Alpha & Beta Glucose: How to Differentiate

[UNknown 2010]

Hi all,

I find difficulties in recognizing between alpha and beta Glucose.

Can anybody explain briefly how can I differentiate between them ?

 

[UNknown 2010]

Another question:

How can I recognize between Sucrose & Maltose ?

 

[Ygggdrasil]

In β-glucose, the CH₂OH and the OH on the anomeric carbon are on the same side of the ring (e.g. they are either both above the plane of the ring or below). In α-glucose, the CH₂OH and the OH on the anomeric carbon are on opposite sides of the ring (e.g. if the CH₂OH is shown above the plane of the ring, then the anomeric OH should be below). A good way to remember this is to associate α with anti.

The anomeric carbon is the carbon atom in glucose that has two bonds to oxygen.

Maltose is formed from two glucose monomers and sucrose is formed from a glucose and fructose. The easiest way to distinguish between them is to remember that glucose forms a six-membered ring whereas fructose forms a five-membered ring.

 

[UNknown 2010]

Thank you very much :)

So β-glucose & α-glucose are geometric isomers ?

 

[Ygggdrasil]

Yes, it would be correct to refer to them as geometric isomers.