The Cellobiose molecule - rotatable in 3 dimensions

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Cellobiose is a disaccharide - formula C12H22O11 - consisting of two glucose units (12 carbon atoms, and 2 ring-shaped structures, each containing an oxygen atom) - like maltose.

However there are major differences between maltose and cellobiose:

Each glucose unit is effectively the opposite way up, a reflection of the arrangement in cellulose. This can be seen when the carbon 6 and associated groups are highlighted.

Additionally, the two sugars are linked via a differently oriented glycosidic bond - a β (beta) 1-4 bond - between opposite ends of the 2 glucose molecules. Label / unlabel bonding carbon atom numbers. This bond - effectively an oxygen bridge - is formed as a result of a condensation reaction.

This apparently linear linkage is the basis for cellulose, which forms microfibrils running parallel to others, stabilised by hydrogen bonds. Show ... hide H bonds between these sections.

Note that as in maltose, one of these ring-shaped sections is in equilibrium with an open-chain form in which Carbon 1 has a CHO aldehyde group which gives it reducing properties, so that it reacts with reagents such as Benedict's.



Possibly relevant
material available online
(from Amazon.com)

Possibly relevant
material available online
(from Amazon.co.uk)