Term | Definition |
Adenosine triphosphate (ATP) | stores the energy released from the breakdown of nutrients and provides it to fuel cellular reactions |
acid | any substance that releases hydrogen ions in solution; pH less than 7 |
amino acid | organic compounds containing an amino group and a carboxyl group that are the building blocks of proteins |
anabolism | the constructive phase of metabolism during which cells use nutrients and energy for growth and repair |
anion | an ion with a negative electrical charge |
atom | the smallest part of an element; consist of a nucleus containing protons and neutrons surrounded by electrons |
atomic number | the number of protons in the nucleus of an element |
atomic weight | the number of protons and neutrons added together |
base | any substance that combines with hydrogen ions' pH greater than 7 |
carbohydrates | group of organic compounds known as starches or sugars that serves as the body's primary source of energy |
catabolism | phase of metabolism during which complex substances are converted to simpler ones, resulting in the release of chemical energy |
cations | an ion with a positive electrical charge |
compound | chemical combination of two or more elements |
covalent bonds | bond formed between two atoms when the atoms share one or more pairs of electrons |
electrolytes | a compound that dissociates in water to create a solution capable of conducting electricity |
electron | minute particle with a negative charge that revolves around the nucleus of an atom |
element | a substance that cannot be separated into substances different from itself |
enzymes | substances that change the rate of chemical reactions without being changed themselves |
glucose | monosaccharide that serves as the primary source of energy for most of the body's cells |
hydrogen bond | a weak attraction between a slightly positive hydrogen atom in one molecule and a slightly negative oxygen or nitrogen atom in another |
ion | electrically charged atom |
ionic bond | bond formed when one atom transfers an electron from its outer shell to another atom |
isotope | one of a series of chemical elements that have nearly identical chemical properties but different atomic weights and electrical charges; many are radioactive |
lipid | group of fats characterized by their insolubility in water |
matter | anything that has mass and takes up space |
metabolism | the sum of all the chemical reactions in the body |
molecule | a combination of two or more atoms held together by chemical bonds |
neutron | particle without an electrical charge contained in the nucleus of an atom |
pH | a measure of the hydrogen ion concentration of a solution |
proteins | very large molecules consisting of smaller chemical subunits called amino acids |
triglyceride | most abundant lipid that functions as a source of energy in the body |
energy | the capacity to do work; to put matter into motion |
potential energy | energy that is stored in the bonds of molecules |
kinetic energy | energy in motion |
solution | particles of matter dissolved in a more abundant substance; can be a gas, solid, or liquid; particles cannot separate out when allowed to stand. |
colloid | in the human body thes are mixtures of protein in water; can change from liquid to gel; particles are small enough to stay perminently mixed but large enough so that the mixture is cloudy |
suspension | contians large particles; if allowed to stand the particles will separate out and settle at the bottom of the container |
glycogen | the stored form of glucose |
monosaccharide | contains one sugar unit |
disaccharide | contains two sugar units |
polysaccharides | contain many sugar units joined together |
starch | the form in which plants store polysaccharides; examples are rice, potatoes, and corn; when consumed the digestive enzymes split the starch molecule and release glucose |
cellulose | humans cannot digest this form of polysaccharide, it supplies fiber in the diet |