Basic Chemistry Chapter 2

MATTER & ENERGY Matter Anything that occupies space and can be weighed Chemistry examines the nature of matter Energy No mass Ability to do work Matter is the substance that is moved by energy

Matter Building blocks: solid, liquid, gas Physical change –nature of substance is unchanged Chemical change –nature of substance is changed

ENERGY No mass We measure the effect of energy on matter Two types: Kinetic and Potential

ENERGY Forms: Chemical -stored within bonds, released as heat Electrical -movement of charged partials (e-) Mechanical -direct movement of matter Radiant -electromagnetic waves Energy is converted from one form to another, any not used is released as heat.

COMPOSITION OF MATTER Elements Atoms Opposites attract! Protons (p+) –positive charge Neutrons(n0) –neutral or no charge Electrons (e-) –negative charge Opposites attract! http://www.chemicalelements.com/

ELEMENTS OF THE HUMAN BODY

ATOMS Orbital Model –electron cloud Atomic number –number of protons Atomic mass –sum of all protons and neutrons Isotopes –vary in number of neutrons Radioisotopes –radioactivity, heavy isotopes

CHEMICAL BONDS & REACTIONS Molecules, Compounds, Reactions, OH MY! Molecules =same Compounds =different Reactions =associations or dissociations of atoms Bonds form between molecules and compounds Energy relationships

CHEMICAL BONDS Bonds are energy relationships Opposites attract while “like” or same repels Role of electrons Occupy fixed regions called electron shells or energy levels Valence shell electrons participate in bonds

ENERGY LEVELS

ENERGY LEVELS Valence Shells (energy levels) Outer shell If fewer than 8 electrons will try to: share, gain, lose

ENERGY LEVELS

CHEMICAL BONDS Ionic –one atom gains electron and second loses Covalent –electrons are shared between atoms Hydrogen –form bridge between two electrically negative atoms

CHEMICAL REACTIONS Synthesis –larger molecule formed Decomposition –larger molecule is degraded Exchange –synthesis and decomposition; switch

BIOCHEMISTRY Inorganic compounds do not contain carbon atoms Water, salts (electrolytes), acids and bases Organic compounds contain carbon atoms Carbohydrates, lipids, proteins and nucleic acids

INORGANIC COMPOUNDS Water –thermoregulatory, universal solvent, reactivity, cushioning, lubrication Salts –cations other than H+, electrolytes Acids –H+, proton donors Bases –OH-, proton acceptors pH –concentration of acid; [protons] pH 7 =1 x 10-7 pH2 =1 x 10-2 pH12 =1 x 10-12

pH 7 =1 x 10-7=0.0000007 pH6 =1 x 10-6 =0.000006 pH1 =1 x 10-1 =0.1 pH14 =1 x 10-14 =0.000000000000014

ORGANIC COMPOUNDS Large, complex molecules Functional groups are reactive parts Monomers combine to form polymers Carbohydrates, Lipids, Proteins, Nucleic Acids, ATP

CARBOHYDRATES “Hydrated Carbon” Monosaccharides are building blocks Disaccharides –double sugars Polysaccharides –branching chains

LIPIDS More carbon & hydrogen than oxygen Insoluble in water Saturated or unsaturated Triglycerides –fatty acids + glycerol Phospholipids –contain phosphorus Steroids –flat with interlocking rings

PROTEINS Amino acids are building blocks Amine + acid group + functional group (R) Most are complex in structure Tertiary Primary Secondary

PROTEINS Fibrous or Globular Function depends on shape Enzymes (end in –ase)

NUCLEIC ACIDS Building blocks are nucleotides Code for genes 5 types: adenine, guanine, cytosine, thyamine, uracil Deoxyribonucleic Acid (DNA) & Ribonucleic Acid (RNA)

ADENOSINE TRIPHOSPHATE Chemical energy Adenine base + ribose sugar + 3 phosphates Phosphate bonds are high energy