Chemical Composition of the Human Body

As indicated in chapter 3.6., the time required for the cremation process depends mainly on the structure and chemical composition of the human body, but to a significant extent also on the construction and operation of the cremation oven. 

The bowel, one of the largest and most metabolically active organs, contains bacteria that may change the chemical composition of the human body. In renal failure the altered bacterial flora cause the accumulation of aliphatic amines in the gut (09, S25). Bacteria transform part of the choline in the gut to trimethylamine, which is reabsorbed and then either oxidized or demethylated to dimethylamine in the liver (S24). Dimethylamine enters the circulation and is excreted in the bile and urine. The trimethylamine and dimethylamine in the exhaled air of uremic patients may contribute to the classic fishy breath, which can be improved by hemodialysis or by gut sterilization with nonabsorbable antibiotics (S23, S25). The overall role of these compounds as uremic toxins, however, remains to be defined. 

The carbon-autotrophic green plant is the primary producer of carbohydrates on the earth and uses carbohydrates extensively as storage and cell-wall substances (starch, cellulose, etc). The nitrogen-hetero-trophic animal usually consumes a rather protein-rich diet and uses proteins as supportive materials The approximate chemical composition of the human body is shown in Table 2. Most of the mass of bacteria (see Escherichia coli) is made up by proteins, which may account for 70 % of the dry weight. Numerically,... 

Table 2. Chemical composition of the human body (adapted from Rapoport). The values are rounded off. ...

Typical pH Values of Biological Materials and Foods Chemical Composition of the Human Body... 

Kieffer (1991) cites 37 chemical species as usually present in the elemental composition of the human body. Among them there are elements abundant in nature, such as calcium, sodium and potassium, as well as rather rare ones, such as iodine and cobalt. 

Microspheres made of various polymers biodegradable to nonharm-ful compounds that could be metabolized and/or removed from organisms found many applications in medicine as carriers of drugs or other bioactive compounds [1 ]. Besides chemical composition there are also other properties of microspheres that are of primary importance to their medical applications. In particular, average diameters and diameter distributions illustrated in Table 1 based on data published in [5] are the relationship between the diameters of microspheres and their localization in various cells and tissues of the human body. 

Understanding the total nutritional needs of the human body requires a more detailed consideration of the chemical composition of different nutrients. As we have seen in Chapter 22, the body cannot synthesize many of the amino acids needed to build proteins. For this reason, the body requires proteins that contain the essential amino acids in sufficient quantities. Too little animal protein will lead to nutritional deficiencies because plant proteins do not contain an adequate supply of all the amino acids that active humans must receive from their diets. 

Biochemistry is the study of the chemical composition and structure of the human body and other living organisms, of the chemical reactions that take place within these organisms, and of the drugs and other substances that interact with them. 

The fact that foods are chemical systems is an important fundamental principle of food science. The same basic elements that form the cells and tissues of the human body are the ones that make up the majority of the foods people eat. These include carbon, oxygen, hydrogen, nitrogen, sulfur, and calcium. The chemical composition of foods and the... 

Table 3.1 Approximate values for the chemical composition of the adult human body...

---