Metabolism?is a catch-all term used to describe?all the chemical reactions?that take place within cells and organisms
Metabolism can be thought of as?the chemical reactions of life
The molecules involved are?metabolites
Many reactions of metabolism take place in?multiple stages
Each stage is?catalysed?by a separate?enzyme
A series of interlinked metabolic reactions is called a?metabolic pathway
Metabolic reactions can be classified broadly as?anabolic?or?catabolic
Anabolism
Anabolic reactions are involved with the building of large molecules from smaller ones
Examples include;
Photosynthesis, where CO2?and water are built up into complex sugars
Protein synthesis, where amino acids are joined together in sequence
The buildup of fat stores ahead of animal hibernation
Anabolic reactions often include?condensation?reactions
Anabolic reactions are?endergonic?(they require an input of energy to take place)
Energy-storing products are the end result
Catabolism
Catabolic reactions are involved with?breaking down large molecules?into smaller ones
These reactions are often carried out to?release energy?for cellular processes and for the?excretion?of waste
Examples include:
Respiration, where CO2?and water are produced from the breakdown of sugars
Deamination?of proteins to release urea
The?depletion of fat stores?during animal hibernation
Catabolic reactions often include?hydrolysis?reactions
Catabolic reactions are?exergonic?(free energy is released for cellular processes or as excess heat)
Comparison of Anabolism and Catabolism Table
Exam Tip
You may be familiar with the concept of anabolic steroid drugs used by bodybuilders. This is to build muscle mass and so is a good example to remember when trying to remember the difference between anabolic and catabolic reactions.