Nucleotide vs Base
In here, base means the nitrogenous base in a nucleotide. It has basic characteristics due to the lone pairs of nitrogen. Here, base doesn’t imply the usual bases we come across in chemistry, but these are special molecules present in biological systems with basic properties.
Nucleotide is the building block of two crucial macromolecules (nucleic acids) in living organisms called DNA and RNA. They are the genetic material of an organism and are responsible for passing genetic characteristics from generation to generation. Further, they are important to control and maintain cellular functions. Other than these two macromolecules, there are other important nucleotides. For example, ATP (Adenosine tri phosphate) and GTP are important for energy storage. NADP and FAD are nucleotides, which act as cofactors. Nucleotides like CAM (cyclic adenosine monophosphate) are essential for ATP cell signaling pathways.
A nucleotide is composed of three units. There is a pentose sugar molecule, a nitrogenous base, and the phosphate group/s. According to the type of pentose sugar molecule, nitrogenous base, and the number of phosphate groups, nucleotides differ. For example, in DNA, there is a deoxyribose sugar and in RNA, there is a ribose sugar. The phosphates are linked to the –OH group of carbon 5 of the sugar. In the nucleotides of DNA and RNA, normally there is a one phosphate group. However, in ATP, there are three phosphate groups. The linkages between phosphate groups are high energy bonds. Primarily, there are eight types of nucleotides in DNA and RNA.
• Deoxy adenosine mono phosphate
• Deoxy guanosine mono phosphate
• Deoxy cytidine mono phosphate
• Deoxy thymidine mono phosphate
• Adenosine mono phosphate
• Guanosine mono phosphate
• Cytidine mono phosphate
• Uridine mono phosphate
Above eight nucleotides are the basic types. And other nucleotides can be derivatives of these. Nucleotides can be linked to each other to form a polymer. This linkage occurs between the phosphate group of a nucleotide with a hydroxyl group of the sugar. By making this kind of phosphodiester bonds, macromolecules like DNA and RNA are formed.
Base group is part of a nucleotide. There are mainly two groups of nitrogenous bases as pyridines and pyrimidines. Pyrimidines are smaller heterocyclic, aromatic, six-member rings containing nitrogens at 1 and 3 positions. Cytosine, thymine, and uracil are examples for pyrimidine bases. Purine bases are much larger than pyrimidines. Other than the heterocyclic aromatic ring, they have an imidazole ring fused to that. Adenine and guanine are the two purine bases. In DNA and RNA, complimentary bases form hydrogen bonds between them. That is adenine: thiamine/ uracil and guanine: cytocine are complimentary to each other. Base is the most important component in the nucleotide. Thus, in DNA, the structure is coiled in a way to protect the middle base groups. The base sequence determines the genetic sequence, and they are responsible for all the cell controlling activities. Further, it is important to store the genetic characteristics and pass them from generation to generation.
What is the difference between Nucleotide and Base?
• Nitrogenous base is a part of a nucleotide.
• Base is a heterocyclic ring containing nitrogen. Other than this in a nucleotide, there is a pentose sugar and a phosphate group too.
• Base is the most important and functional unit of nucleotides in DNA or RNA.
• The hydrogen bonding between bases keeps the double helix structure of DNA.