Types Of Nucleic Acid PDF

TYPES OF NUCLEIC ACID  WHAT IS NUCLEIC ACID? are large biomolecules that play essential roles in all cells and viruses. DNA-Deoxyribonucleic acid is the molecule that carries genetic information for the development and functioning of an organisms. RNA- Ribonucleic acid is a nucleic acid pres...

TYPES OF NUCLEIC ACID  WHAT IS NUCLEIC ACID? are large biomolecules that play essential roles in all cells and viruses. DNA-Deoxyribonucleic acid is the molecule that carries genetic information for the development and functioning of an organisms. RNA- Ribonucleic acid is a nucleic acid present in all living cells that has structural similarities to DNA. Unlike DNA, however, RNA is most often single-stranded. NUCLEOTIDES: STRUCTURAL BUILDING BLOCKS FOR NUCLEIC ACIDS  A nucleic acid is an unbranched polymer containing monomer units called nucleotides.  A nucleotide consists of a sugar molecule (either ribose in RNA or deoxyribose in DNA) attached to a phosphate group and a nitrogen-containing base. NUCLEOTIDE STRUCTURE Pentose Sugars PENTOSE SUGARS The sugar unit of a nucleotide is either the pentose ribose or the pentose 2’-deoxyribose. NITROGEN CONTAINING HETEROCYCLIC BASE Five nitrogen-containing heterocyclic bases are nucleotide components. Three of them are derivatives of pyrimidine, a monocyclic base with base with fused five and six-membered rings.  Purines and Pyrimidines are nitrogenous bases that make up the two different kinds of nucleotide bases in DNA and RNA. The two-carbon nitrogen ring bases (adenine and guanine) are purines, while the one-carbon nitrogen ring bases (thymine and cytosine) are pyrimidines.  CUT the Pie": CUT: Cytosine, Uracil, Thymine; Pie (Pyrimindines) "Pure As Gold (Pur AG)": Purines are Adenine, Guanine The chemical structure of all purines (adenine, guanine) and pyrimidines (cytosine, thymine, uracil) PHOSPHATE The third component of nucleotide derived from phosphoric acid (H3PO4). Under cellular pH conditions, the phosphoric acid loses two of its hydrogen atoms to give a hydrogen phosphate ion (HPO4). III. NUCLEOTIDE FORMATION The formation of a nucleotide from a sugar, a base, and a phosphate can be visualized as a two-step process. 1. The pentose sugar and nitrogen-containing base react to form subunit entity called a nucleoside.  2. The nucleoside reacts with a phosphate group to form the three-subunit entity called a nucleotide. It is nucleotides that become the building blocks for nucleic acids.  Nucleotide formation THREE COMPONENTS Pentose Sugar ( Ribose/deoxyribose) Nitrogenous base (Purine/Pyrimidine) Phosphate group (s) NUCLEOSIDE FORMATION TWO COMPONENTS Pentose Sugar ( Ribose/Deoxyribose Nitrogenous base (Purine/Pyrimidine) Eight Combination of Nucleoside RNA Nucleosides DNA Nucleoside Ribose-adenine deoxyribose-adinine Ribose-cytosine deoxyribose-cytosine Ribose-guanine deoxyribose-guanine Ribose-uracil deoxyribose-uracil NUCLEOSIDES ARE NAMED AS DERIVATIVES OF THE BASE THAT THEY CONTAIN; THE BASE’S NAME IS MODIFIES USING A SUFFIX. 1. For pyrimidine bases, the suffix -idine is used (cytidine, thymidine, uridine). 2. For purine bases, the suffix -oxine is used (adenosine, guanosine) 3. The prefix deoxy- is used to indicate that the sugar present is deoxyribose. No prefix is used when the sugar present is ribose. IMPORTANT CHARACTERISTICS OF NUCLEOTIDE FORMATION PROCESS OF ADDING A PHOSPHATE GROUP TO A NUCLEOSIDE ARE THE FOLLOWING: 1. The phosphate group is attached to the sugar at the c’5 position through a phosphodiester linkage. 2. As with nucleoside formation, a molecule of water is produced in nucleotide formation. Thus, overall, two molecules of water are produced in combining a sugar, base, and phosphate into a nucleotide.