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Ch. 2 - Basic Chemistry

Introduction to Basic Chemistry in Living Organisms

  • Living organisms are primarily composed of chemical elements.

  • Approximately 25 different chemical elements are considered essential constituents of living matter. i

  • Chemicals serve as the fundamental, base level within the biological hierarchy.

  • These basic chemical components are systematically arranged into progressively higher and more complex levels of structural organization, forming the foundation of biological systems.

The Biological Hierarchy

  • The biological hierarchy illustrates the ascending levels of organization found in living organisms, starting from the smallest chemical units and building towards a complete organism.

  • This structural organization progresses through the following levels:

    • Atom: The most basic unit of matter that retains the chemical properties of an element. It is composed of subatomic particles like protons, neutrons, and electrons.

    • Molecule: Formed when two or more atoms join together via chemical bonds.

    • Organelle: Specialized structures within a cell that perform specific functions, such as mitochondria or the nucleus.

    • Cell: The fundamental and smallest unit of life capable of carrying out all life processes. Cells are the basic building blocks of all organisms.

    • Tissues: Groups of similar cells that collaborate to perform a specific function (e.g., muscle tissue, nervous tissue).

    • Organs: Structures composed of two or more different types of tissues that work together to execute complex functions (e.g., the heart, lungs, stomach).

    • Organ Systems: Collections of organs that cooperate to perform major functions necessary for the survival of the organism (e.g., the digestive system, circulatory system).

    • Organism: A complete living being, representing the highest level of individual biological organization.

Fundamental Atomic Components

  • Atoms, the foundational units of matter, are comprised of various subatomic particles:

    • Proton: A subatomic particle located in the atomic nucleus, carrying a positive electrical charge.

    • Neutron: A subatomic particle also found in the atomic nucleus, characterized by having no electrical charge (it is neutral).

    • Electron: A subatomic particle that orbits the atomic nucleus, carrying a negative electrical charge.