Carbon dioxide fixing

The specific carbon dioxide-fixing mechanism used by a plant will affect the efficiency of photosynthesis, so from an energy utilization standpoint, it... 

Rutherford found that when a mouse was left in a confined volume of air until it died, one-sixteenth of the volume disappeared and that when the remaining air was treated with alkali, it, in turn, lost one-eleventh of its volume. After thus removing the carbon dioxide ( fixed, or mephitic, air ) and most of the oxygen, he studied the properties of the residual gas. He found it very difficult to completely saturate air with phlogiston" (to remove all the oxygen), for after a mouse had died... 

Scottish chemist, physicist, and physician. Professor of chemistry at Glasgow. He clearly characterized carbon dioxide ( fixed air ) as the gas which makes caustic alkalies mild, and distinguished between magnesia and lime. He discovered the latent heats of fusion and vaporization, measured the specific heats of many substances, and invented an ice calorimeter. 

Cavendish prepared the gas by passing atmospheric air repeatedly over red hot charcoal and removing by means of caustic potash the carbon dioxide (fixed air) formed. Cavendish says ... 

Cyanobacteria are key components of marine microbial communities contributing up to two-thirds of carbon dioxide fixed in oceanic systems. Although it is with C cycling that cyanobacteria are most notably associated, their contribution to the transformation of nitrogenous compounds is equally important, and indeed with roles in both regenerated and new N production and uttiisation, they are also inextricably linked to the global N-cycle. 

The first experimental evidence for the noble gases was obtained by Henry Cavendish in 1766. In a series of experiments on air, he was able to sequentially remove nitrogen (then known as phlogisticated air ), oxygen ( dephlogisticated air ), and carbon dioxide ( fixed air ) from air by chemical means, but a small residue, no more than one part in 120, resisted all attempts at reaction. The nature of Cavendish s unreactive fraction of air remained a mystery for more than a century. This fraction was, of course, eventually shown to be a mixture of argon and other noble gases. ... 

Fumaric acid is an intermediate of the TCA cycle. This oxidative pathway will generate one mole of fumarate per mole of glucose consumed. During active cell growth, however, this pathway cannot lead to a significant accumulation of fumarate. Fumarate generated in the TCA cycle is mainly utilized for the biosynthesis of cell constituents. Early experiments on the production of fumaric acid indicated the possible involvement of the reductive branch of the TCA cycle in fumaric acid accumulation. The carbon dioxide fixing reductive branch is... 

Research has been done on so-called natural biological sinks to determine the amount of carbon sequestration possible by this method. This work has indicated that natural biological sinks such as a pine forest do initially achieve elevated carbon dioxide fixing from the atmosphere but that this effect goes away after approximately 3 to 4 years. This effect, termed down regulation, can be the result of a long-term decrease of nitrogen or other needed nutrients in the forest over time. 

Fig. 6.3. Carbon dioxide-fixing pathway in the C4-plants (prepared mainly on the basis of Hatch et al., 1967). Circled numbers 1, phosphoenolpyruvate carboxylase 2, malate dehydrogenase (NADP ) 3, malate dehydrogenase (NADP ) (OAA decarboxylating) (= malic enzyme) 4, Rubisco 5, pyruvate orthophosphate dikinase. Pi, phosphate PPi, diphosphate...

Carbon Dioxide-Fixing Pathways Other than the Calvin-Benson Cycle in the Lithoautotrophs... 

In the landmark 1772 paper Priestley describes the isolation and properties of gases first observed by others but not so systematically. He described carbon dioxide ( fixed air —sometimes termed mephitic air), nitrogen (the air remaining after a candle had burned out in common air and following CO2 precipitation in lime water—he termed it phlogisticated air, often also termed by others mephitic air ), hydrogen (Cavendish s inflammable air —sometimes confused by Priestley with carbon monoxide), hydrogen chloride ( acid air —later marine air ), and nitric oxide (NO— nitrous air ). 

Six molecules of carbon dioxide fixed in the Calvin cycle do not end up in the same glucose molecule. However, labeling experiments show that six carbon atoms are incorporated into sugars for every six carbon dioxide molecules that enter the Calvin cycle. 

At the ecosystem scale, the flux of carbon among various reservoirs is a continuous process and follows a steady decay continuum. In a stepwise manner, carbon dioxide fixed during photosynthesis is returned to the atmosphere by the decomposition process, and the undecomposed organic matter is retained in the soil (Figure 5.7). The steps are as follows ... 

Cavendish obtained the first experimental evidence for the noble gases in 1766. In a series of experiments on air, he was able to sequentially remove nitrogen (then known as phlo-gisticated air ), oxygen ( dephlogisticated air ), and carbon dioxide ( fixed air ) from air... 

Priestley, Joseph (1733-1804) British chemist, who in 1755 became a Presbyterian minister. In Leeds, in 1767, he experimented with carbon dioxide ( fixed air ) from a nearby brewery with it he invented soda water. He moved to a ministry in Birmingham in 1780, and in 1791 his revolutionary views caused a mob to burn his house, as a result of which he emigrated to the USA in 1794. In the early 1770s he experimented with combustion and produced the gases hydrogen chloride, sulphur dioxide, and dinitrogen oxide (nitrous oxide). In 1774 he isolated oxygen see also Lavoisier, Antoine Laurent). 

The control of pH within the stroma of chloroplasts is clearly a significant factor in photosynthesis. The [CO2] available to ribulose bisphosphate carboxylase (Rubisco) kinetically determines its carbon dioxide fixing activity. In C3 plants, [CO2] is controlled in the equilibrium reaction catalysed by stromal carbonic anhydrase ... 

It is estimated that the net amount of carbon dioxide fixed... 

All of the carbon in PLA comes from carbon dioxide in the atmosphere. How All of the carbon in lactic acid comes from glucose, which is made by plants via photosynthesis. However, like all manufacturing processes, the produchon of PLA requires energy. The question is. Does the energy required to drive the processing cause more carbon dioxide emissions than the amount of carbon dioxide fixed in PLA This question can be addressed using a complete cradle-to-grave life-cycle inventory (LCI). 

Joseph Black, 1728-1799, was a Scottish chemist who discovered carbon dioxide ( fixed air ) by heating calcium carbonate. 

If a plant is illuminated in a closed container the carbon dioxide concentration inside the container eventually reaches a steady level which is known as the carbon dioxide compensation point. The final level represents the balance attained between carbon dioxide fixing and carbon dioxide releasing reactions. That carbon dioxide releasing reactions do occur is readily demonstrated if leaves which have previously been photosynthesising in labelled carbon dioxide are transferred to unlabelled carbon dioxide—labelled carbon dioxide can be detected in the atmosphere surrounding the leaves. This sort of experiment underlines the fact that when photosynthesis is measured as CO2 uptake or oxygen evolution the value obtained represents apparent photosynthesis—the balance between reactions resulting in... 

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