From the sandy creek in the Cajon Pass, into Lone Pine Canyon, up and along the Blue Ridge to the summit of Mt. Baden-Powell, then edging along to Islip Saddle, the trail within proximatey to Wrightwood provides views of the extended metropolitan areas of Southern California and the Mojave Desert.
Guanine, along with adenine and cytosine, is present in both DNA and RNA, whereas thymine is usually seen only in DNA, and uracil only in RNA. Guanine has two tautomeric forms, the major keto form (see figures) and rare enol form. It binds to cytosine through three hydrogen bonds.
Cytosine is an important part of DNA and RNA, where it is one of the nitrogenous bases coding the genetic information these molecules carry. Cytosine can even be modified into different bases to carry epigenetic information. Cytosine has other roles in the cell, too, as the energy carrier and cofactor CTP. Structure. As a nitrogenous base, cytosine is full of nitrogen atoms (it has three). It also has one ring of carbon, which makes it a pyrimidine.