Chemical reactions

Definition

Chemical reactions involve the transformation of one or more substances into different substances through the breaking and forming of chemical bonds. These processes are fundamental to biological systems and underpin many physiological functions.

5 Must Know Facts For Your Next Test

1. Chemical reactions are governed by the principles of thermodynamics and kinetics.
2. Enzymes in biological systems act as catalysts to speed up chemical reactions without being consumed.
3. Reactants are the starting materials in a chemical reaction, while products are the substances formed.
4. Conservation of mass dictates that the mass of reactants equals the mass of products in a closed system.
5. Chemical reactions often involve changes in energy, typically seen as endothermic (absorbing heat) or exothermic (releasing heat).

Review Questions

• What role do enzymes play in chemical reactions within biological systems?
• How does the conservation of mass apply to chemical reactions?
• Explain how energy changes can categorize chemical reactions as endothermic or exothermic.

Related terms

Atom: The basic unit of a chemical element, consisting of protons, neutrons, and electrons.

Molecule: A group of atoms bonded together representing the smallest fundamental unit of a chemical compound.

Ion:

An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.