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Catabolism: What Is Catabolism?

What Is Catabolism? Learn What Catabolism Is And The Role It Plays In The Body.

Definition of Catabolism

Catabolism is a series of chemical reactions (via metabolic pathways in the body) that break down complex molecules into smaller units and release energy. This released energy is then stored within the molecule adenosine triphosphate (ATP).

Cells use ATP to:

  •  Synthesize cell components
  •  Power muscle contraction and motion
  •  Transport substances across cell membranes.

Catabolism is the opposite of anabolism, which is the process of creating larger, more complex molecules via metabolic pathways.

Examples and Types of Catabolism

The types of large molecules typically broken down by catabolism include:

  • Polysaccharides (starches and glycogen)
  • Lipids (fats)
  • Nucleic acids
  • Proteins

These large molecules are then broke down into smaller units such as:

  • Monosaccharides (simple sugars like glucose, fructose and galactose)
  • Fatty acids
  • Nucleotides (which are sources of chemical energy to ATP and guanosine triphosphate)  as well as cofactors to enzymatic reactions)
  • Amino acids

How Catabolism and Anabolism Relate to Metabolism

Catabolism and anabolism are the two fundamental metabolic processes in the body that maintain life.  Catabolism breaks down organic material to ”produce” energy, and anabolism uses that energy to build critical cellular components like nucleic acids and proteins.

So while catabolism is often viewed as a “bad thing”, it’s actually a pre-requisite for producing the chemical energy the body requires to create new cellular material and tissue, as well as support the repair, growth and maintainance of existing tissue.

When the rate of catabolism outpaces the rate of anabolism (for example, when a person is in an calorie deficit sate), net tissue is lost. When anabolism is greater than catabolism (i.e. a state of energy surplus), net tissue gain results. When catabolism and anabolism are in a relative state of balance, equilibrium results and net tissue levels are maintained constant.

What Controls Catabolism?

Catabolism is controlled via signals sent from hormones in the body. These hormones typically include cortisol (which the body produces when under physical or mental stress), glucagon and adrenaline, as well as cytokines, orexin, hypocretin