AP Biology For today  In your notes, try to draw out the carbon cycle. Remember to indicate the different ways carbon cycles between the ground and the atmosphere (think about the relationship between plants and animals and industrial processes).

AP Biology Ch. 4: Chemistry of Carbon Building Blocks of Life

AP Biology Why study Carbon?  All of life is built on carbon  Cells  ~72% H 2 O  ~25% carbon compounds  carbohydrates  lipids  proteins  nucleic acids  ~3% salts  Na, Cl, K…

AP Biology Chemistry of Life  Organic chemistry is the study of carbon compounds  C atoms are versatile building blocks  6 valence e-, 2 in 1 st shell making it full, 4 in 2 nd shell, each available for bonding  4 stable covalent bonds HH C H H

AP Biology Complex molecules assembled like TinkerToys

AP Biology Hydrocarbons  Combinations of C & H  non-polar  not soluble in H 2 O  hydrophobic  stable  very little attraction between molecules  a gas at room temperature methane (simplest HC)

AP Biology Hydrocarbons can grow

AP Biology Basic Naming Rules of Hydrocarbons # of Carbons in backbone Name in prefix 1Meth- 2Eth- 3Prop- 4But- 5Pent- 6Hex- 7Hept- 8Oct- 9Non- 10Dec-  Alkanes  Have single bonds  Denoted by suffix “-ane”  Formulas fit a C n H 2n+2 rule  Alkenes  Have double bonds  Denoted by suffix “-ene”  Formulas fit a C n H 2n rule  Alkynes  Have triple bonds  Denoted by suffix “-yne”  Formulas fit a C n H 2n-2 rule

AP Biology Isomers  Molecules with same molecular formula but different structures (shapes)  different chemical properties  different biological functions 6 carbons

AP Biology Form affects function  Structural differences create important functional significance  amino acid alanine  L-alanine used in proteins  but not D-alanine  medicines  L-version active  but not D-version  sometimes with tragic results… stereoisomers

AP Biology Form affects function  Thalidomide  prescribed to pregnant women in 50s & 60s  reduced morning sickness, but…  stereoisomer caused severe birth defects

AP Biology Diversity of molecules  Substitute other atoms or groups around the carbon  ethane vs. ethanol  H replaced by an hydroxyl group (–OH)  nonpolar vs. polar  gas vs. liquid  biological effects! ethane (C 2 H 6 ) ethanol (C 2 H 5 OH)

AP Biology Functional groups  Parts of organic molecules that are involved in chemical reactions  give organic molecules distinctive properties hydroxyl amino carbonyl sulfhydryl carboxyl phosphate  Affect reactivity  makes hydrocarbons hydrophilic  increase solubility in water

AP Biology Viva la difference!  Basic structure of male & female hormones is identical  identical carbon skeleton  attachment of different functional groups  interact with different targets in the body  different effects

AP Biology Hydroxyl  –OH  organic compounds with OH = alcohols  names typically end in -ol  ethanol

AP Biology Carbonyl  C=O  O double bonded to C  if C=O at end molecule = aldehyde  if C=O in middle of molecule = ketone

AP Biology Carboxyl  –COOH  C double bonded to O & single bonded to OH group  compounds with COOH = acids  fatty acids  amino acids

AP Biology Amino  -NH 2  N attached to 2 H  compounds with NH 2 = amines  amino acids  NH 2 acts as base  ammonia picks up H + from solution

AP Biology Sulfhydryl  –SH  S bonded to H  compounds with SH = thiols  SH groups stabilize the structure of proteins

AP Biology Phosphate  –PO 4  P bound to 4 O  connects to C through an O  lots of O = lots of negative charge  highly reactive  transfers energy between organic molecules  ATP, GTP, etc.

AP Biology Macromolecules Building Blocks of Life

AP Biology Macromolecules  Smaller organic molecules join together to form larger molecules  macromolecules  4 major classes of macromolecules:  carbohydrates  lipids  proteins  nucleic acids

AP Biology H2OH2O HO H HH Polymers  Long molecules built by linking repeating building blocks in a chain  monomers  building blocks  repeated small units  covalent bonds Dehydration synthesis

AP Biology H2OH2O HO H HH How to build a polymer  Synthesis  joins monomers by “taking” H 2 O out  one monomer donates OH –  other monomer donates H +  together these form H 2 O  requires energy & enzymes enzyme Dehydration synthesis Condensation reaction You gotta be open to “bonding!

AP Biology H2OH2O HOH H H How to break down a polymer  Digestion  use H 2 O to breakdown polymers  reverse of dehydration synthesis  cleave off one monomer at a time  H 2 O is split into H + and OH –  H + & OH – attach to ends  requires enzymes  releases energy Breaking up is hard to do! Hydrolysis Digestion enzyme

AP Biology Carbon Cycle

AP Biology Carbon Carbon exists in the nonliving environment as:  Carbon dioxide (CO2)  Carbonic acid ( HCO 3 − )  Carbonate rocks (limestone and coral = CaCO 3 )  Deposits of Fossil fuels  Dead organic matter

AP Biology Organic Carbon  Hydrocarbons: CH 4  Carbohydrate: CH 2 O

AP Biology Inorganic carbon  Carbon Dioxide: CO 2  Calcium Carbonate: CaCO 3 Mandale Limestone Quarry

AP Biology Carbon reservoirs

AP Biology Carbon reservoirs The atmosphere. The biosphere (include fresh water systems and non-living organic material, such as soil carbon). The oceans ( including dissolved inorganic carbon and living and non-living marine biota). The lithosphere (sediments, Earth core including fossil fuels).

AP Biology Carbon Cycle

AP Biology Carbon is released into the atmosphere in several ways Respiration by plants and animals. Decay of animal and plant matter. Combustion of organic material Production of cement. The ocean releases CO2 into the atmosphere. Volcanic eruptions and metamorphism

AP Biology Carbon is taken from the atmosphere in several ways  Photosynthesis.  The oceans when the seawater becomes cooler, more CO 2 dissolve and become carbonic acid.  In the upper ocean areas organisms convert reduced carbon to tissues, or carbonates.

AP Biology Photosynthesis  CO 2 + H 2 O + sunlight  CH 2 O + O 2

AP Biology Respiration  CH 2 O + O 2  CO 2 + H 2 O + energy

AP Biology Combustion or Oxidization of hydrocarbon CH O 2  CO H 2 O + energy

AP Biology Human Impacts on the Carbon Cycle Burning fossil fuels have serious impact on the carbon cycle.

AP Biology Fossil Fuel 86% of global primary energy consumption is fossil fuels.

AP Biology Fossil Fuels Petroleum Natural Gas Coal

AP Biology CO 2 Concentration Pre-Industrial value: 280 ppm (600 billion tons) Current value: 395 ppm (850 billion tons) Critical value: 560 ppm (1200 billion tons)