CHEMISTRY TO LIFE

Producers Another name for producers? AUTOTROPHS!

Photosynthesis Process of turning light energy from the sun into chemical energy Chloroplasts  organelles where photosynthesis occurs – Contain chlorophyll = a light-absorbing pigment – Light reaction = splits water by using solar energy – Calvin cycle = links carbon atoms from carbon dioxide into sugar (glucose) 6CO 2 + 6H 2 O + the sun’s energy  C 6 H 12 O 6 + 6O 2

Photosynthesis

Consumers What are the different types of consumers? Another name for consumers? HETEROTROPHS!

Respiration Process of releasing the chemical energy from glucose to power life functions C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + ENERGY

Early Earth 4.5 billion years ago, Earth was a hostile place – Severe volcanic and tectonic activity – Intense ultraviolet energy from the sun – No oxygen existed in the atmosphere, until photosynthesis developed in microbes – No life existed

Life’s Origin Hypotheses “PRIMORDIAL SOUP”: HETEROTROPHIC HYPOTHESIS (now less likely to be true) – “Soup” of inorganic chemicals dissolved in ocean’s waters – Amino acids might have formed under these conditions / organic compounds followed including self-replicating RNAs – Heterotrophic  first life forms used organic compounds as energy source – Miller and Urey created amino acids in lab by passing electricity through mixture of water and compounds

Life’s Origin Hypotheses “PRIMORDIAL SOUP”: HETEROTROPHIC HYPOTHESIS (now less likely to be true)

Life’s Origin Hypotheses “SEEDS” FROM SPACE: PANSPERMIA HYPOTHESIS (more plausible than previously thought) – Microbes from elsewhere in solar system traveled on meteorites that crashed to Earth, seeding our planet with life – Thought entering our atmosphere (high temp) would destroy any organisms, but meteorite in 1969 found to have amino acids that survived

Life’s Origin Hypotheses LIFE FROM THE DEPTHS: CHEMOAUTOTROPHIC HYPOTHESIS – First organisms were chemoautotrophs, creating own food from hydrogen sulfide (life originated at deep-sea hydrothermal vents where sulfur was abundant) – Have shown that it is possible to form amino acids and begin reactions that might lead to life under similar high temperature / pressure conditions

Fossils Imprint in stone of a dead organism Fossil record  gives information about the history of past life (shows evidence of mass extinctions… we can learn from the past)

Evolutionary Relationships

Chemistry and the Environment: Exxon Valdez Oil Spill – In March 1989, Exxon Valdez oil tanker struck a reef in Alaska’s Prince William Sound – Spilled 11 million gallons of crude oil (largest oil spill in U.S. history), which coated the Alaskan coast – Killed MANY seabirds, sea otters, harbor seals, and numerous types of fish… DESTROYED PRISTINE ENVIRONMENT!! – Massive clean-up response (skimmed oil from water, soaked it up with materials, dispersed it with chemicals, pressure-washed beaches, burned the oil, etc.)

Chemistry and the Environment: Exxon Valdez Oil Spill

BIOREMEDIATION Attempt to clean up pollution by enhancing natural processes of biodegradation by living organisms