🍝 Carbohydrates (CCEA)


Monomers and Monomers

Glucose

Glycosidic bonds

Alpha Vs Beta Glucose

Storage of Carbohydrates inΒ Mammals


Introduction

Carbohydrates as well as proteins are polymers and contain only a few different types of atom. In the case of carbohydrates, the basic molecular units are called monosaccharides – these are the monomers. (mono = single; poly = multiple; saccharide = sugar)

Ξ± (alpha) glucose is one of three important monosaccharides to learn, as you need to be able to draw it:

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Glucose is a key carbohydrate in biology because it is the preferred fuel that provides energy during cellular respiration as well as the building block for complex polysaccharides and other compounds that use it such as glycoproteins. As a monomer, it is small and water soluble and thus accessible to cells for respiration. Plants and other organisms can create it through photosynthesis. It can be built into starch or glycogen and stored away for later use. When required, it can be obtained by breaking starch or glycogen down again. This is what maintains blood sugar levels.

The points where the lines intersect each symbolise a carbon (C) atom. You need not show those. The figure above is taken from the specification itself, so take it as a good guide. So the monosaccharide alpha glucose (commonly, just glucose) somehow becomes a polysaccharide, This is achieved by condensation reactions, and the bonds formed are called glycosidic bonds.

You should be able to draw this. The resulting molecule, maltose, is a disaccharide (two monomers). If you keep adding glucose molecules to the chain, you get… *drum roll please* …starch. Starch is made up of multiple (very many indeed) monomers….