A summary of metabolism The unity of life At the cellular level of organization, the main chemical processes of all living matter are similar, if not identical. This is true for animalsplantsfungior bacteria ; where variations occur such as, for example, in the secretion of antibodies by some moldsthe variant processes are but variations on common themes.
Not only can organic material be taken up directly to provide carbon, nitrogen and phosphorus, it can be broken down by organisms Phosphate uptake process released as inorganic nutrients, such as orthophosphate, ammonia, nitrite and nitrate.
The metabolic breakdown scheme for typical organic materials in phytoplankton1 is shown below: Consequently, if five grams of flake food is added to a gallon aquarium, there is the potential for the inorganic orthophosphate level to be raised by 0. That fact can be a significant issue for reefkeepers: If the food is completely converted into tissue mass, then there will be no excess phosphate.
But much of the food that any heterotrophic organism consumes goes to provide energy, leaving a residue of CO2 carbon dioxidephosphate and a variety of nitrogen-containing compounds ammonia, nitrite, nitrate, etc.
A fish, whether it is an adult or a growing juvenile, consequently excretes much of the phosphorus that it takes in with its food as phosphate in its waste. Of course, overfeeding will result in more phosphate delivery than will reduced feeding levels.
Unfortunately, many types of seafood available at the grocery store have various inorganic phosphate salts intentionally added to them as preservatives. These foods include canned and frozen seafood, as evidenced by their label, and even some fresh seafood.
In these cases, rinsing the food before using it may help to reduce the phosphate load it adds to the aquarium. Finally, tap water can also be a significant source of phosphate. The tap water that the Massachusetts Water Resources Authority supplies to me is acceptably low in phosphate, or at least it was the last time I measured it.
In other water supplies, however, phosphate levels can be too high for reefkeeping. In New York City officials reported that water samples showed phosphate levels as high as 3 ppm.
I'd recommend phosphate testing to anyone with an algae problem who uses tap water, in order to ascertain whether phosphate in the water is an issue. On the other side of this issue are those reef aquaria without fish. Because phosphorus is required for growing tissue, it is mandatory that some phosphorus source be available to corals and invertebrates growing in a reef aquarium.
Finding a source is trivial if fish are in the aquarium, but in aquaria without fish, reefkeepers must somehow add phosphorus.
The solution to this problem is easy: Calcification Inhibition by Phosphate One important issue relating to elevated phosphate in reef aquaria has to do with the inhibition of calcification by phosphate and phosphate-containing organics.
Phosphate is known to inhibit the precipitation of calcium carbonate from seawater. Exactly how the phosphate gets into the ECF isn't well understood. The chemical structure of the organophosphate "etidronate," shown in a fully protonated form.
This inhibition of calcification takes place at concentrations frequently attained in reef aquaria, and may begin at levels below those detectable by hobby test kits.
For example, one research group found that long-term enrichment of phosphate 0. Certainly, some phosphorus goes into the bodies of growing organisms, including bacteria, algae, corals and fish. Some of these organisms stay permanently in the aquarium, and others may be removed by algae harvesting, skimming of small organisms and even pruning of corals.
These and other mechanisms are discussed in subsequent sections of this article.
Phosphate Reduction via Calcium Phosphate Precipitation One mechanism for phosphate reduction in reef aquaria may simply be the precipitation of calcium phosphate, Ca3 PO4 2. The water in many reef aquaria is supersaturated with respect to this material, as its equilibrium saturation concentration in normal seawater is only 0.
As with CaCO3, the precipitation of Ca3 PO4 2 in seawater may be limited more by kinetic factors than by equilibrium factors, so it is impossible to say how much will precipitate under reef aquarium conditions without, of course, somehow determining it experimentally.
This precipitation may be especially likely where calcium and high pH additives such as limewater enter the aquarium water. Combined with the locally high calcium level also from the limewaterthe locally high PO level may push the supersaturation of Ca3 PO4 2 to unstable levels, causing precipitation.
If these calcium phosphate crystals are formed in the water column e. Many reefkeepers accept the concept that adding limewater reduces phosphate levels. This may be true, but the mechanism remains to be demonstrated. Craig Bingman has done a variety of experiments related to this hypothesis, and has published them in the old Aquarium Frontiers magazine.
While many aquarists may not care what the mechanism is, knowing how it occurs will help us understand the limits of this method, and how to best employ it. One possible mechanism could be through calcium phosphate precipitation, as outlined above.
A second mechanism for potential phosphate reduction when using high pH additives is the binding of phosphate to calcium carbonate surfaces.
The absorption of phosphate from seawater onto aragonite is pH dependent, with the binding maximized at around pH 8. Habib Sekha owner of Salifert has pointed out that limewater additions may lead to substantial precipitation of calcium carbonate in reef aquaria.
This idea makes perfect sense. After all, it is certainly not the case that large numbers of reef aquaria exactly balance calcification needs by replacing all evaporated water with saturated limewater.Phosphate rock is the main source of phosphorous which is essential to all forms of life. It is a key component of DNA, it is used in the control of energy transfer and storage at the cellular level as well as playing an important role in metabolic processes.
PHAST(PHAge Search Tool) is a web server designed to rapidly and accurately identify, annotate and graphically display prophage sequences within bacterial genomes or r-bridal.com accepts either raw DNA sequence data or partially annotated GenBank formatted data and rapidly performs a number of database comparisons as well as phage “cornerstone” feature identification steps to locate.
Dec 09, · Nutrient uptake is a central property of ocean biogeochemistry, but our understanding of this process is based on laboratory cultures or bulk environmental studies. Thus, mathematical descriptions of nutrient uptake, at the heart of most biogeochemical models, must rely on this limited information.
⇑ Back to the top ⇑ Catalytic mechanism of phosphopentose epimerase. Also this reaction, like those catalyzed by 6-phosphogluconate dehydrogenase and ribose 5-phosphate isomerase, proceeds through the formation of an enediol intermediate, but with the double bond between C-2 and C-3 and not between C-1 and C During the reaction an amino acid residue present in the active site of the.
The glycolysis page describes the process and regulation of glucose breakdown for energy production as well as the disruption in theses processes due to alcohol consumption. Only a small proportion of total body iron daily enters or leaves the body's stores on a daily basis (Figure1).
Consequently, intercellular iron transport, as a part of the iron reutilization process, is quantitatively more important that intestinal absorption.