Metabolism

Metabolism is the set of life-sustaining chemical reactions in organisms. The three main purposes of metabolism are the conversion of food to energy to run cellular processes; the conversion of food/fuel to building blocks for proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of nitrogenous wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments.

Key Points to Remember:

• Metabolism is the sum of all chemical reactions that occur within an organism.
• Metabolism can be divided into two categories: catabolism (breaking down molecules to release energy) and anabolism (building molecules that require energy).
• Metabolic pathways are series of chemical reactions that take place in a specific order to achieve a particular goal.
• Enzymes are proteins that act as catalysts in metabolic reactions, speeding up the reactions without being consumed.

Study Guide Questions:

1. What is metabolism? Explain the two main categories of metabolism.
2. Describe the role of metabolic pathways in the functioning of an organism.
3. How do enzymes contribute to metabolic reactions? Provide examples of specific metabolic reactions.
4. What are the main purposes of metabolism in living organisms?