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Short answer Plants release O2, because it is not an energy source. Instead, it is used to free energy from energy-rich organic compounds. Background Plants are solar powered. They release oxygen as a waste product during carbon fixation. Carbon fixation is basically the storage of solar power into carbon-bonds in glucose, a process referred to as ...


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As far as I can understand your question, you wish to know why a plant cell consumes ATP to produce glucose when it can directly use the ATP as an energy molecule. ATP is an energy currency and is required in different biochemical pathways. However, it is not a good energy storage molecule. Following are the reasons why production of an energy molecule ...


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It depends, but you're going to die. Specifically, it depends on how fat you are. Even Andreas Munzer is going to die. At only 3% body fat, burning all his fat (9kcal/g) would "only" increase his internal body temperature by 270 degrees C. Factoring in the energy required to boil off his body moisture and adding in body heat leaves Andreas at ~200 C or so (...


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For skeletal muscles, you'll find a discussion in the Physics SE: http://physics.stackexchange.com/questions/1984/why-does-holding-something-up-cost-energy-while-no-work-is-being-done To make things short: while holding a position, muscles need to maintain a given length. However, internally, the muscle looks like a collapsible array of filaments, with ...


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The short answer: no. First, let's get an understanding of the cell cycle control system, as there are some important molecules involved in this system that regulate mitosis. Think of the control system as a series of stoplights: as you mention, there is one stoplight at the G2 phase. There are two additional checkpoints: one at G1 and one in the M (mitotic) ...


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What you have asked for is a causal answer to correlated findings. There is no cause-effect evidence (at least from my searching) showing low cholesterol will indeed cause stroke. Associations like this are dangerous in the sense that we shouldn't think that one causes the other. But, we can speculate on how they are linked, which is always fun. I'll be ...


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Whether wireless power transfer is safe depends on the type of power transfer. Inductive coupling is generally safe, but only works across small distances (i.e., millimeters to centimeters). The other option is far-field or radiative technology, where either visible light (from lasers) or microwaves are used. The latter has not been applied much, some uses ...


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It is yet to be discovered by scientists. But there is a new study that finds that brain cells called astrocytes supply the urge to sleep by releasing adenosine a chemical known to have sleep-inducing effects. The chemical accumulates in the brain during waking hours, eventually helping to stimulate the unique patterns of brain activity that occur during ...


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In a very simplified explanation - the body usually picks the process which is easiest/ fastest which would be to absorb the glucose then the fat would be used for energy as this takes longer to digest and absorb because it is a relatively complex molecule which also requires bile to emulsify it. Starchy/ high glucose products will already be broken down ...


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ATP is adenosine 5'-triphosphate, a molecule consisting of the base adenine attached to which is attached a ribose (at its 1 position) and (at its 5 position) three phosphates, alpha-, beta- and -gamma (see edited image from Wikipedia below). The (Gibbs) free energy of hydrolysis of the phosphoanydride bonds between the gamma and beta phosphates and betweeen ...


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Points to bear in mind That the biological coupling of an energetically favourable and unfavourable reaction (I would avoid using the term spontaneous†) is done through a composite reaction involving all the components of the two separate reactions. The reactants and products are the same as in the sum of the separate reactions — so it is valid to ...


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Keep in mind that there needs to be an enzyme present to "couple" two reactions. You can imagine it like the energy from the ATP hydrolysis pushing the enzyme to a high energy state, and from that high energy state the enzyme can push the secondary reaction against the equilibrium. You could do this, and there might even be examples (maybe for some ...


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This is an interesting question (I really mean this — see below), for which a straight answer is remarkably difficult to find on the web. When I googled for it I got pages with statements that obligate anaerobic bacteria still had the electron transport chain (ETC) and ATP synthase as there were different electron acceptors other than oxygen. Yes, we know ...


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Anaerobic respiration does not completely oxidize the glucose, and as a result, pyruvate is not completely broken down, yielding fewer ATP molecules, and there are leftover molecules: lactic acid in animals and ethanol in yeast. This is because anaerobic respiration does not utilize oxygen, which is required for the electron transport chain, where most of ...


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1) Yes, most cells in the body derive energy from oxidative metabolism, unless oxygen is not available for some reason. There are some exceptions, for example red blood cells lack mitochondria and so have no respiration, and various types of rapidly proliferating cells such as activated immune cells have high glycolysis and lactate production (for reasons ...


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What you're describing is a phototrophic biofilm microbial fuel cell! They're pretty neat. Essentially the sun powers the bacteria and the bacteria in the anaerobic side passes electrons through the graphite electrode to use oxygen at the cathode. There's another explanation here. You could also "unfold" cyanobacteria and layer them and you'd probably get ...


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You should note that even in pure mechanical examples, the energy consumed may not be equal to work done because some energy is also used up in countering the frictional force. In your example you consider an object kept on a wooden table and in this case the weight is balanced by the reaction force by the table. You have not considered the material ...



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