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Campbell and Reece Chapter 4. ORGANIC CHEMISTRY. Organic Chemistry. study of carbon compounds (most also have hydrogen) range from small molecules (methane has 4 atoms) to very large one (proteins can have thousands of atoms). Major Elements of Life. Carbon Hydrogen Oxygen Nitrogen
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Campbell and Reece Chapter 4 ORGANIC CHEMISTRY
Organic Chemistry • study of carbon compounds (most also have hydrogen) • range from small molecules (methane has 4 atoms) to very large one (proteins can have thousands of atoms)
Major Elements of Life • Carbon • Hydrogen • Oxygen • Nitrogen • Sulfur • Phosphorus
Carbon is very Versatile • because C can form 4 covalent bonds these 6 elements can form an almost limitless # organic molecules
VITALISM • Some credit Hippocrates • Simply stated: there is a life force outside physical & chemical laws
JonsJakob Berzelius • Swedish chemist in early 1800’s • “Organic compounds come from living things” (only ) • so inorganic compounds found only in nonliving things
FredrichWÖhler • German chemist • 1828: synthesized urea in lab (normally made in kidney) • Did not convince Vitalists because he 1 reactant he used came from animal blood
Hermann Kolbe • Student of Wohler • Synthesized urea using only inorganic reactants….. • Crushed Vitalism…..sorry Yoda
Origin of Life on Earth • Stanley Miller, 1953 • Designed experiment trying to re-create conditions on early Earth • Hypothesized : abiotic synthesis of organic compounds possible
Miller’s Experiment • Closed system • Flask of water (early seas) heated • Water vapor rose to another higher chamber containing “atmosphere” • Sparks added (lightening) • “rain” formed, cooled material collected analyzed
Miller’s Conclusion • Complex organic compounds could form spontaneously under conditions thought to exist on early Earth
Miller’s Results • 2008: re-analyzed some samples from Miller’s experiments in the 1950’s • Additional organic compounds identified
Organic Chemistry • Definition changed to: • Study of Carbon Compounds (regardless of origin)
Bonding with Carbon • C has 4 valence e- • Bonds possible: • 4 single covalent bonds • 2 single & 1 double covalent bond • 2 double covalent bonds • 1 single & 1 triple covalent bond
Carbon Skeletons • Carbon chains form the backbone of most organic molecules • These skeletons can be • Straight • Branched
Carbon Skeleton Variation • In rings:
Carbon Skeleton Variation • 1 important source of molecular complexity & diversity that characterizes living organisms
Hydrocarbons • C & H • Major components of petroleum products (fossil fuels) • When organism dies all water soluble compounds wash away as it decays. • Fats stay behind hydrocarbons • Burn fossil fuels because they release a large amount of energy
Isomers • Cpds with same # and types of atoms but they are arranged differently • Different structures behave differently • 3 types: • Structural Isomers • Cis/trans Isomers • enantiomers
Structural Isomers • Differ in covalent arrangements of their atoms • Molecular formula same, structure different
Structural Isomers • # possibilities for different arrangements of atoms increases dramatically as carbon skeleton increases in size
Cis-trans Isomers • aka geometric isomers • Carbons have covalent bonds with same atoms but these atoms differ in their spatial relationship
Cis-trans Isomers • In cis groups are on same side of Carbon • In trans groups are across from each other
Cis-trans Isomers • The difference in cis-trans can dramatically affect the biological behavior of the molecule
Enantiomers • Isomers that are mirror images of each other • Differ in shape due to having asymmetric carbon
Enantiomers • Usually only 1 is biologically active • Other 1 may have much milder effect
Functional Groups • Portion of molecule that participates in chemical reactions in a characteristic way • 7 common, & very important functional groups in organic chemistry
HYDROXYL-OH • Make alcohols • Properties: • Polar • Can for H-Bonds with water (help cpd dissolve in water)
CARBONYL-C=O • Makes: • Ketones: if in middle of molecule • Aldehyde: if at end of molecule • Properties: • can be isomers • ketoses/aldoses
CARBOXYL-COOH • Makes: organic acids • Properties: • Can donate H+ COO- • Mostly found in cells in ionized form (charge of -1) & called a carboxylate ion • In amino acids
AMINO-NH2 • Makes: Amines • Properties: • Acts as a base (can take H+) • Found in cells in ionized form with +1 charge • in amino acids
SULFHYDRYL-SH • Makes: thiols • Properties: • 2 –SH can react forming disulfide bridges • These bridges make hair curly
PHOSPHATE-PO4 • Structure: • 2 O have (-) charge • Makes: • Organic phosphates • Properties: • Makes molecule polar (-1) charge when in middle, (-2) when on end • Can react with water energy
METHYL-CH3 • Makes: • Methylated compounds • Properties: • When attached to DNA, affects expression of genes • Attachment to Testosterone changes biological effect compared to Estrogen (without methyl group)
ADENOSINE TRIPHOSPHATEATP • Made of adenosine + 3 phosphate groups • When 3 phosphates in series, easy to remove 3rd group with water