Chemistry Alive: Review of Basic Concepts It is soooooooo important that you understand so please ask questions. I will post this slides to my Brookwood teacher page today. – Select Crawford from drop down and go to handouts

Concepts of Matter Anything that occupies space and has mass Mass remains constant but weight varies with gravity Matter can be seen, smelled and/or felt Solid, liquid or gas Matter can be changed physically or chemically Liquids conform to the shape of the container Gas- no definite shape nor definite volume

Composition of Matter Matter is composed of substances called elements Elements cannot be broken down into simpler substances by ordinary chemical methods 96 % of body weight is made up of 4 elements Carbon, Oxygen, Hydrogen, Nitrogen Atoms are the building blocks of elements- identical particles

Elements and Atoms Pure substances like carbon, hydrogen and oxygen that are composed of only one type of atom are classified as elements. Element is designated by a one- or two- letter chemical shorthand called the atomic symbol, C is for Carbon, Na is for sodium Atom is derived from the Greek word meaning “incapable of being divided” If an atom is split into its sub particles it loses the unique properties of its element

ElementAtomic Symbol % Role Oxygen O65 Component of organic and inorganic molecules. Oxidation of glucose Carbon C18.5 Primary element Of all organic molecules Hydrogen H9.5 Ionic form influences the pH of body fluids. Component of most organic molecules Nitrogen N3.2 Component of proteins and nucleic acids Elements of Life

ElementAtomic Symbol %Role Calcium Ca 1.5Salt in bones and teeth; ionic form required for muscle contraction, neural transmission and blood clotting PhosphorusP1.0Salt, in combination with Ca in bone and teeth. Nucleic acids, proteins; forms part of ATP PotassiumK0.4Ionic form major intracellular cation (+) ;nerve impulses and muscle contraction SulfurS0.3Component of contractile proteins of muscle SodiumNa0.2Major extra cellular cation; water balance, nerve impulses and muscle contraction

ElementAtomic Symbol %Role ChlorineCl0.2Major extra cellular anion(-) Magnesiu m Mg0.1Bone; cofactor for enzyme activity IodineI0.1Needed to make functional thyroid hormones IronFe0.1Component of functional hemoglobin molecule Trace elements less than 0.1 %: Cr, Co, Cu, Fl, Mn, Mo, Se, Si, Sn, V, Zn; Many found as part of enzymes or required for enzyme activation

Molecular Substances I.When two or more atoms are chemically bonded a molecule is formed. II.Two atoms of the same element bond together an element is produced. I.e. O 2, H 2 III.Two or more different atoms form molecules of a compound, CH 4 IV.Molecule is the smallest part of a compound that retains the features of that compound

Compounds A compound is a substance made from two or more elements which have reacted chemically with each other. For example : The element sodium is a highly reactive metal and the element chlorine is a yellow-green poisonous gas (non- metal). When the two react together, they form a compound called sodium chloride. Sodium chloride is common salt, which you eat with food.

Chemical Bonds IonicIonic –Electron transferred CovalentCovalent –Electron shared Hydrogen (polar covalent)Hydrogen (polar covalent) –Electron shared unequally

Chemical Reactions When reactions take place, there is an exchange of energy. Whenever chemical bonds are broken, energy is released. When new bonds are formed, energy is stored. Sometimes [when the energy stored in the new bonds of the products is less than the energy released from the reactants] energy is released during a reaction. This energy may be given off as heat, or it may be used to do work. Sometimes, the products of the reaction store more energy in their chemical bonds than the reactants had stored. This stored energy can be held for later use. reaction where reactants and products are balanced C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + ATP

Chemical Reactions All chemical reactions involve atoms trying to get a full outer shell of electrons. When an atom reacts with another atom, it will either 1. Lose electrons to form a stable positive ion. 2. Gain electrons to form a stable negative ion. 3. Share electrons to form a stable molecule. Key to chemical reactivity is the rule of 8s. ( Octet Rule)

Synthesis reactions As an example of a synthesis reaction : Ca + S > CaS The + sign means "reacts with" or "combines with" and the arrow indicates "to form".

Synthesis Reactions: Summary Involve bond formationInvolve bond formation Energy-absorbing reactionsEnergy-absorbing reactions Underlie all anabolic (constructive) activities in body cellsUnderlie all anabolic (constructive) activities in body cells Growth and repair of worn-out or damaged tissuesGrowth and repair of worn-out or damaged tissues

Decomposition reactions An example of a decomposition reaction is : The products of this decomposition reaction have quite different chemical properties to the initial compound.

Decomposition Reactions Bonds are brokenBonds are broken Chemical energy is releasedChemical energy is released Catabolic (destructive) processesCatabolic (destructive) processes Molecule-degrading reactionsMolecule-degrading reactions Digestion of food into building blocksDigestion of food into building blocks Breakdown of glycogen to release glucoseBreakdown of glycogen to release glucose

Exchange Reactions Involves both synthesis and decomposition reactionsInvolves both synthesis and decomposition reactions Bonds are both made and brokenBonds are both made and broken ATP reacts with glucose forming glucosephosphate and ADPATP reacts with glucose forming glucosephosphate and ADP AB + C AC + BAB + C AC + B AB + CD AD +CBAB + CD AD +CB

Chemical Reactions If a reaction releases energy it is exergonic If a reaction absorbs energy it is endergonic Catabolic and oxidative reactions are for the most part exergonic

4 Factors influencing chemical rxns Temperature: An increase in temperature increases the kinetic energy therefore the reactions are quicker Amount: As the concentration of reactants decline we reach chemical equilibrium Size: Smaller particles move faster, hence faster reactions Catalysts: increase a reaction without being used up, enzymes