food - any substance that your body can use as a raw material to sustain its growth, repair it and provide energy enzymes - special proteins that catalyze (speed up) specific molecular reactions that would otherwise take place very slowly substrates - molecules that bind to specific places on enzymes

cellular respiration - aerobic production of molecules such as ATP that the body uses for energy aerobic - occurring in the presence of oxygen fermentation - creates less energy in the absence of oxygen

anaerobic - does not require oxygen toxins - substances that ultimately cause diminished performance or impairment of health amylase - enzyme found in human saliva starch - energy storage molecule in plants

digestive system - group of organs that breaks down food into small molecules amino acids - required for repairing and growing muscle tissue; creates proteins Kcals - food value mitochondria - cell organelles that create energy

macromolecule - large molecules made of chains of smaller molecules (repeating units called monomers) carbohydrate - sugars; monomer = monosaccharides lipid - fats; made of triglycerides (3 fatty acids and a glycerol) protein - made of amino acids linked together in chains called polypeptides

monomer - single subunit that makes up macromolecules monosaccharide - single sugar molecule; monomer of carbohydrates disaccharide - 2 monosaccharides linked together polysaccharide - 3 or more monosaccharides linked together

dehydration synthesis - chemical reaction in which two monomers join and release water hydrolysis - reaction where a macromolecule is broken into monomers by absorbing water denature - destroy the characteristics of a molecule (usually protein) by heat, acidity or other effects catalyst - substance that increases rate of a reaction (ex: enzymes)