Carbohydrates

• Basic formula of carbohydrates (saccharides)

  (CH₂O)n e.g. C₆H₁₂O₆
• Functions of carbohydrates

  Fuels, structure, recognition, nucleic acids
• Monosaccharides


  The simplest carbohydrates, molecules with one ketone or aldehyde group and multiple hydroxyl groups. Names end in -ose
• Monosaccharide examples

  glyceceraldehyde, dihyroxyacetone

  
• Are most monosaccharides D or L optical isomers?

  D
• How are hemiacetals and hemiketals formed?

  aldehyde + alcohol ⇌ hemiacetal

  ketone + alcohol ⇌ hemiketal
• What happens to pentoses and hexoses in solution

  They undergo cyclisation and form rings
• Aldohexoses form what type of ring

  Pyranose rings (six-membered)
• Ketohexoses form what type of ring

  Furanose ring (five-membered)
• What shapes are pyranose rings

  Chair and boat

  
• What shape are furanose rings

  Envelope

  
• Reducing sugars

  sugars containing a free aldehyde or ketone group
• bonds that join the anomeric carbon of one sugar and the hyroxyl group of another

  glycosidic bonds
• What groups of monosaccharides can be replaced

  OH