Photosynthesis MCQs - Simplified Biology
Photosynthesis (Simplified) by Joel Hickey on Prezi
Obviously, if we think of being grateful for natural phenomena such as the glory of the warm sun each day and the benefit of rain on fertile soil, we should be grateful indeed for the second law. How could we overvalue the enormous diversion of energy that we are able to achieve from the dispersal of energy that the second law favors when we burn fossil fuels? Coal, and especially petroleum-sourced fuel in cars, planes, trucks, earth-movers, trains, ships and electrical power plants are the life-blood, arms, and legs and support of the nervous system of modern society. Of course, we are not able to divert more than a portion of the energy obtained from combustion for our use. Some of any energy dispersion continues immediately on its way to complete dissipation in the environment and ultimate loss to outer space. Most energy not "dammed" by synthesis of new higher energy long-lived compounds (as in photosynthesis) but just used in moving cars or similar temporary functions is merely dispersed later than the waste heat lost from the tailpipe following the initial explosion of the fuel. The second law is often delayed but it is never violated.
4 Simple Steps - Photosynthesis 4 kidz - Google Sites
This oxidation process occurs in astoundingly complex ways and in many steps (so any energy that is spread out as heat is slowly and moderately released, unlike the seemingly instant "one-step" explosive dispersal of energy when gasoline reacts with oxygen). Furthermore, any heat that is dispersed in our bodies is not wasted because it keeps our bodies warm to function optimally even in a cold environment. Some of the energy flowing downhill from food oxidation is captured by "coupled reactions" so that a medium energy substance, ADP, is raised in energy to become a greater energy-containing substance like ATP. ATP is in every cell in our bodies to disperse energy for a multitude of different reactions while it becomes ADP and then is regenerated by a coupled reaction. Of course, the storage of ATP is contrary to the predictions of the second law, but we know how it 'beats' the second law: :The energy within the bonds of those ATP molecules and similar varieties is kept from being dispersed by activation energy barriers until, of course unknown to us, our cells need it for some action. ATP and similar energy-storage sources are what give us the instant conscious choice of using our arm muscles for work or our eye muscles for looking in a particular direction — or our brain for thought. Many of our ~30,000 chemical substances and the complex cells from which they are made must continually be destroyed and the residues excreted as new ones are synthesized. (For one example, there are about 250 million hemoglobin molecules in each red blood cell. Every hemoglobin has four iron atoms that are responsible for capturing oxygen in our lungs, transporting it to all the cells of our bodies and releasing it there to produce energy via an oxidation process. A person of average weight synthesizes approximately 500 trillion molecules of iron-containing hemoglobin per second in the bone marrow. The same number of hemoglobin molecules are destroyed each second and then excreted as part of fecal matter giving it the color of one form of iron oxide (rust.) There cannot be minutes in which oxygen is not supplied to the energy-requiring cells of the heart or pumped to the energy-requiring brain: we die from a heart attack if adequate oxygen isn't given to its cells and the brain will either be permanently damaged or, if too many minutes elapse without oxygen for energy dispersal and ATP synthesis, death results.. The second law — or better, the energy flow predicted by the second law — is essential to all life.