When the total pressure is considered, as in chemical analysis and in thermodynamics it is often referred to as psia or absolute pressure of the substance or of the fluid which would then include the atmospheric pressure. It is important to include the subscript g or a to define which pressure is being noted. Psi can also be the difference between two pressures, be they gage or absolute. Psi is also used in materials engineering referring to the unit stress caused when a load is imposed on a structure or on a part.
Adenine is one of the two purine nucleobases (the other being guanine) used in forming nucleotides of the nucleic acids. In DNA, adenine binds to thymine via two hydrogen bonds to assist in stabilizing the nucleic acid structures. In RNA, which is used for protein synthesis, adenine binds to uracil.
DNA contains four bases:Guanine, Cytosine, Adenine, and Thymine. The complementary base pairs of guanine with cytosine and adenine with thymine connect to one another using hydrogen bonds. These hydrogen bonds between complementary nucleotides is what keeps the two strands of a DNA helix together.his partial positive charge is attracted to the partial negative charge of the hydrogen bond acceptor (an electron density rich atom). The chemical bond formed between the hydrogen-bond donor, hydrogen atom, and hydrogen-bond acceptor has a straight, linear structure.