Chapter 4: From Chemistry to Energy to Life www.aw-bc.com/Withgott Chemistry and the Environment conservation of matter atoms protons (+) neutrons electrons (-) Isotopes have a different number of neutrons in the atom – some are radioactive – half-life of minutes to millions of years Ion is an atom that gains an electron (-) or loses one (+) – Ca+2 calcium which has lost 2 electrons Compounds Organic have carbon (C), oxygen (O), hydrogen (H) and nitrogen (N) in them as the core example: CO2 carbon dioxide Inorganic any other compound example: NaCl table salt Solutions mixture of substances – – – air is a solution of gases tap water is a solution of liquids human blood pH 0 - 14 0-7 acid 7 is neutral 7-14 base www.aw-bc.com/Withgottt Macromolecules building blocks of life large in size compared to other simple molecules like water and sugar proteins, carbohydrates, lipids, nucleic acids Synthetic Polymers plastics man-made not present in nature derived from hydrocarbons resist chemical breakdown can create problems in wildlife Compartmentalization of Macromolecules natural macromolecules make up cells, the unit of life, from the simple bacteria to more complex organisms like you and I. Prokaryotes Eukaryotes Energy potential energy: energy present in a molecule kinetic energy: energy produced by the movement of a molecule chemical energy: energy held in the bonds of a molecule Thermodynamics: Energy conservation First Law: energy is not created nor destroyed, its only transformed. – energy in food Second Law: nature of energy will change from more ordered one to a more chaotic one. – decomposition of a dead organism Light Energy Produces Food autotrophs: produce their own food with the use of solar energy known as photosynthesis. Example→plants which become the primary producers 6CO2 + 6H2O → C6H12O6 + 6O2 carbon water glucose oxygen dioxide Cellular Respiration Releases Chemical Energy heterotrophs: consume autotrophs to obtain energy. example→animals which become the primary consumers C6H12O6 + 6O2 → 6CO2 + 6H2O + energy www.aw-bc.com/Withgott Chemosysthesis chemical-bond energy of hydrogen sulfide (H2S) to transform inorganic carbon into organic compounds. Present in bacteria found in the hydrothermal vents at the bottom of the ocean 6CO2 + 6H2O → C6H12O6 + 3H2SO4 Origin of Life Primordial soup: simple inorganic compounds under special conditions formed the first organic compounds. Panspermia hypothesis: microbes from outer space came to contact with earth and evolved. Chemoautotrophic theory: proposed the bacteria from the hydrothermal vents came first. Evolution through the Fossil records comparison of genes Prokaryotes – – history of life bacteria Archaea Eukaryotes protists – plants – fungi – animals THE END – www.aw-bc.com/Withgott