Molecular biology

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