Anatomy and Physiology: The Chemical Level of Organization

Introduction to Matter and AtomsPage 3

Matter is anything that occupies space and has mass. Elements are pure substances consisting of a single type of atom, which is the smallest unit retaining an element's properties. Atoms are composed of subatomic particles: protons (positive), neutrons (neutral), and electrons (negative).

Atomic Structure and IsotopesPage 10

An atom's identity is defined by its atomic number (number of protons). Isotopes are different forms of an element that vary in the number of neutrons and atomic weight. Electrons reside in shells, with the outermost 'valence' shell determining how an atom reacts and bonds with others.

Chemical BondsPage 19

Chemical bonds hold atoms together to achieve stability. Ionic bonds form via electrical attraction between oppositely charged ions. Covalent bonds, which can be polar or nonpolar, involve sharing electrons. Hydrogen bonds occur between molecules, such as between water molecules, providing surface tension.

Chemical Reactions and EnergyPage 29

Energy in the body exists as potential, kinetic, or chemical energy. Chemical reactions involve reactants transforming into products and are classified as synthesis, decomposition, or exchange. Enzymes act as catalysts to accelerate these reactions by lowering activation energy.

Inorganic CompoundsPage 41

Inorganic compounds, such as water, salts, acids, and bases, do not contain both carbon and hydrogen. Water is vital for life as a solvent, lubricant, and participant in hydrolysis and dehydration synthesis reactions. pH is a measure of acidity or alkalinity, maintained by buffers.

Organic Biological MacromoleculesPage 57

Organic molecules contain both carbon and hydrogen. The four major classes are: carbohydrates (primary energy source), lipids (insulation and energy), proteins (structure and catalysis), and nucleic acids (genetic information). Each consists of specific monomers that polymerize to fulfill vital roles in the body.