The tangent plane at the point x=a, y=b is the plane that contains all the tangent vectors (at the point) of curves on the surface that pass through the point (a,b,f(a,b)). Another way to define it is to say that this is the plane through the point (a,b,f(a,b)) which is perpendicular to the NORMAL to the surface at that point. The NORMAL to the surface at a point is just defined as the direction perpendicular to all tangent vectors to the surface at that point. Therefore all we need to do to find the equation of the tangent plane is to find a normal to the surface at that point.
Apart from adenine (A), cytosine (C), guanine (G), thymine (T) and uracil (U), DNA and RNA also contain bases that have been modified after the nucleic acid chain has been formed. In DNA, the most common modified base is 5-methylcytosine (m 5 C). In RNA, there are many modified bases, including those contained in the nucleosides pseudouridine (Ï), dihydrouridine (D), inosine (I), and 7-methylguanosine (m 7 G).
In RNA the four bases are the same except for thymine which is replaced by uracil (U), a pyrimidine base. Uracil-click on image to open. Adenine, guanine, thymine, cytosine and uracil are bases because of the presence of one or more of the following groups: - NH 2, - NH-and = N-groups.ucleic acids Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are made up of nucleic acids found in the nuclei of living cells. They are the vehicles of genetic inheritance. Nucleic acids are condensation polymers of nucleotides.