Chemistry of the Cell
Why chemistry?
• Cells are made of chemicals
• Subcelluar structures, DNA, and membrane are made of
complex molecules
• Complex molecules are made up of simple molecules which
are composed of atoms
- >
CELLS SUBCELLULAR STRUCTURES COMPLEX MOLECULES
ATOMS -
SIMPLE MOLECULES
S
Atoms:
• Building block of molecules
• Subatomic Particles
- Protons (+Charge) in the center
&
- Neutrons (no charge)
- Electrons (-charge)
- Rotates around the center in their orbitals
• Atoms do not carry charges
Elements:
• Element: A substance made up entirely of one type of
atom
• Each element contains characteristic number of protons
and electrons.
- In stable elements, protons and electrons are equal
- This number is the same as the position on the table
• There are 118 elements
• Elements fall into groups with similar properties among
them
• Cells are made from a few types of elements
- Living organisms are made up of a few elements out
of the 89 natural occuring elements
- 96% of an organism's weight is mainly 4 elements:
carbon, hydrogen, oxygen, and nitrogen
, Molecules:
• When two or more atoms combine, they form a molecule
• The chemical bonds of molecules are formed when atoms
share, donate (lose), or accept (gain) electrons
The outermost electrons determine how atoms interact:
• An atom is most stable when all electrons are tightly bound
states that are possible (when they occupy the innermost
shells)
• An atom whose outermost shell is filled with the max
number of electron is stable and therefore chemically
-
unreactive
• Valence electrons: electrons in the outermost shell that
can be involved in chemical bonding
• The Octet Rule: Main group elements form bonds a manner
that results in each atom having 8 valence electrons in its
outermost shell (there are exception, such as for Hydrogen)
Why chemistry?
• Cells are made of chemicals
• Subcelluar structures, DNA, and membrane are made of
complex molecules
• Complex molecules are made up of simple molecules which
are composed of atoms
- >
CELLS SUBCELLULAR STRUCTURES COMPLEX MOLECULES
ATOMS -
SIMPLE MOLECULES
S
Atoms:
• Building block of molecules
• Subatomic Particles
- Protons (+Charge) in the center
&
- Neutrons (no charge)
- Electrons (-charge)
- Rotates around the center in their orbitals
• Atoms do not carry charges
Elements:
• Element: A substance made up entirely of one type of
atom
• Each element contains characteristic number of protons
and electrons.
- In stable elements, protons and electrons are equal
- This number is the same as the position on the table
• There are 118 elements
• Elements fall into groups with similar properties among
them
• Cells are made from a few types of elements
- Living organisms are made up of a few elements out
of the 89 natural occuring elements
- 96% of an organism's weight is mainly 4 elements:
carbon, hydrogen, oxygen, and nitrogen
, Molecules:
• When two or more atoms combine, they form a molecule
• The chemical bonds of molecules are formed when atoms
share, donate (lose), or accept (gain) electrons
The outermost electrons determine how atoms interact:
• An atom is most stable when all electrons are tightly bound
states that are possible (when they occupy the innermost
shells)
• An atom whose outermost shell is filled with the max
number of electron is stable and therefore chemically
-
unreactive
• Valence electrons: electrons in the outermost shell that
can be involved in chemical bonding
• The Octet Rule: Main group elements form bonds a manner
that results in each atom having 8 valence electrons in its
outermost shell (there are exception, such as for Hydrogen)
