Phosphoric acid contains three monovalent hydroxyl groups and a divalent oxygen atom, all connected to the pentavalent phosphorus atom. The molecular structure and formula for phosphoric acid (H3PO4) is shown here.
There are two kinds of nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is found mainly in the chromatin of the cell nucleus, whereas most of the RNA (90%) is present in the cytoplasm and a little (10%) in the nucleolus. Upon hydrolysis, the two nucleic acids yield three components of phosphoric acid, a…
DNA is considered to be the main source of genetic information. It is exclusively responsible for the identity of different species of organisms. DNA controls all the cellular functions. The DNA is organised into genes, the fundamental units of genetic information. The genes control the protein synthesis through the mediation of RNA as shown below:…
‘The nucleic acids are biopolymers of high molecular weight with mononucleotide as their repeating units.’ The elemental compositions of nucleic acids are carbon, hydrogen, oxygen, nitrogen, and, strangely enough, phosphorus.
The pneumococcus bacterium played an important part in the discovery of the genetic role of DNA. A slimy, glistening polysaccharide capsule normally surrounds a pneumococcus. This outer layer is essential for the pathogenicity of the bacterium, which causes pneumonia in humans and other susceptible mammals. Mutants devoid of a polysaccharide coat are not pathogenic. The…
DNA is composed of deoxyribonucleotides. Each deoxyribonucleotide contains a base, a sugar, and a phosphate group. The base in the DNA macromolecule carries genetic information, whereas the sugar and phosphate group support the structural role. The following experiments prove that DNA is a genetic material:
Leukotrienes are synthesised by leucocytes, mast cells, lung, heart, spleen, and so on. Leukotriene causes contraction of smooth muscles, broncho constriction, vasoconstriction, adhesion of white blood cells, and release of lysosomal enzymes.
PGI2 inhibits platelet aggregation. Thromboxanes TX A2 and PG E2 promote platelet aggregation and blood clotting that might lead to thrombosis. Thus, PG I2 acts as vasodilator, while TX A2 is a vasoconstrictor.
PGE decreases lipolysis, increases glycogen formation, and promotes calcium mobilisation from the bone.
PGE increases glomerular filtration rate (GFR) and promotes urine output. Excretion of Na+ and K+ is also increased by PGE.