Essential Chemistry For Biology Chapter 2 PDF

DMR P NK notes DNR Essential Chemistry For Biology Chp 2 all biological system can be viewed as...

DMR P NK notes DNR Essential Chemistry For Biology Chp 2 all biological system can be viewed as a vast collection of chemicals reactions digesting food moving muscles thinking matter is anything that occupies space and has matter mass is a measure of the amount material in o ob eat composed of chemical chemical element be element is substance that cannot a broken down into pure substanie DMR P NK notes DNR 92 natural occuring elements symbols derived from it Eng Lat or Germ name human made element 92 natural element are listed on 92 elements 25 are essential to humans I 4 element O C H N makeup 96 of human body weight other 4 is simular to Ca Calcium Ca is important for building bones teeth Less than 0.02 of your weight is trace elements essential elements for survial in small quantities DMR P NK notes DNR Compounds are substances that contian two or more different elements fixed ratio Example NaCl sodium chloride table salt emergent property arised from bio systems Atom atom the smallest unit of matter that still retains the properties of an element proton positive electron negative charged charged neutron electrically neutral Subatomic particals DMR P NK notes DNR atomic number is the unique number of protons mass number is the sum of number of protons neutrons in it nucleus Isotopes same numbers of protons but different neutrons but behave identically in chemical reaction due to same electron Radioactive isotope nucleus decays spontaneously DMR P NK notes DNR only electrons directly involved in chemical reaction number of electrons determines the chemical properties Chemical bounds Molecules only electron are directly involed in chemical reactions number of electrons determine chemical props of atoms Chemical reaction enable atoms to transfer or share electrons cause chemical bonds atoms stay close together DMR P NK notes DNR Ionic Bonds ions atoms or molecules that are electrically charged as a result of gaining or losing electrons fall charge polar as compound atoms with the same number of protons but with different electrical charges are different ion ionic bonds the attraction bw oppositely charged ions gives away electron Example Nat C1 11 protons Sodium Chloride 17 10 electron proton 18 election hold atoms together to make molecines DMR P NK notes DNR Covalent Bonds when 2 or more atoms share one or more pairs of electrons strongest bound molecule group of two or more atom held together by a covalent bond bond single c I H H water is able to separate bounds hold atoms together to make molecines polar or nonpolar as compounds DMR P NK notes DNR Hydrogen bonds weak chemical bond when Hydrogen bond is attracted the midly negative atom in other molecule polar H2O water has 2 hydroden atoms joined by one oxgen atom by a single covalent bonds electrons are not shared equally bw oxygen hydrogen atoms stronger pull on shared electron oxygen creates V shape makes it polar polar molecule molecule that has an is a uneven distribution of charge due to presence of polar covalent bonds Higher slight slightly Fluriene pos surface cos Nitrogen tension Oxygen slightly hydrogen neg DMR P NK notes DNR Chemical Reactions Chemical reactions the transformation of matter making or breaking of chemical bounds rearranging of atoms 2H20 2H20 02 Hydrogen water Oxygen Peroxide UV products Reactants end materials starting materials si DMR P NK notes DNR Water Life all life is tied to water cells composed of based fluid are a mainly water 70 to 95 of cells is water content water is vital to sustain life on other planets Water's properties by hydrogen bonds cohesion attraction bw molecules of same kind example trees transport of water from roots to leaves High surface tension High specific hydrogen bond are harder to break evaporating cooling a body of water becomes cool as water evaporates from it sweat DMR P NK notes DNR Less dense as a solid molecus spread out hydrogand bonds last longer floating ice acts as a insolator as life is still sustaind under frozer layer Solvent of life solution homogeneous mixture of two or more substances solvent dissolving agent water solute substance that is dissolved name based of solute aqueous solution when water is the solvent DMR P NK notes DNR Acids Bases ph acid a substance that increased the hydrogen ions H concentration in a solution base alkali substance that decreased the hydrogen ion figentration in a solution neutral substance that has equal H OH in a solution PH scale measure of relative acidity of a solution buffers substance that minimize change in PH decreased hydrogen ion Ht PH of most living thing are 7 Acid neutral basic 0 6 4 8 14