAGE
...AND THE
.TASTE
(S)-carvonecaraway
CH3
HH3C
O
©Fir0002@wikimedia commons PROBLEMTHE REAL
©Trois Têtes (TT)@Flickr
morning sickness
(R)-thalidomidecombats
NH
H
OO
N
O
ONH
H
O O
N
O
O
birth defects
(S)-thalidomidecauses
NH
HN
OH
Et
Et
OH
Ethambutoltuberculostatic (anti-TB)
NH
HN
OH
Et
Et
OH
(R,R)-enantiomercauses blindness
©Brookhaven National Laboratory
..MANY EXAMPLES
NMe2
Me
PhO
EtO
novradcough-suppressant
Me2NMe
Ph O
EtO
darvonpainkiller
..MANY EXAMPLES
NMe2
Me
PhO
EtO
novradcough-suppressant
Me2NMe
Ph O
EtO
darvonpainkiller
.see whatthey did with the names?
NMe2
Me
PhO
EtO
novradcough-suppressant
Me2NMe
Ph O
EtO
darvonpainkiller
.who saidscientists
have not gota sense
of humour?
C. S. Lewis“Through the Looking-Glass, and
What Alice Found There”“”
“”“How would you like to live in Looking-glass House,
Kitty? I wonder if they'd give you milk, there?
Perhaps Looking-glass milk isn't good to drink...
©American McGee’s Alice - Electronic Arts
from PetLvr.com
KITTY.SHOULD
DRINK IT!NOT
gareth(Dr. GJ Rowlands)
these slides were prepared whilst listening to
thanks
www.massey.ac.nz/~gjrowlan
the national
