Chemistry of Life

How small is an atom?  Placed side by side, 100 million atoms would make a row only about 1 centimeter long About the width of your little finger

Atoms- basic unit of matter Smallest particles of elements ChargeWeightLocation Protons: +YesNucleus Neutrons: noneYesNucleus Electrons:-NoOrbitals

Elements Cannot be reduced to simpler components

Isotopes Atoms of the same element that differ in their numbers of neutrons All isotopes of that element still have the same properties

When will atoms react?  To gain Electrons  To lose Electrons  To share electrons

Molecules 1.Combinations of atoms 2.Joined by chemical bonds - covalent

Types of Chemical Bonds  Ionic Bonds – gain or lose e-  Covalent Bonds – share e-  Polar  Non-polar  Hydrogen Bonds - general attraction between partial charges of two different molecules

Ionic Bonds : Losing or Gaining e- NaCl

Covalent Bonds: Share Electrons Non-Polar Covalent: neither nucleus exerts more pull on shared electrons

Polar Covalent Bond Atoms share electrons unequally

Hydrogen Bonds (-) (+) (-)

Hydrogen Bonds Possible with polar molecules Easily broken and reformed Give water special properties

Cohesion vs. Adhesion  Cohesion – the attraction between molecules of the same substance  Adhesion – attraction between molecules of different substances

Cohesion  Water is extremely cohesive b/c of H bonding

Adhesion

Water – More…  Found to be part of a solution – where one or more substances are evenly distributed in another substance  Solute – the substance that is dissolved  Solvent – the substance in which the solute is dissolved

Still more about H 2 O  Acids, Bases, and pH  pH – determined by the concentration of H + ions  H 2 O H + + OH - A water molecule can react to form ions

pH  Acid Solutions – contain more H + ions (pH < 7)  Base Solutions – contain more OH - ions (pH>7)

Organic Compounds (C)  Carbohydrates  Lipids  Nucleic Acids  Proteins

Carbohydrate s C:H:O 1:2:1 ratio Monosaccharide s- glucose, fructose Disaccharide – sugar Polysaccharide – starch, cellulose Storing energy Structure in plants Lipids 3 fatty acids 1 glycerol Fats, oils, waxes, and steroids Store energy Pigments Cell Membrane Messages in body Proteins Amino acids EnzymesCollagenAntibodies Structural component Chemical reactions Nucleic acids NucleotidesDNARNA Hereditary info Enzymes and messages Group Name Chemical CompositionExamplesFunction in Living Things

Saturated vs. Unsaturated Fats

 Nucleic acids include RNA and DNA  RNA- Ribonucleic Acid  DNA- Deoxyribonucleic acid  Polymers made up of repeating monomers called nucleotides. NUCLEIC ACIDS

 5-Carbon Sugar  Phosphate Group  Nitrogen-containing base NUCLEOTIDES 3 Main Components:

Nucleotides: Important Energy Storage Molecules  ATP: acts like cell’s battery, providing energy for most activities.