Nucleotide Phosphate ester biologically important

Monosaccharides also form phosphate esters with phosphoric acid. Monosaccharide phosphate esters are important molecules in biological system. For example, in the DNA and RNA nucleotides, phosphate esters of 2-deoxyribose and ribose are present, respectively. Adenosine triphosphate (ATP), the triphosphate ester at C-5 of ribose in adenosine, is found extensively in living systems. 

T.l.c.— The separation of phosphonic acid derivatives has been studied. Reports on the application of t.l.c. to the analysis and separation of nucleotides and other biologically important phosphates abound. Enzymatic reagents have been used to develop chromatograms of phosphate esters which inhibit cholinesterase. Clean, sharp-edged spots against a dark background are obtained. ... 

The chemistry of phosphate esters is rich and varied. Phosphate esters are important in biological systems. The phosphate ester of a nucleoside (a nucle-obase attached to a ribose derivative see Chapter 28, Section 28.5) is called a nucleotide. These are structural components used in DNA and RNA. Using adenosine (210) as an example, there are three possible monophosphate esters 211, 212, and 212. The pyrophosphate (diphosphate) derivative is adenosine 5 -diphosphate (214). The symbol A is used to designate an adenosine derivative in biology, so 211 is abbreviated 5 -AMP (adenosine 5 -monophosphate) and 214 is 5 -ADP (adenosine 5 -diphosphate). The numbering is explained in Chapter 28, Section 28.5. 

We have seen the formation of sulfonate esters from sulfinic acids. Sulfuric acid (A) can form esters as well—either the monoesters (B) or the diester (C), which is known as a dialkyl sulfate. Esters of phosphoric acid (D) play a prominent role in biology. The phosphate linkages in nucleotides (see Chapter 28, Section 28.5) are important. Using D as a template, draw the mono- and diesters of phosphoric acid using cyclopentanol as the alcohol component. Take each of the phosphate esters you have drawn and draw the product you will obtain when they are treated with a base such as sodium hydride (NaH). 

The addition of one, two or three phosphate groups to the sugar of a nucleoside by ester linkage (alcoholic-OH + acid- ester) derives a nucleotide. The nomenclature of the nucleotide is based upon the name of the nucleoside plus the position and number of the phosphate groups, e.g. adenosine 3 -monophosphate, guanosine 5 -triphosphate. Although phosphorylation may occur at the 2, 3 or 5 positions of a ribonucleoside and at the 3 or 5 positions of a deoxyribonucleoside, the 5 -nuc-leotides are of major biological importance. 

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