Profesor

Most of the human body is made up of water, H2O, with cells consisting of 65-90% water by weight. Therefore, it isn't surprising that most of a human body's mass is oxygen. Carbon, the basic unit for organic molecules, comes in second. 99% of the mass of the human body is made up of just six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus.
1. Oxygen (65%) function: na sheep preparation the blood flow to fetal organs was studied 3 to 10 days after surgery by means of the microsphere technique over a range of fetal arterial O2 content from 6 to 1 mM. Blood flows to neural tissues (cerebrum, cerebellum, brain stem), heart, and the adrenals increased in inverse relation to arterial O2 content.
2. Carbon (18%) function: The work functions of multi- andsingle-walled carbon nanotubes are found to be 4.95 and 5.05 eV, respectively. 
3. Hydrogen (10%) function: We study the diffusion of helium and other heavy elements in the solar interior by solving exactly the set of flow equations developed by Burgers for a multi-component fluid, including the residual heat-flow terms. No approximation is made concerning the relative concentrations and no restriction isplaced on the number of elements considered. We give improved diffusion velocities for hydrogen, helium, oxygen and iron, in the analytic form derived previously by Bahcall and Loeb. These expressions for the diffusion velocities are simple to program in stellar evolution codes and are expected to be accurate to $\sim 15\%$. Our complete treatment of element diffusion can be directly incorporated ina standard stellar evolution code by means of an exportable subroutine, but, for convenience, we also give simple analytical fits to our numerical results.
4. Nitrogen (3%) function: Nitrogen is the most commonly used mineral nutrient. It is important for protein production. It plays a pivotal role in many critical functions (such as photosynthesis) in the plant and is a major component ofamino acids, the critical element constituent component of proteins. These amino acids are then used in forming protoplasm, the site of cell division and plant growth. Nitrogen is necessary for enzymatic reactions in plants since all plant enzymes are proteins. It is a necessary component of several vitamins, e.g., biotin, thiamine, niacin and riboflavin. N is part of the nucleic acids (DNA and RNA).5. Calcium (1.5%) function: Calcium is tightly linked to many of the roles that vitamin D plays in the body. In bone health (and other physiologic systems), calcium is a key player. Calcium is a mineral that must be constantly eaten to build bone and maintain the blood level of calcium.
6. Phosphorus (1.0%) function: The bone turn-over was increased in the hyperthyroid patients with anincrease both in bone resorption and bone formation. Serum alkaline phosphatase was increased and positively correlated to the amount of osteoid and to the extent of tetracycline-labelled surfaces. The osteoclastic resorption was positively and the bone formation inversely correlated to thyroid activity. This might explain the reduced amount of trabecular bone found in hyperthyroidism. The moststriking feature was, however, a pronounced increase in osteoclastic activity in cortical bone followed by increased porosity. The osteoclastic resorption in cortical bone was positively correlated to serum concentrations and urinary excretions of calcium and phosphorus. 
7. Potassium (0.35%) function:  Potassium is essential for maintaining proper fluid balance, nerve impulse function, musclefunction, cardiac (heart muscle) function.
8. Sulfur (0.25%) function: Iron–sulfur (Fe–S) clusters are ubiquitous prosthetic groups required to sustain fundamental life processes. The assembly of Fe–S clusters and insertion into polypeptides in vivo has recently become an area of intense research.
9. Sodium (0.15%) function: The body needs a small amount of sodium to help maintain normal blood...