Bio Notes

REVIEW UNIT 1-THE CELL LIFE *There is no def. for life *Life can be characterized by a list of things that we might agree living thing have in common-organized and contain complex chemical substances, Made up of one or more cells, Use Energy, Have a definite form& Limited size, Have a limited life Span, Grow, Respond to changes in the environment, Reproduce, Evolve over time.*Metabolism is all the chemical reaction occurring

in the cell of an organism*All Living things must carry out processes to maitain life and homeostasis- Nutrition, Transport, Respiration, Synthesis and Assimilation, Growth, Excretion, Regulation, Reproduction, Metabolism.CHEMISTRY BASICS *Atoms of the elements are the basic unit of mattter and are composed of protons, neutrons and electrons.*Atomic mass is the sum of the number of protons and nuetrons in an atom.*The number of protons and electrons is the same as the atomic number.*Isotopes of an element differ in the number of nuetrons,*The outer most electrons of an atom are called valence electrons and are evolved in chemical bonding.*Covalent bonds between elements involve the sharing of a pair of electrons. *Transferring an electron betwwen atoms and then the pos. and neg. charged atoms bonding together by charge forms ionic bonds. *2 adjacent molecules sharing ahydrogen atom forms hydrogen bonds*A chemical formula indicates the type and number of elements in a molecule.* A structural formula indicates the type, number, and bonding between elements in a molecule.*Chemical reaction are composed of reactants and products and the number of atom of elements of the reactants must equal the # of elements in the products, i.e. Chemical equations must be balanced in the number of elements.* Mixure are composed of different substances that are not chemically bonded,*Mixures where substances are mixed but exist as individual molecules are called solutions. TRhe subst. making up the bulk of the mixure is called the solevent and the other material(s) is called the solute(s).* A liquid mixure where the material tends to stay is called suspension. ver time the suspended materials do settle.*A colloidal dispertion is liquid mixure where the suspended material particals are bigger than molecules,but do not ever settle.*pH is a measure of hydrog ion concent. the larger the pH number the lower the hydro bond concentration. Each whole pH indicates a 10 change in pH.*Bases have a pH betwwen 7 and 14 and acids have a pH below 7.BIOLOGICAL CHEMISTRY*All organic compounds contain carbon. Only a few compounds containing carbon are not organic such as carbon dioxide.*Carbon's 4 valence electron and ability to for 4 covalent bonds allows it to be the basic chemical element for life.* water is an essential

component ot life due to the chemical props of water: *Polar molecule due to strong electron attraction of oxygen. *Polar nature of water makes it a good solvent and ion conductors.*Has a high capac. to hold heat.*Water has high adhesion and is cohesive to many other substances which acause capillary action.*Molecules have groups of atoms that have a particular chemical func. and are called func. groups. Important func. gruops in organic molecules includ: Hydroxyl or alcohol(-OH), carboxyl or acid(-COOH), amine or base(-NH2)*Carbohydrates are complex compounds composed are carbon, hydrog and oxy having both a food(energy) and stuctural role in life as well as a component of other molecules.*simplist form carbohydrate are recognized

because they contain twice as many hydrogens and oxygens.*Carbohydrated form polymers by dehydration systhesis of monosaccharides. Starch is a Polymer of glucose.*Carbohydrate polymers can be broken down into monosaccharidesby hydrolysis. Specific enzymes