Carbohydrates II

Monosaccharides

D-glyceraldehyde molecular structure

L-glyceraldehyde molecular structure.

Mirror images of each other.

D-glucose

carbon C1 and C5 approach

Pyranose ring.

α-D-glucopyranose.

β-D-fructofuranose.

D-glucosamine

Disaccharides

2 glucose molecules approach.

1 water molecule is lost

a glycosidic bond is formed.

Maltose shows a α-glycosidic bond

Cellobiose shows a β-glycosidic bond, like sucrose.

Polysaccharides

• Starch
  • Amylose

Maltose (2 residues of glucose)

We add a 3rd, 4th, 5th and 6th residues.

Activate rotation to observe helical structure

Zoom out and addition of more glucose residues to reach a 30 residues molecule

Look from a polar view.

• • Amylopectin.-

A fragment of amylopectin including 5 glucose residues.

Zoom in to show a Branch point

4 residues at branch point.

By adding to initial structure 25 glucose residues we get a 30 residues amylopectin fragment.

Zoom out to show that branch points are spaced by 24-30 glucose residues.

• Glycogen.- Structure like amylopectin but with branch points spaced by 8-12 glucose residues.

• Cellulose.-

See cellulose.

• Chitin.- A polymer of β-N-acetil-D-glucosamina.

A 3 residues chitin fragment.

• Hyaluronic acid.- Heteropolysaccharide with alternating residues of β-N-acetil-D-glucosamine and glucuronic acid

Files for 3D printer

Alpha-amylase with flexible amylopectin by Marius Mihasan