Summary
The sum of all chemical reactions in an organism, including anabolic building and catabolic breakdown.
In depth
Metabolic pathways are sequences of enzyme-catalysed steps, each regulated. Catabolism releases energy, anabolism consumes it. Cells need to coordinate them so they are not run simultaneously in futile cycles.
Metabolic rate varies with size and activity.
Metabolism involves hundreds of reactions linked into networks. Regulation matches supply to demand. Enzymes are organised in compartments and complexes for efficiency.
Key idea: all metabolism is driven by energy flow and controlled by enzymes.
Metabolism is the whole network of enzyme-catalysed chemical reactions that keep a cell alive. It is organised into pathways, in which the product of one reaction is the substrate of the next, and it serves three goals: obtaining energy, building cell materials and removing wastes.
Reactions are controlled by enzymes, whose amounts and activities are regulated, and linked by shared currencies such as ATP, NADH and acetyl-CoA. Energy changes follow the laws of thermodynamics, so living things must continually take in energy to maintain order.
Example: a muscle cell shifts from burning fat at rest to glucose during a sprint.
Key idea: metabolism is the same basic chemistry shared by almost all life, evidence of common ancestry.
Frequently asked questions
What is Metabolism?
The sum of all chemical reactions in an organism, including anabolic building and catabolic breakdown.
Which area of biology covers Metabolism, and how advanced is it?
Metabolism is one of the 53 topics in Metabolism & Bioenergetics. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Metabolic Pathways Regulation, Thermodynamics of Metabolism, Anabolism and Catabolism.
Can you give an example of Metabolism?
Digestion of food is catabolic, building muscle protein is anabolic.
What should I learn before Metabolism?
Metabolism is a Beginner topic, so no earlier topic is required. Other Beginner topics in Metabolism & Bioenergetics that pair well with it include Anabolism and Catabolism, ATP, Cellular Respiration.
What topics are related to Metabolism?
The closest topics to Metabolism are Metabolic Pathways Regulation, Thermodynamics of Metabolism, Anabolism and Catabolism, ATP. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Metabolism?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Metabolism. To practise the whole of Metabolism & Bioenergetics, use the Metabolism & Bioenergetics quiz.
How is Metabolism different from Metabolic Pathways Regulation?
Metabolism: The sum of all chemical reactions in an organism, including anabolic building and catabolic breakdown. Metabolic Pathways Regulation: Key enzymes are controlled by feedback, allosteric effectors and hormones like insulin. Read both side by side and note what each one explains.
How should I study Metabolism step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Metabolic Pathways Regulation and explain the difference aloud. Finally, take the Metabolism & Bioenergetics quiz and come back to this page for any question you miss.