Nearly 99% of the mass of your human body consists of just 6 chemical elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Another 5 elements make up most of the last percentage point: potassium, sulfur, sodium, chlorine, and magnesium
Oxygen of course, because carbon is just the product of respiration, and we don't acutally breathe hydrogen or nitrogen - we might inhale them, of course, but we don't use them. They're just expelled.
Oxygen is used in many processes in our bodies both in big ones such as respiration or molecular ones like many cellular processes.
Rna mrna trna <span>known as ribosomes; and finally, tRNA, or transfer </span>RNA<span>, that ferry amino acids to the ribosome to be assembled </span>
the RBC first is in the arteries then it reaches the body cells via the capillaries then the deoxygenated rbc reaches the heart through veins which carry those