LECTURE 1 AND 2 :
THE CHEMISTRY OF LIFE
o
ELEMENTS IMPORTANT FOR LIFE
o
elements bond in specific ratios →
compounds .
elements
"
it
"
not
yield emergent properties would expect purely analysing
- =
o
living matter =
25 essential elements
But
carbon
hydrogen
nitrogen 96T of living matter .
oxygen
phosphorus
sulfur -
eg
. human body =
651 Oxygen .
=
18,51 carbon .
9,5% hydrogen
=
=
3,21 nitrogen
.
.
o
true elements =
less than 0,01%
* deficiencies in essential elements leads to problems !
low iron anemia
eg
=
.
↳ iron
hemoglobin production
vital in low iron low 02 transport
=
= . :
o
in plants yellowing of leaves symptom of :
dizzy feeling
=
,
iron
deficiency .
low goiter
iodine
=
eg •
enlargement of thyroid gland
control metabolism development
thyroid hormones t
0 .
o
ELEMENTS :
ATOMIC STRUCTURE
o atom →
smallest unit of matter that still retains the properties of the element
•
atomic number =
no .
of pt ( and no .
of e- in neutral atom)
mass number no
if pt of no
=
o
. + no .
e- no
1800 ✗ smaller than pt or
=
→
one a
, 0
ISOTOPES
0
atoms with the same number of protons and electrons but different no .
neutrons
of
.
normal , stable
protium hydrogen
=
o
deuterium heavy hydrogen 1 stable)
or =
o tritium =
radioactive 1 unstable )
0
radioactive isotopes →
nucleus
decays spontaneously giving off particles ,
t
energy .
- uses : tracers in medicine to
identity cancer / disease leg PET scans )
:
destruction of cancer cells
leg . Cobalt -
607
DNA / abnormal bonds
B¥ dangerous as they can
damage , break bonds cause
to
form .
0
ELECTRON SHELLS AND ORBITALS
o
orbitals =
contained within electron shells
( 3D space where an electron spends 90% of its time
Energy 9 as move up electron smells
.
you
o o
↳ must absorb / release energy to move between
electron shells
_
Carson -12
:
'" "
eg diagram
?
.
:
2p 1¥
.
e-
e- is
e-