Atoms

Definition/HxPeriodic TableStructure:Protons…+Electrons…-Neutrons…0Isotopes

Mendeleev

Arranged known elements (63) into table by their propertiesPredicted discovery of new elements3 were discovered in his lifetime!

Atomic strucutre

Nucleus contains protons and neutronsElectrons at discrete orbits (clouds) called shells

Atomic Structure…Isotopes

The NucleusNeutronsProtonsElectrons…shells

IsotopesUsually

radioactive“Extra” neutrons

Isotopes & “clocks”

½ life decay can be used as a”tick”Example: Carbon-14Useful in medical:Iodine-131, Oxygen-18

Molecules & Compounds

Molecules Elements compounds

Octet rule? Outer shell e-’sChemical bonds Ionic Covalent Hydrogen

Ionic Bonding

Electrons transferredResult=charged +/-Opposites…?Form polar molecules that often dissolve in water

Covalent Bonding

Electrons shared1, 2 or 3 e- sharedOften nonpolarCommon for organic compounds

Hydrogen bonds

Weak bondStabilizeLiquidsCommon in nonpolar molecules

quiz

Construct a calcium atom…include protons/neutrons and electrons…how many outer shell electrons are there?What happens to outer shell electrons in ionic/covalent bonds?Why are hydrogen bonds important to organic molecules?

Water!!

Water, water everywhere

Liquid…but…Polarity…?…yes!Heat capacityCohesionUniversal solvent

Dissolving

Crystal held together by bondsSurrounded by moving water moleculesInteractions????

Dissolving??

Atoms/molecules isolated and surrounded by hydration “shells”Why important?Solution=solute in solvent

Acids, Bases & Buffers

pH scale…0-7-14Why important?Role of buffers

Why is most of life adapted to acid conditions???

Quiz

Why is water important to life?Why is dissolving important?Why are buffers important to living things?Do you think life could exist without water? Why??

Carbon-based life forms

Why carbon??Some notation…Building organic compounds… Transfer e- transfer Isomerism Condensation… Cleavage…

Carbohydrates

What are they?Uses in body?MonosaccharidesDisaccharidesPolysaccharides

Lipids

Nonpolar…soooo?Fats & fatty acids Structure Saturated Unsaturated (&

poly)

WaxesPhospholipidsSteroids

Protein

Functions…Amino acids…20?Levels of structure Primary… Secondary… Tertiary… Quaternary…

Denaturation…!!

Hair is protein

DNA/nucleic acids

Largest moleculesSimple compositionSome metabolic functionsHereditary informationBrave New World!!

quiz

List the four organic classes of moleculesGive a function for each of the aboveWhy carbon instead of another element?