 In this module, we will discuss the isomerism with respect to alpha and beta configuration, which is the formation of a ring structure from a straight chain structure of a monosaccharide. In aqueous solution, aldotetrosis, aldotetrosis kya hai, tetra jis me char carbon hai, aldehyde group attach hai, and all monosaccharides with five or more carbon atoms in the backbone occur predominantly as cyclic or ring structure. In the ring structure, the carbonyl group has formed a covalent bond with the oxygen of a hydroxyl group of a long chain of the carbon. Therefore, forming an ether linkage, ether linkage kya hai jis me ek oxygen hai aur dono side pe r groups attached hai. So, ek carbon atom number, first or carbon atom number five ke dirmyaan ek cyclic ring banshata hai, which is shown in this slide. So, this is the carbon atom number one having the carbonyl group. Aur carbon atom number five ke dirmyaan, in dono ke dirmyaan, ye five hai, ye nazar aar hai. In dono ke dirmyaan ek ring form banshata hai, jo ek hi linear structure ko convert kar deta hai, in the structure of a ring. Is ring banshata hai, and other asymmetric carbon atom is formed. So, forming an other type of isomerism, which is called alpha and beta isomers. As the two reacting groups, the aldehyde and the alkoholic group belong to the same molecule. Therefore, a cyclic structure is formed. Eki molecule ke dono part hai. Isliye straight chain convert hojai gi ring structure mein, jo usi ka part hoega. The formation of these ring structures is the result of a general reaction between alcohols and aldehydes or ketones. Jab aldehyde ke saath alkohol react kerega to wo hemi acetyl binayega. Jab keto group ke saath alkohol react kerega to wo hemi ketol binayega. Ye hemi acetyl aur hemi kya? Hemi means half. Is ka matlab hai ke half ye apas mein inter convertible hai. Alkohol group aur aldehyde group in case of hemi acetyl and alkoho group and keto group in case of hemi ketols. Ye apas mein inter convertible hai. Agar ek alkohol group attach hoata hai, uske saath, aldehyde ke group ke saath, to it will form aldehyde aur hemi acetyl and hemi ketols. Which contains and is se kya? We have already defined kya hoega? An additional or additional asymmetric carbon atom. Thus it will form an other type of isomerism of having an alpha beta to isomeric forms. This is the general reaction of formation of aldehyde and alcohol. If this aldehyde reacts with a molecule of alcohol, this hemi acetyl is formed, which is having this alkohol group and this acetyl group. So these two groups are inter convertible to in each other. Iske waira se hemi acetyl aur hemi ketols, if ketone group is present here, it's reaction will be with alcohol, it will form a hemi ketols. We have already said that this is inter convertible. Half is in the form of alcoholic forms and half is in the keto form. keto form. When an other alcoholic group is attached to this amyacetol and amyketol in this reaction, it is converted in a complete acetol and in case of ketone, it is converted in a ketol group. We discussed this earlier. When glycosic linkage is formed, this amyketol and amyacetol are converted in a complete amyketol and in acetol groups where the interconversion ends. The glycosic linkage we have discussed in the previous modules that that particular linkage is formed between two different monosecrite units. Whereas this amyacetol and amyketol are formed in one molecule forming an other asymmetric carbon atom.