3) After watching the video convert the monosaccharides from a Fischer to a Haworth Projection. a) Convert D-mannose to its a-pyranose. CHO + -H 2 HO-H HO H- -OH OH CH₂OH H- 6 D-mannose b) Convert L-galactose to its B-pyranose. 'CHO HO-H HOH H-OH HO-SH 6CH₂OH L-galactose
Fischer and Haworth Projections
Fischer and Haworth projections are two ways of representing the structure of carbohydrates, especially monosaccharides (simple sugars). They are both two-dimensional projections, but they show different aspects of the carbohydrate molecule.
Fischer projections show the carbohydrate in its open-chain form, with the carbon atoms in a vertical line and the hydroxyl (OH) and hydrogen (H) groups on either side. The stereochemistry of the molecule is indicated by the position of the OH and H groups. A horizontal bond indicates a group that is pointing out of the plane of the page, while a vertical bond indicates a group that is pointing into the plane of the page. I am not going into the details of the rules that govern drawing Fischer projections.
Haworth projections show the carbohydrate in its cyclic form, which is the form that it exists in most of the time in solution. The ring is represented as a hexagon, with the carbon atoms at the corners and the OH and H groups on the sides. The stereochemistry of the molecule is indicated by the position of the OH and H groups relative to the ring.
Step by step
Solved in 4 steps with 5 images
