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.
It is always paired with adenine by two hydrogen bonds. Thymine is a pyrimidine that is found only in DNA molecules and is synthesized from uracil. Uracil is a pyrimidine type nitrogenous base that is found only in RNA molecules. It always pairs with adenine. Chemical difference of uracil and thymine is very small. Uracil has a hydrogen atom at C-5 carbon while thymine has a methyl group at the same carbon.