Living cells are composed of a limited number of elements.
The chemical properties of an atoms are determined by ther number and arragments of their
electrons
The chemical bonds between atoms in form because electrons move to reach
a stable configuration.
An electron jumping atom to atom forms a positively charged ion
and one negative ion.
Mutual attraction between charged
atoms form ionic bonds.
Covalent bond: two atoms adjacent
When the atoms share two electron pais, its a double bond
Sugars, fatty acids, aminoacids and nucleotids form the principal
category of restricted and characteristic group of small molecules
with carbon ( eseential for life).
The primary source of energy for cells is sugar.
Sugar joins with
polysaccharides, whose
porpouse is store energy.
The fatty acids are important because
they reserve energy, also are the major
component in the cell membrane.
Most of the dry mass of the cell is composed by sugar
polymers , aminoacids or nucleotids
Macromolecules have an intermediate size
and complexity between small molecules and
cell organelles .
Polymers formed by amino acids are proteins that represent a diverse and versatile class of
macromolecules .
nucleotides play a central role in energy transfer.
Subunits that form part of RNA and DNA .
The molecules of the proteins of RNA and DNA are
synthesized since the subunits by repeating
condensation reactions.