Enzymes chemical elements

Not surprisingly, only about 20 of the chemical elements found on Earth are used by living organisms (Chapters 3 and 8). Most of them are common elements. Rare elements are used, if at all, only at extremely low concentrations for specialized functions. An example of the latter is the use of molybdenum as an essential component of nitrogenase, the enzyme that catalyzes the fixation of elemental dinitrogen. Because they are composed of common elements, living organisms exert their most profound effects on the cycles of those elements. 

The studies of the composition and state of chemical elements on enzyme-modified wool surfaces (carbon, nitrogen, oxygen, sulphur) as compared to untreated ones were performed by means of XPS analysis (Vacuum System Workshop Ltd., England) using non-monochromatized AlKa radiation with energy 1486.6 eV, 10 kV and 200 W. The base pressure in the analysis chamber was 3 x 10-6 Pa [30], XPS spectra were acquired in the constant analyser transmission mode with energy of electron transmission 22 eV. 

We fool ourselves, however, if we dwell on energy alone. The uses of all natural resources are intertwined. Oil is of little use without engines built of iron, copper, zinc, and other metals. Farmlands will yield maximum crops only if they are tilled by tractors emd plows and fertilized with compounds of phosphorus, nitrogen, and potassium. A failure in the supply of one resource will inevitably influence the use of others. Viewing the panoply of natural resources, we see that one group, metals, occupies a unique position. Without metals we could not build machines to replace human muscle. Without metals we could use little of the available energy. Metals are, in effect, the enzymes of industry. If supplies of metals are limited, then society must ultimately be limited too. It is my contention that the distribution of the chemical elements in nature means, inevitably, that there are natural limits to supplies of metals, and that these limits are much more important to the future of society than limits on energy. I also contend that, with sufficient work, the limits can be predicted. It is the piu-pose of this paper, therefore, to explore briefly the way metals occur and to attempt to place in perspective the limitations they may ultimately impose on us. 

In the next chapter, we will introduce and discuss some of the enzymes, hormones, and proteins that use metals and other chemical elements to keep our bodies safe, strong, and productive. 

Enzymes, hormones, and what I call special proteins are very important in how they influence our body chemistry, which is why I ve devoted a chapter to them. The reason they are so significant is that dietary deficiencies of any chemical elements needed by them usually have a drastic impact on health, tending to do more harm to our bodies in a shorter period of time than deficiency effects on any other body parts. All three are made of the chemical elements I ve discussed in previous... 

A sensor array for monitoring indicators of mannnalian cell metabolic status has been reported by Pemberton et al. [33], and is based on both enzyme-modified elements and chemical sensors for temperature, pH, and dissolved oxygen. The array, fabricated in a silicon platform using MEMS technology, consists of five-well sensor strips with a multipotentiostat to switch between potentiometric and amperometric measurement modes. Screen-printed biosensors for glucose and lactate were grafted onto two of the weUs. The authors envision applications to cell culture and cytotoxicity studies. 

Tea leaf, in common with all plant leaf matter, contains the full complement of genetic material, enzymes, biochemical intermediates, carbohydrates, protein, lipids, and structural elements normally associated with plant growth and photosynthesis. In addition, tea leaf is distinguished by its remarkable content of methylxathines and polyphenols. These two groups of compounds are predominantly responsible for those unique properties of tea that account for its popularity as a beverage. It must be noted that the chemical composition of tea leaf varies with climatic condi-... 

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