chemistry and living system

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chemistryand living systems123.101

chemistryanintroductionto

and...

...howitrelatestoliving

things

the study guide contains all the information you need

my lectures contain explanationand examples

but as I’m not here...

...the Prof will have to do!

my notes are available from:www.massey.ac.nz/~gjrowlan/teaching.html

Ready?

pic: Aquarium of the Pacific

Unit One Part 1: introduction

pic: Aquarium of the Pacific

Unit One Part 1: introductionthese are not random

pictures; the molecule is a potential painkiller

called epibatidine which is isolated from poison

dart frogs...

why do we need organic chemistry?

why do we need organic chemistry?

...because its fun??

why do we need organic chemistry?

...it keeps me in a job?Or...

i f we want to understand living systems...

w e n e e d t o understand the individual organs...

...to understand organs, we have to understand cells...

...and still we have to get smaller and

smaller...

N

NN

N

Me

Me

MeHO2C(H2C)2

Me

HO2C(H2C)2

Fe

...and to do this we must understand the molecules that make up these systems

haem

but we don't need to get carried away...

Image Credit: NIST/University of Colorado

...lets stop with atoms & electrons!And none of this maths malarkey.

simple chemical principles control

biology

isomers and the v isua l cascade

Me Me

Me Me

Me

NOpsin

HRhodopsin11-cis-retinal

(aldehyde not imine)

Me Me

Me

Me

NOpsin

H

Me

all trans-retinalstarts VISUAL CASCADE

photon

11

12

$chemistry and medicine

penicillin Gantibacterial

HN

O N

S

O

H

CO2H

MeMe

http://staff.science.uva.nl/~dcslob/lesbrieven/maarten/Bacterien.html

N OHN

O

F

OH OH O

MeMe

Ca2+

2

Liptorcholesterol treatmentUS$ 12.9 billion

the language of chemistry...

the language of chemistry...

First we need to be able to communicate

with each other...

the language of chemistry...

There are three ways of talking about

chemicals...

SYMBOLICchemical formulae

MICROSCOPICatoms &

molecules

MACROSCOPICbulk

properties

©DC Comics

macroscopicrepresentation

physical properities

©DC Comics

macroscopicrepresentation

physical properitiesobviously important

(if you happen to get dunked in a vat

of the stuff)

©DC Comics

macroscopicrepresentation

physical properities

but ignored in this lecture...lets just

leave it for the lab...

how do we represent molecules?

microscopic representation

microscopic representation

how we represent the actual molecules

themselves...

molecular orbital representation

hexane

molecular orbital representation

hexane

electrons spread over entire molecule...true but not very useful!

hexane

space filling representation

hexane

space filling representation

shows us the atoms and their relative

size...but bonds hard to see

hexane

ball and stick representation

hexane

ball and stick representation

atoms, bonds, shape, it has it all. Time

consuming to draw so...

symbolic representation

symbolic representation

quick and dirty ways to represent molecules

C3H7

empirical formula

C3H7

empirical formula

just the ratio of atoms...

C3H7

empirical formulaempirical formula

C3H7

C6H14

C9H21

C12H28C15H35C18H42 C21H49

C24H56C27H63 C30H70

C33H77

...too many possibilities!

molecular formula

C6H14

molecular formula

C6H14exact number of atoms...

molecular formula

C6H14

molecular formula

HC

CC

CC

CH

H H

H H

H H

H H

H H

H H

HC

CC

CC

H

H H

C H

H H

H H

H H

HHH

HC

CC

CC

H

H H

H H H H

H HCH H

H

HH

CC

CC

HH H

C H

H C

H HH

HH

HH H

...but not how they are connected

condensedformula

CH3CH2CH2CH2CH2CH3

condensedformula

CH3CH2CH2CH2CH2CH3bonding sorted...

condensedformula

CH3CH2CH2CH2CH2CH3

condensedformula

HC

CC

CH

H H

C H

H C

H HH

HH

HH H

(CH3)2CHCH(CH3)CH3N

N

Me

MeO

O

N

NMe

...but bulky...and some structures

would be confusing!

structural formula

HC

CC

CC

CH

H H

H H

H H

H H

H H

H H

structural formula

HC

CC

CC

CH

H H

H H

H H

H H

H H

H H

now we’re talking; atoms, bonding,

shape. It has it all. But...

structural formula

HC

CC

CC

CH

H H

H H

H H

H H

H H

H H

structural formula

N

OMe

N

OH

HCN

CCC

HC

HCCH

CCH

O

CH C

HN CH2

CH2H2C CH

H2CCH

HC

H2COH

CH3

...can be messy and time consuming...

skeletal (structural) formula

skeletal (structural) formula

Quick, easy and tells me

everything...but do you understand what it means?

other representations

CC

C

CC

H

O

HH

H HH

H

HH

HH

OCHO

CHOH

CH3

OHEt

Ph

H

CH3

OH

H

HO

CH3HPh

Et H

Fischer projection

Newman projection

Sawhorse projection

do not use this representation!

H C C C C C C HH

H

H

H

H

H

H

HH

HH

H

do not use this representation!

H C C C C C C HH

H

H

H

H

H

H

HH

HH

H

©Lucasfilms

...key to this course is understanding / interpreting these

symbols

understanding skeletal (structural) formulae

4CARBON

HC

HHH

C CH

H H

H

CCO

H

H H

OH

H C C H

4CARBON

HC

HHH

C CH

H H

H

CCO

H

H H

OH

H C C H

carbon always has four bonds...

1HYDROGEN

HC

HHH

C CH

H H

H

CCO

H

H H

OH

CCC

H NO

OH

HH

H

H H

1HYDROGEN

HC

HHH

C CH

H H

H

CCO

H

H H

OH

CCC

H NO

OH

HH

H

H Hhydrogen always has

one bond...

2OXYGEN

HC

CO

H H

H HH

CCCOC

HH

HH

HH

HH

CCC

H NO

OH

HH

H

H H

3NITROGEN C

CC

H NO

OH

HH

H

H H

CC

NC

H

H HH

HH

C CH

HH N

2ELECTRONS

C H

O H

N H

2ELECTRONS

C H

O H

N H

we’ll explain why in a later lecture...

so how do we draw skeletal formulae?

allC CHcan be removedand

NH

HN

HN

NH

HN

NH

HN

OO

O

O

O

HO OHOH

O O

O

NH2

OHHO

O

Cl

Cl

O

HOHO

OH

OO

NH2OH

O

Vancomycin

O

HO

allC CHcan be removedand

NH

HN

HN

NH

HN

NH

HN

OO

O

O

O

HO OHOH

O O

O

NH2

OHHO

O

Cl

Cl

O

HOHO

OH

OO

NH2OH

O

Vancomycin

O

HO

assume each corner is a carbon...

allC CHcan be removedand

NH

HN

HN

NH

HN

NH

HN

OO

O

O

O

HO OHOH

O O

O

NH2

OHHO

O

Cl

Cl

O

HOHO

OH

OO

NH2OH

O

Vancomycin

O

HO...and it will always have four bonds.

example one

HC

CC

CHH H

H H

example one

HC

CC

CHH H

H H

CC

CC

– H

remove H

example one

HC

CC

CHH H

H H

CC

CC

– H – Cnow remove C

example two

CC

CCC

CHH

H

HH

H

example two

CC

CCC

CHH

H

HH

H

CC

CCC

C

– H

remove H

example two

CC

CCC

CHH

H

HH

H

CC

CCC

C

– H – Cnow remove C

example three

CC

O

OH

H

HH

H NH

H

example three

only removeCH

CC

CO

O

N

H

HH

CC

O

OH

H

HH

H NH

H

remove C–HBUT

leave all others!

example three

– Conly

removeCH

CO2H

NH2

OH

O

NH2CC

CO

O

N

H

HH

CC

O

OH

H

HH

H NH

H

now remove C

examplefourreverse

HOCO2H

NH2

examplefourreverse

HOCO2H

NH2

HOC

CCO2H

NH2

C+

add C to corners

examplefourreverse

HOCO2H

NH2

HOC

CCO2H

NH2HO

CC

CO2HH H

H NH2C+ H+ Add H to make all C have four bonds

examplefourreverse

HOCO2H

NH2

HOC

CCO2H

NH2HO

CC

CO2HH H

H NH2C+ H+

HOC

CC

H H

H NH2O

OH

HOC

CC

H H

H NH2O

OH

HOC

CC

H H

H NH2O

OH

remember C has four; O has two

bonds and H has one

CO2H

CHO

NC

examplefivereverse

CO2H

CHO

NCC

CC

CO2H

CC

CC

C

CHO

NC

HH

H H H

HH

examplefivereverse

add C to corners and H to make four

bonds

CO2H

CHO

NCC

CC

CO2H

CC

CC

C

CHO

NC

HH

H H H

HH

CC

CC

CC

CC

C

C

C

HH

H H H

HH

O

H

NO

OHexample

fivereverse

now get three bonds to N; two bonds to O and one to H

what have....we learnt?

4organic chemistry is easy if we can count to...

what have....we learnt?

4organic chemistry is easy if we can count to...

oh, and it’s really important!

(Dr. GJ Rowlands)

Acknowledgmentsgareth

wouldlike tothankTrevor Kitson

Massey University& the 101 students

www.massey.ac.nz/~gjrowlan

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