From Wikipedia,
the free encyclopedia.
A few of the metabolic
pathways in a cell.
Cell metabolism is the
process (or really the sum of many
ongoing individual processes) by
which living
cells process nutrient
molecules and maintain a living
state. Metabolism has two distinct
divisions: anabolism, in
which a cell uses energy and
reducing power to construct
complex molecules and perform
other life functions such a
creating cellular structure; and
catabolism, in which a cell
breaks down complex molecules to
yield energy and reducing power.
Cell metabolism involves extremely
complex sequences of controlled
chemical reactions called
metabolic pathways.
Anabolism
Main article:
Anabolism
Anabolism is a
constructive
metabolic process whereby
energy is consumed to synthesize
or combine simpler substances,
such as
amino acids, into more complex
organic compounds, such as
enzymes and
nucleic acids.
Catabolism
Catabolism is a type of
metabolic process occurring in
living
cells by which complex
molecules are broken down to
produce energy and reducing power.
On balance, catabolic reactions
are normally
exothermic.
Carbohydrate catabolism
Main article:
Carbohydrate catabolism
Carbohydrate catabolism is the
breakdown of carbohydrates into
smaller units. The empirical
formula for carbohydrates, like
that of their monomer
counterparts, is CX(H2YOY).
Carbohydrates literally undergo
combustion to retrieve the large
amounts of energy in their bonds.
Read more about
mitochondria to find out more
about the reaction and how its
energy is secured in
ATP.
Fat catabolism
Main article:
Fat catabolism
Fat catabolism, also known as
lipid catabolism, is the process
of lipids or phospholipids being
broken down by
lipases. The opposite of fat
catabolism is
fat anabolism, involving the
storage of energy, and the
building of membranes.
Protein catabolism
Main article:
Protein catabolism
Protein catabolism is the
breakdown of proteins into
amino acids and simple
derivative compounds, for
transport into the cell through
the
plasma membrane and ultimately
for the polymerisation into new
proteins via the use of
ribonucleic acids (RNA)
and
ribosomes.