Metabolism is the sum of all chemical reactions that maintain an organism’s life and health. Metabolism includes two broad kinds of reactions. Anabolic reactions join smaller molecules or atoms to form larger molecules. Catabolic reactions break bonds in larger molecules, producing smaller molecules or atoms.
Both kinds involve energy. Chemical reactions need enough energy for particles to collide with sufficient force and precision to break old bonds and form new ones.
All flashcards
What is metabolism?
Metabolism is the sum total of the chemical reactions that maintain an organism’s health and life.
How do anabolic and catabolic reactions differ?
Anabolic reactions build larger molecules from smaller components. Catabolic reactions break larger molecules into smaller components.
What is chemical energy?
Chemical energy is potential energy stored in chemical bonds. Breaking bonds requires energy; forming bonds releases energy.
What distinguishes exergonic from endergonic reactions?
Exergonic reactions release more energy than they absorb. Endergonic reactions absorb more energy than they release.
Name three forms of energy besides chemical energy that matter in human functioning.
Mechanical energy powers movement, radiant energy travels as waves, and electrical energy supports voltage changes involved in nerve and muscle impulses.
Quiz questions
In a chemical equation, where are the reactants conventionally written?Answer: On the left side of the arrow.
Which description characterizes a synthesis reaction?Answer: Separate components join to form a larger substance.
What does a double arrow in a chemical equation indicate?Answer: The reaction can proceed in either direction under suitable conditions.
How does a catalyst affect a chemical reaction?Answer: It increases the reaction rate without undergoing a lasting change.
Which substances can function as enzymes in the body?Answer: Proteins or RNA molecules.
Based on Anatomy and Physiology 2e by J. Gordon Betts, Kelly A. Young, James A. Wise, Eddie Johnson, Brandon Poe, Dean H. Kruse, Oksana Korol, Jody E. Johnson, Mark Womble, Peter DeSaix (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.