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Explain the principle of mutarotation and in which osides it occurs.
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Mutarotation is the change in the optical rotation around the carbon anomérique in reductive osides such as maltose and lactose.
Which diolosides are non-reductive, and why?
Saccharose and tréhalose are non-reductive because their structure does not have a free reactive ose.
Which osidic bond is present in maltose and lactose making them reductive?
Both maltose and lactose have a 1,4 osidic bond that allows them to have a free anomeric carbon, qualifying them as reductive.
What enzymes are involved in the hydrolysis of saccharose?
The enzymes involved are alpha-glucosidase and bêta-fructosidase.
What distinguishes homopolysaccharides from heteropolysaccharides?
Homopolysaccharides are composed of identical oses, whereas heteropolysaccharides consist of different types of oses.
Why is raffinose considered a non-reductive oside?
Raffinose is considered non-reductive because it does not present a free reactive ose group that can exhibit reduction.
Identify two enzymes that hydrolyze lactose and their role.
Lactose is hydrolyzed by alpha-glucosidase and beta-galactosidase, which break down its galactose and glucose components.
What differentiates maltose from trehalose in terms of reducing capability?
Maltose is a reductive disaccharide due to its structure allowing a free anomeric carbon, unlike trehalose which is non-reductive.
What type of osides comprise 2 to 10 oses?
These are called oligosides.
What role do polysaccharides like cellulose, glycogen, and starch play in biological systems?
They are energy storage molecules, structural components, and serve various roles in different organisms.
How do the presence of beta or alpha anomères affect osidic activity?
The type of anomère (alpha or beta) affects the structural bonding and enzyme interaction of the osides, determining its biological activity.
Describe the structural feature required for the formation of an osidic bond.
An osidic bond forms between the hydroxyle reducteur of an ose on the carbon anomérique and a hydroxyle of another ose, and requires an asymmetric carbon.
What is the significance of the carbon anomérique in osides?
The carbon anomérique is crucial for the formation of the osidic bond, which determines if an oside is reductive or not.
What is the key structural trait of a polysaccharide?
A polysaccharide is composed of more than 10 oses.
Describe the type of bond in saccharose and its implications on its reducing property.
Saccharose has a 1,2 osidic bond that prevents it from being reducing as both anomeric carbons participate in bonding.
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