Origin of Life

• hydrothermal vent- is a hotspring/geyser on the seafloor. It continuously spews super-hot (~400ºC), mineral-rich water that helps support a diverse community of organisms.
• Deep-sea hydrothermal vents form along mid oceanic ridges, the volcanic undersea mountain ranges where new seafloor is created.
• Black smokers - Waters rich in sulfide minerals, superheated waters (approx. 400 deg. C) and is contact between the superheated waters and frigid ocean water results to precipitation of minerals (massive sulfide ore deposits; sometimes gold)
• White smokers - Waters depleted in sulfide minerals, water temperature less than that of the black smokers
• Vent ecosystem - Center of unique ecosystems beneath the seafloor. Depend on microbes that tap into the chemical energy in the vent water
• Extremophiles - convert heat, methane and sulfur compounds into energy through chemosynthesis
• Instead of photosynthesis, vent ecosystems derive their energy from chemicals in a process called what?

  Chemiosynthesis
• What similar reactants are needed by both processes of photosynthesis and chemosynthesis?

  Carbon dioxide, water
• Photosynthesis gives off oxygen gas as a byproduct, while chemosynthesis produces sulfur
• For other chemosynthetic life in cold Methane-Sulfur waters, what is the source of energy aside from hydrothermal vents?

  oil seeps
• In a gradient between the hydrothermal vent water, and the extremely cold water, what is formed between them?

  Organic molecules
• What origin of life proposes that life on earth began as a primordial soup in a lake or pond 4 bya and that chemicals from the atmosphere combined with some form of energy necessary to make amino acids, the building blocks of protein, to create the first primitive organism and start the evolution of life?

  Primordial Soup Hypothesis
• A.I. Oparin (Russian) and J.B.S. Haldane (British): independently proposed similar hypothesis in the 1920s showcasing that a reducing atmosphere and abundant methane and ammonia where ideal for the primordial soup
• MILLER–UREY EXPERIMENT - An experiment that simulated hypothetical conditions of the early Earth, testing earlier hypothesis that conditions on the primitive Earth favored chemical reactions that synthesized organic compounds from inorganic precursors.
• What are the main ingredients for primordial soup?

  Water, methane, ammonia, hydrogen.
• After 1 week, the water in the flask turned into a muddy brown liquid (the primordial soup) containing amino acids, cyanide (HCN) and formaldehyde (H2CO)
• Comets - contain large amounts of complex carbon compounds and provided large supply of complex organic molecules along with water and other volatiles
• Panspermia - Origin of life outside of Earth wherein life in a ready-made form is ubiquitous in the galaxy, brought by comets to planets
• Murchison meteorite - carbonaceous and harbors sugar-related organic compounds providing evidence that another fundamental building block of life might have come from outer space
• What was the first discovery of a sugar molecule in space?

  Glycolaldehyde
• Titan - only satellite in our Solar system that has a thick and extended atmosphere and is Saturn's moon
• Titan - resembles the very young Earth before the appearance of life, when oxygen probably existed in the form of carbon dioxide and methane was abundant.
• Europa - Jupiter's moon, water ice as predominant component on the surface Possible that beneath the surface ice is a layer of liquid water, perhaps as much as 50 km deep, kept liquid by tidally generated heat. From this, we can speculate that the mantle ocean hosts a modest biota
• Phoenix Mission - NASA's mission to build a spacecraft that could fly to Mars and return to Earth; study the history of water in the Martian arctic; and search for evidence of a habitable zone and assess the biological potential of the ice-soil boundary.