Table of Contents
Why do glucose fructose and mannose form the same osazone?
During osazone formation , the reaction occurs only at C1 and C2 while rest of the molecule remains intact, Since glucose and fructose differ from each other only in the arrangement of atoms at C1 and C2, therefore , they give the same osazone.
How glucose and fructose form the same osazone?
The adjacent −CHOH group is oxidized. Thus, we can here say that the aldose and ketose have the same osazone since they have the same structure at all carbons accept the C1 and C2 . For example, the glucose and fructose from the glucosazone, and fructosazone have a similar structure. Hence, (A) is the correct option.
Why do glucose and mannose and similarly galactose and talose form osazone derivatives with the same melting points?
Why do glucose and mannose, and similarly galactose and talose, form osazone derivatives with the same melting points? The configuration at C-2 of an aldose is lost in its osazone derivative, so aldoses dif- fering only at the C-2 configuration (C-2 epimers) give the same derivative, with the same melting point.
Why do glucose and fructose form the same osazone on treatment with excess of phenylhydrazine?
D-glucose, D-fructose and D-mannose form the same osazone treated with excess phenyl hydrazine because they differ only 1st and 2nd carbon atoms which are transformed to the same form.
What is osazone formation?
Osazones are a class of carbohydrate derivatives found in organic chemistry formed when reducing sugars are reacted with excess of phenylhydrazine at boiling temperatures.
Why do glucose and mannose form same osazones 2?
question_answer Answers(2) Formation of ozone involves only C1 and C2 carbon atoms. The rest of the carbon atoms remains uneffected. Glucose and fructose differ only in the configurations of first and second carbon atoms remaining positions are similar. So they form same osazone.
Why Osazone obtained from D glucose and D fructose have the same melting points?
Osazones are formed on reaction with excess phenylhydrazine . As glucose and fructose differs only in c1 and c2 configuration which gets disappeared after hydrolysis hence gives structurally same osazones.
How do the dimensions of cellulose and amylose compare?
Compare the dimensions of a molecule of cellulose and a molecule of amylose, each with an Mr of 200,000. Amylose forms helices, kind of like alpha helices, so it will be shorter and fatter. Cellulose forms fully extended straight sheets, kind of like beta sheets, so it will be longer and skinnier.
Which of the following pair gives the same osazone?
D−Glucose and D−fructose both form the same osazone.
Why reducing sugars produce osazone crystals?
Carbohydrates (sugars) are the most abundant organic molecules in nature. Sugars having reducing property react with phenylhydrazine hydrochloride to form characteristic osazones (crystals).
How is glucose converted into fructose?
Glucose is heated with excess of phenylhydrazine to form glucosazone. Fructose is reduced to hexitol by sodium‐amalgum(Na‐Hg)then oxidized with conc. HNO3 to hexanoic acid. Glucosazone upon hydrolysis with hydrochlorine acid yields glucosone and phenylhydrazine.
How does glucose and fructose react with phenylhydrazine?
Note:The reaction of glucose with phenylhydrazine gives glucose phenylhydrazone whereas the reaction of glucose with excess phenylhydrazine gives osazone. The sugar having free aldehyde or ketone groups is known as reducing sugars. All monosaccharides are reducing sugar. Glucose and fructose form the same osazone.