In this way a DNA molecule is similar in structure to a ladder in which the sugar and phosphate groups make the uprights and the nitrogen base groups the rungs. There are four types of nitrogen bases or base groups. 1  Adenine (A). 2  Thyamine (T).3  Cytosine (C). 4  Guanine (G).he nucleotides in the DNA molecule are linked in series from one phosphate, to the next sugar, to the next phosphate and so on. The DNA molecule can be considered as a ladder with the phosphate and the sugar molecules making up the uprights and the bases making up the rungs.
Charleston Airport Shuttles. CHS airport has limousines and taxi services at low rates for incoming travelers. Charleston International Airport is South Carolinaâs busiest airport and is the oldest city of Charleston which rich in history and hospitality.
Charleston, South Carolina 29401. The Cruise Ship Passenger Terminal is located in downtown Charleston in the heart of the historic district. It is easily reached via several major routes into the City. The major routes into Charleston are via Interstate 26, Highway 17-South, Highway 17-North and I-526.