That doesn't mean that CO2 was always good, Hank, as you seem to imply when suggesting that no action was needed to curb global warming. We SHOULD act on the rise of greenhouse gases in the atmosphere.
Cheers! Sam Carana On Nov 18, 12:35 pm, "Henry Kroll" <[EMAIL PROTECTED]> wrote: > Hi Sam. You might like the following knowledge post. > > *HOW NONCYCLIC PHOTOSYNTHESIS JUMPSTARTED LIFE, HILLARY CLINTON AND > EVERYTHING THAT FILLS A NICH.* > > * True plants use carbon dioxide and water (along with nitrogen > and phosphorus from the soil) to make organic compounds and produce oxygen > as a waste product. When the plant needs to use any of the energy it stored, > it uses oxygen to "burn" its fuel, generating water and carbon dioxide as > byproducts of that process. * > > * To take advantage of the energy stored in the plants, animals > eat the plants directly or eat other animals that do. Like the plants, they > use oxygen during metabolism and produce waste water and carbon dioxide. > Both plants and animals need additional water for a variety of functions: > For example, the transport of nutrients up from the roots is powered by the > evaporation of water from the leaves and animals use water to regulate > temperature through evaporative cooling and to dispose waste products. A > small fraction of the earth's living things are anaerobic or harvest > inorganic chemical energy, and so do not fit into this cycle.* > > * * > > * ENERGY CYCLE IN PLANTS* > > * The photon energy: "sunlight" activates electrons, which are > removed from the chlorophyll before they can reemit that energy. These > "excited" electrons are used to charge a membrane battery, which is used to > make the energy transfer compound, adenosine triphosphate (ATP). In the > process the energized electrons, having been activated days or even years > earlier, lose their energy and are discarded in energy poor carbon dioxide. > The ATP is used as a carrier for the electron energy. Every organism faced > nutrient poor conditions and so for every 99.9 percent of new life forms > that evolved only one-tenth of one percent survived while all the rest are > now extinct. --James L. Gould, Carol Grant Gould* > > * It was the unique property of water with two hydrogen atoms > each with a positive charge and one oxygen atom with a negative charge > referred to as nonpolar molecules that allow weak electro static > associations (hydrogen bonds). Their unique geometry allowed the > self-repairing, bilayer membrane of the living cell. Modern cells protect > themselves from the environment with bilayer membranes to which specific > chemical doors and pumps have been added to help control molecular > in-and-out traffic.* > > * Hydrogen Cyanide, for example, is readily formed from ammonia > and methane and then converted into the nucleotide adenine, which is also > the backbone of ATP. –Chemical Evolution and the Origin of Life, By Richard > E. Di ckerson; Scientific American, September, 1978* > > * Many meteorites and comets contain abundant inorganically > formed organic compounds. Natural selection must have been at work from the > very onset, favoring liposomes with the most useful chemistry favoring those > with the most useful building blocks and excluding those that might be > toxic. At this point in time most organisms were autotrophs—that is, > creatures that took energy or energy-rich materials from the nonliving world > around them—as apposed to heterotrophs, which eat other organisms (you).* > > * The next step in the evolution of living organisms was the > development of cyclic photosynthesis—cyclic because the electron energized > by an incoming photon from the sun is quickly returned to the chlorophyll > molecule from which it came. Chlorophyll is embedded in a membrane along > with the enzymes that steal the activated electron and harvest its energy; > that energy is used to charge the membrane, and the electrostatic potential > created is later employed to make ATP.* > > * It takes about two photons to charge the membrane; enough to > make one ATP, and since photons are free, life must suddenly have been > released from dependence on inorganic nutrients synthesis: with > photosynthesis! Suddenly there was enough ATP to generate nutrients from > simple chemicals like carbon dioxide and ammonia!!! There are still bacteria > that employ only cyclic photosynthesis. * > > * * > > * There still wasn't enough ATP available to store large supplies > of sugars and starches to give evolution a much needed boost so nature > invented the noncyclic process which created eight times more ATP than the > cyclic process. In that process the electron energy is boosted in two steps, > and so much extra charging and other work is wrung from its energy that > eight ATP's can be made from two activated electrons because the electron is > not returned to the chlorophyll but is handed to an energy-storage molecule > instead; the missing electron is obtained by splitting water, which > generates oxygen as a waste product.* > > * To put it another way, the electron end up in a multipurpose > energy compound that can be used directly to power carbon fixation to charge > the membrane for subsequent ATP production. The missing electron in the > first chlorophyll is replaced with one obtained by splitting water, a > process that liberates oxygen. * > > * Most photoautotrophs (all true plants) use the more efficient > noncyclic process with the eight-fold increase in energy production.* > > * Because eight times more ATP was being produced by all the > plants they were able to create more energy storage in the form of > carbon-based, starches and sugars. The noncyclic process not only created > more free oxygen it also allowed millions of other life forms to evolve to > feed on the extra, eight-fold energy created by this process. This is why we > have coal, oil and limestone on Earth plus myriads of other oxygen-breathing > animals like Hillary Clinton.* > > * * > > * --The Assembly of Cell Membranes by Mark S. Bretscher; > Scientific American, October 1985* > > * --The Photosynthetic Membrane by By Kenneth R. Miller > Scientific American, October 1979* > > * --Molecular Mechanisms of Photosynthesis by Douglas C Youvan > and Barry L. Marrs; Scientific American, June 1984* > > * --Cytochrome C and the Evolution of Energy Metabolism, by > Richard E. Dickerson, Scientific American, March 1980 Offprint 146* > > * Me: Captain Hank Kroll, navigatorwww.alaskapublishing.com* > > * * > > * * > > * **WHEN DID EARTH GET A 28% OXYGEN-RICH ATMOSPHERE?* > > It is generally believed that life on Earth probably wouldn't > have developed if the early atmosphere had been oxygen rich. Photosynthesis > bacteria were surely not the first living organisms, but the history of life > in the period that preceded their appearance is still obscure. What little > information can be inferred about early earth is consistent with the idea > that the environment was then largely anoxic (without oxygen). One tentative > line of evidence rests on the assumption that among organisms living today > those that are simplest in structure and in biochemistry are probably the > most closely related to the earliest forms of life. Those simplest organisms > are bacteria of the clostridal and methanogenic type, and they are all > obligate anaerobes. > > Somewhat later such bacteria gave rise to the first organisms > capable of aerobic photosynthesis, the precursors of modern cynaobacteria. > For the anaerobic photosynthetic bacteria the molecular oxygen released by > this mutant strain was a toxin, and as a result the aerobic > photosynthesizers were able to supplant the anaerobic one in the upper > portions of the mat communities. The anerobic species became adapted to the > lower parts of the mat, where there is less light but also a lower > concentration of oxygen. > > The anaerobic nature of bacterial photosynthesis seems to > present a paradox: photosynthetic organisms thrive where light is abundant, > but such environments are also generally ones having a high concentration of > oxygen, which poisons bacterial photosynthesis. These contradictory needs > can be explained if it is assumed that anaerobic photosynthesis evolved > among primitive bacteria early in the Precambrian, when the atmosphere was > essentially anoxic. The photosynthesizers could thus have lived in mat-like > communities in shallow water and in full sunlight. > > The several groups of photosynthetic bacteria differ from one > another in their pigmentation, but they are alike in one important respect: > unlike the photosynthesis of cyanobacteria and eukaryotes, all bacterial > photosynthesis is a totally anaerobic process. Oxygen is not given off as a > byproduct of the reaction, and the photosynthesis cannot proceed in the > presence of oxygen. Whereas oxygen appears to be a requirement of green > plants for the synthesis of chlorophyll, oxygen inhibits the synthesis of > bacteriochlorophylls. > > It is argued that oxygen must have been freely available by the > time the first eukaryotic cells appeared, probably 1,400 to 1,500 million > years ago. Hence, the proliferation of cyanobacteria that released the > oxygen must have take place earlier in the Precambrian. How much earlier > remains a question. The best available evidence bearing on this issue comes > from the study of sedimentary minerals, some of which may have been > influenced by the concentration of free oxygen at the time they were > deposited. In recent years a number of workers have investigated this > possibility, most notably Preston E. Cloud, Jr., of the University of > California at Santa Barbara and the U. S. Geologic Survey. > > One mineral of significance in this argument is uraninite (UO2), > which is found in several deposits that were laid down in Precambrian > streambeds. In the presence of oxygen, grains of uraninite are readily > oxidized to U3O8 and are thereby dissolved. David E. Grandstaff of Temple > University has shown that streambed deposits of the mineral probably could > not have accumulated if the concentration of oxygen was greater than about 1 > percent. Uraninite-bearing deposits of this type are found in deposits older > ... > > read more » --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Epistemology" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/epistemology?hl=en -~----------~----~----~----~------~----~------~--~---
