Transcript
Molecular BiologyThe Basics
AtomsSmallest unit of an
element still exhibiting qualities
of that element
Subatomic ParticlesAn atom has three parts
Negatively charged Electrons (e-)
Positively charged Protons (p+)
Neutrally charged Neutrons (n0)
• Protons and Neutrons are located in the
nucleus• Electrons travel around
nucleus in orbital shells
Atomic Structure• Electrons fill shells in
ascending order with a maximum number of electrons in each shell• The 1st shell has a
maximum of 2 electrons, the 2nd has a maximum of 8, the 3rd has a maximum of 18
• The outermost shell of an atom is called the valence shell and contains valence electrons
MoleculesMolecules are two or
more bonded atoms• Covalent bonds
have shared electronso Non-polaro Polar
• Hydrogen bonds• Ionic bonds• Metallic bonds
Non-polar Covalent Bonds
• Molecules share electrons equally and evenly
Polar Covalent
BondsElectrons shared slightly unevenly between atoms• Electrons spend more
time traveling around one atom creating a negative charge on one side and a positive charge on the other
Hydrogen BondsWhen polar molecules contain hydrogen atoms,
the opposite charges attract
nearby molecules
An atom with few valence electron will give
one to an atom with
many valence
electrons
A charged atom, or
ion, is created from the
p+/e-
imbalance
The opposite charges attract
and form a strong bond
Ionic Bonds
Metal atoms in formalized
structure share electrons
throughout entire molecule
• Leads to high conductivity of electricity
Metallic Bonds
Periodic Table
Elements are arranged by
a variety of properties
top related