Matter and EnergyElements in human bodyAtomsMolecules & CompoundsChemical BondsChemical ReactionsBiochemistryChemistry UnitMatter and Energy - Matter – anything that occupies space - Energy – the ability to do worko Kinetic – energy from movement (muscle contractions) o Potential – energy that is stored (can be used; potential to do work) o Chemical – energy that is stored in chemical bonds (energy in chemical bonds is potential energy)  When chemical bonds are being made energy is trapped in them; when they are broken energy is released to do worko Electrical – cells crossing with ions o ATP (chemical energy)  Ribosomes make Have 3 high energy chemical bonds  When body needs energy a bond in the ATP molecule is broken When bond is broken- Left with 2 phosphate bonds ATP build up and break down – going on all the time Elements in human body - 3 separate groups o Major – (carbon, oxygen, hydrogen and nitrogen) Primary components of large macromolecules such as DNA and protein o Lesser - (calcium and potassium) Still vital just make up a smaller amount in the body o Trace elements Atoms - Fundamental units of element- Atoms are neutral o Always have same number of protons and electrons to balance the charge out - Have a dense inner nucleuso Protons and Neutrons located inside the nucleus- Protonso Positive charge o Mass equal to 1 atomic mass unit - Neutronso Neutral chargeo Mass equal to 1 am- Electrons o Orbit the nucleus o Negative charge o Mass = extremely tiny (almost no mass) - Atomic # - represent number of protons o Defines the element but some elements have different structural forms - Mass # - protons + neutrons - Isotopes o All have the same atomic # but different mass # because they havesame number of protons but different number of neutrons o Radioisotopes Heavy isotopes that have unstable nuclei - Atomic weighto The average of all the weights of the isotopes Molecules & Compounds - Moleculeso 2 or more atoms joined together by chemical bonds- Compoundso 2 or more different molecules joined together Chemical BondsSolute - Substances that are present in a lower quantity (mixed in) Solvent - Substance that is present in a larger quantity - Interaction of electronso Allow chemical bonds to occur o Electrons are arranged in electron cells  Valence shell – outer most electron cell o Each shell can hold a maximum number of electrons  2 are located in the 1st shell  8 can be held in the 2nd electron shell  18 can be held in the 3rd electron shell  32 can be held in the 4th electron shell - What makes atoms stable? o Are if it has the maximum amount electrons in the valence shello Have 8 electrons in the valence shell o If atoms are not stable They give up, take away, or share electrons with other atoms3 Types of Chemical Bonds (strongest weakest)1. COVALENT BONDS a. Single, double, triple bondsb. When atoms SHARE the electrons c. Polar Covalent Bonds (WATER molecule) i. The electrons spend more of their time near 1 of the atoms than the other ii. Changes shape of molecule iii. Makes the charge of the atom (that it is closest to) more negative iv. The atoms not near the electron forms a more positive chargev. Atoms that have 6 or 7 in their valence shell tend to be more negative d. Nonpolar i. Share the electrons equally ii. Has a linear shape2. IONIC BONDS a. A atom give up an electron (makes it +) i. Another atom gains the electron (makes it -) b. Electrons are TRANSFERRED i. Cations & Anions 1. Cation – positively charged ion2. Anion – negatively charged ion ii. These cations and anions are then attracted to each other c. Ionic compounds dissolve very well in covalent compounds (water)3. HYDROGEN BONDS a. Gives proteins their shapeb. Holds two halves of DNA double helix together c. Not just water Chemical Reactions - Occur when chemical bonds are either made, broken, or changed - Chemical equations show us:o What is involved o What we get out of the reaction - Types o 1.) Synthesis (combination) reactions  Occurs when any kind of bond is created  Underline all anabolic processes- With is the build up of tissues, cells etc. Dehydration & condensation are typical synthesis reactions in the body o 2.) Decomposition reactions Catabolic processes  Hydrolysis – common decomposition in the body o 3.) Exchange (displacement) Reactions Both synthesis and decomposition o 4.) Oxidation – reductions reactions REDOX  electrons exchanged - All reactions can be reversed o Forward reaction= reverse reaction ---- Equilibrium o Bad for chemical reactions in body to reach equilibrium If this happens you’re dead - Rate of chemical reactions – factors: o Temperature Decrease temperature decreases rate of reaction; increase temperature increases rate of reaction o Concentration  Of solutes – higher concentration of solutes: increases rate; lower concentration of solutes: lowers rate o Particle size If have smaller particles – rate happens quicker; because they have more energy  Larger particles – rate happens slowero Catalysts  Things that decrease activation energy required to get chemicalreaction started They help things along but remain unchanged; are neither products or reactants  Proteins act as catalysts – ENZYMES - Are not themselves altered Biochemistry Inorganic compounds - Tend to be simpler - Watero 60-80% of body is water o Most important inorganic compound o High heat capacity Takes a lot of heat (energy) to change temperature of water o High heat of vaporization  Water molecules are separating and going into a gas EX: sweating – draws heat from the body o Is a covalently bond moleculeo Polar molecules Can be a solvent for many other substances because it is polar –attracted to more molecules - Salts- Acids & Baseso Like salts dissolve in water to form electrolytes (can conduct electricity) o Acids  Release H cations when dissolves in water Give up H ions Proton donors  Strong acid- Completely dissociates into its anion and cation - EX – HCl  Has higher concentration of H ions- Lower part of the scale o Bases  Take in H ions  Proton acceptors  Lower concentration of H ions- Higher part of the scale o pH Scale is on a –log base scale lower the pH the higher the H ions  higher the pH the lower the concentration of H ions log scale