& Healing Centre
|
|
|
Metabolism Support.
A striking feature of metabolism is the similarity of the basic
metabolic pathways between even vastly different species. For example, the set
of carboxylic acids that are best known as the intermediates in the citric acid
cycle are present in all organisms, being found in species as diverse as the
unicellular bacteria Escherichia coli and huge multicellular organisms like
elephants. These striking similarities in metabolism are most likely the
result of the high efficiency of these pathways, and of their early appearance
in evolutionary history.
Metabolism is the set of chemical reactions that occur in living organisms to
maintain life. These processes allow organisms to grow and reproduce, maintain
their structures, and respond to their environments. Metabolism is usually
divided into two categories. Catabolism breaks down organic matter, for example
to harvest energy in cellular respiration. Anabolism, on the other hand, uses
energy to construct components of cells such as proteins and nucleic acids.
The chemical reactions of metabolism are organized into metabolic pathways, in
which one chemical is transformed into another by a sequence of enzymes. Enzymes
are crucial to metabolism because they allow organisms to drive desirable but
thermodynamically unfavorable reactions by coupling them to favorable ones, and
because they act as catalysts to allow these reactions to proceed quickly and
efficiently. Enzymes also allow the regulation of metabolic pathways in response
to changes in the cell's environment or signals from other cells.
The metabolism of an organism determines which substances it will find
nutritious and which it will find poisonous. For example, some prokaryotes use
hydrogen sulfide as a nutrient, yet this gas is poisonous to animals. The
speed of metabolism, the metabolic rate, also influences how much food an
organism will require.
A striking feature of metabolism is the similarity of the basic metabolic
pathways between even vastly different species. For example, the set of
carboxylic acids that are best known as the intermediates in the citric acid
cycle are present in all organisms, being found in species as diverse as the
unicellular bacteria Escherichia coli and huge multicellular organisms like
elephants. These striking similarities in metabolism are most likely the
result of the high efficiency of these pathways, and of their early appearance
in evolutionary history.
