Carbohydrates assimilation

Regarding the total amount of assimilated biomass, carbohydrates/polysaccha-rides represent the dominant class with an estimated amount of 1-4 X 10" tons of dry matter produced by photosynthesis annually ... 

As described in U.S, Patent 3,086,912, the process comprises cultivating Streptomyces lincolnensis var. lincolnensis in an aqueous nutrient medium containing a source of assimilable carbohydrate and assimilable nitrogen under aerobic conditions until substantial activity is imparted to the medium by production of lincolnensin and isolating the lincol-nensin so produced. 

The outcome of the photosynthesis processes is ultimately similar in all green plants carbon dioxide from the atmosphere is taken up by the plants, where it reacts with water to form carbohydrates and oxygen the carbohydrates are assimilated by the plants while the oxygen is released to the atmosphere (see Textbox 53). Extensive studies have shown that the conversion of carbon dioxide and water into carbohydrates in different plants may follow, however, one of three different photosynthetic pathways, which are usually referred to as the C3, C4, and CAM paths. Each type of plant follows just one of these three pathways. 

Since in mammalian species metals first need to be assimilated from dietary sources in the intestinal tract and subsequently transported to the cells of the different organs of the body through the bloodstream, we will restrict ourselves in this section to the transport of metal ions across the enterocytes of the upper part of the small intestine (essentially the duodenum), where essentially all of the uptake of dietary constituents, whether they be metal ions, carbohydrates, fats, amino acids, vitamins, etc., takes place. We will then briefly review the mechanisms by which metal ions are transported across the plasma membrane of mammalian cells and enter the cytoplasm, as we did for bacteria, fungi and plants. The specific molecules involved in extracellular metal ion transport in the circulation will be dealt with in Chapter 8. 

Aqueous suspensions of 6-methyluracil, when administered orally to rats, accelerate and intensify the assimilation of alimentary carbohydrates and increase hepatic glycogen synthesis [267]. 

The photoreductive synthetic process that promotes the assimilation of carbon dioxide into carbohydrates, other reduced metabolites, as well as ATP (synthesis of the latter is termed photophosphorylation). Photosynthesis is the primary mechanism for transducing solar energy into biomass, and green plants utilize chlorophyll a to capture a broad spectrum of solar radiant energy reaching the Earth s surface. Photosynthetic bacteria typically produce NADPH, the reductive energy of which is converted to ATP. 

Potatoes have been valued around the world for centuries because they are an easily cultivated, easily prepared and readily assimilated source of carbohydrate energy. The ease with which potatoes are digested has, however, become a double-edged sword, as the interrelated epidemics of metabolic syndrome and type 2 diabetes become global crises linked to rising obesity. At the same time as carbohydrates have been blamed for obesity, glucose intolerance has become recognized as a core feature of the metabolic syndrome and type 2 diabetes (Seidell, 2000). 

Stage 3 Regeneration of Ribulose 1,5-Bisphosphate from Triose Phosphates The first reaction in the assimilation of C02 into triose phosphates consumes ribulose 1,5-bisphosphate and, for continuous flow of C02 into carbohydrate, ribulose 1,5-bisphosphate must be constantly regenerated. This is accomplished in a series of reactions (Fig. 20-10) that, together with stages 1 and 2, constitute the cyclic pathway shown in Figure 20-4. The product of... 

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