anything that occupies space and has mass3 states of matter: gas, liquid, solid.


a force that can effect matter2 forms: -kinetic energy= action energy-potential energy=stored energy


Simplest chemical units of matter

Subatomic Particles

Proton: positive electric charge, in nucleusNeutron: no electric charge, in nucleusElectron: negative electric charge, outside of nucleus


is an atom that will lose or gain an electron


a component of matter that cannot be simplified without changing its properties92 elements occur naturally.


Some elements may include atoms with a variable number of neutrons

Some elements may include unstable atoms, which lose subatomic particles. Energy released during this loss is called __________


What substance is composed of two or more atoms when they combine together in a chemical bond.


What molecule is composed of two or more different kinds of atoms


Chemical Bond

is a force holding two atoms together-ionic bond=bond formed when atoms gain or lose electrons-covalent bond= bond formed when atoms share one or more electrons

Ionic Bonds

-Requires one atom to lose an electron to become apositively charged ion, and another atom to gain an electron to become anegatively charged ion.-The ionic bond forms when the positive and negative ionsmeet and are held together by electrical forces of opposite charge.

Covalent Bonds

-Electrons from outer energy levels are shared between atoms.-Sharing of electrons forms an electrical force, establishing a stable bond.-May form single or double covalent bonds.-Common in large organic molecules.

A ______ _______ is the process of forming and breaking chemical bonds, in which reactants form products

Chemical reaction

A + B --> AB

Synthesis reaction

AB --> A + B

Decomposition reaction

AB + CD --> AD + BC

Exchange reaction

Chemical reactions in the body are essential for all functions to occur, especially in ________.



is a mixture of chemicals that includes asolvent and one or more solutes.-Solvent: the medium containing particles that are suspended in a dissolved, or ionized, state. It may be a gas, liquid, or solid. -Solute: the particles within a solvent that are suspended in a dissolved, or ionized, state.

Inorganic Compounds

Do not contain chains of carbon atoms, and are usuallyheld together by ionic bonds. They include water, salts, and most acids/bases

Water is essential for life because

-universal solvent-important transport medium-has a high heat capacity-an effective lubricant


an inorganic compound that dissolves in a liquidsolvent, forming ions.-Process of dissolving, or ionization, is a decomposition reaction.-Because certain salts play important roles in body functions, they are called electrolytes. -The most important electrolytes include Na+, Cl-, K+, and Ca2+


a molecule that releases one or more hydrogen ions


a molecule that reduces the concentration of hydrogen ions into a solution

Organic Compounds

Contain one or more carbon atoms that often form large molecular chains, stabilized by covalent bonds.-Form the basis for structure and function.4 main groups:-Carbohydrates-Lipids-Proteins-Nucleic acids


Sugar and Startches water solubleprovide primary source of energy for cells in the form of glucose-monosaccharides = simple sugars (glucose, fructose)-disaccharides = two simple sugars (maltose)-polysaccharides = more than two simple sugars (starch, glycogen)they combine by dehydration synthesis and break apart by hydrolysis


The fats, which do not dissolve in water, but in alcohol,ether, and other fatsprovide membrane structure and a secondary source of energy for the cell.1.Neutral fats or triglycerides (fats and oils): composed of fatty acids and glycerol-saturated fats (saturated with H atoms) -unsaturated fats (double covalent bonds)Important as an energy source, insulation, and protection.2.Phospholipids- which are composed of fatty acids and glycerolThey are a major component of cell membranes.3.Steroids- which are ring-shaped molecules, they contribute to membrane structure and form some hormones.


The most abundant organic compound in the cell Major contribution in cell structure and function (as enzymes).Composed of amino acids, of which there are 20 types capable of binding to form long chains. The covalent bond between amino acids is called a peptide bond, formed by dehydration synthesis.The result of a peptide bond is a dipeptide; a chain with more than 10 amino acids is a polypeptide, and more than 100 is a protein. Many proteins contain thousands of amino acids.The sequence of amino acids determines the role of the protein in the body, either as a structural component or as an enzyme.Amino acid sequence is coded by the genes in DNA

Primary roles of proteins include:

-Structural support-Transport-Movement-Metabolism-Regulation-Communication


perform the work of the body by serving as catalysts for chemical reactionsAn enzyme-mediated reaction changes a substrate to form a new product by chemically binding to an active site on the substrate molecule.

Nucleic Acids

-Extremely large, composed of many nucleotide subunits-Each nucleotide consists of a 5-carbon sugar, a phosphate group, and a nitrogen base (either adenine,guanine, cytosine, thymine, or uracil)-Nucleotides are linked by dehydration synthesis to form adouble spiral called DNA (deoxyribonucleic acid) or a single spiral called RNA(ribonucleic acid)-DNA is important because its sequence of nucleotides establishes the genetic code, which identifies protein structure during theprocess of protein synthesis-RNA is important because it participates in the process ofprotein synthesis.

High Energy Compounds

To perform body functions, energy must be stored in a temporary form so that it can be used when needed to power enzymes. This form is in the chemical bonds of a compound called ATP (adenosine triphosphate).ATP molecules store the energy as potential energy, primarily in the bond between ADP and a phosphate group:ATP <-- --> ADP + phosphate group + energyThe reaction is reversible, showing ATP can release energy to power an enzyme and it can be restored by adding energy. This reversible process is achieved by metabolism within cells.