Monosaccharides

• what are monosaccharide?

  they are small organic molecules and are the building blocks for the the larger carbohydrates
• whats the general formula for monosaccharides?

  (CH2O)n

  ’n’ is the number of carbon atoms in the molecules
• what are 3 examples of monosaccharides?

  triose, pentose and hexose
• what do all hexose sugars share and differ in?

  share: the same formula (C6H12O6)

  differ: molecular formula
• what happens to carbon atoms of monosaccharides when dissolved in water?

  they make a ring when the sugar is dissolved in water and they can alter their binding to make straight chains, with the rings and chains in equilibrium
• what are the isomers of glucose and what do they cause?

  isomers: a-glucose and B-glucose

  effect: these different forms result in biological differences when they form polymers, such as starch and cellulose
• Whats the definition of an isomer?

  Molecules that have the same chemical formula but a different arrangement of atoms
• what does this structural formula show?

  alpha-glucose

  
• what does this structural formula show?

  beta-glucose

  
• what are the functions of monosaccharides?

  • a source of energy in respiration (C-H and C-C bonds are broken to release energy thats transferred to make ATP)
  • building blocks for larger molecules (e.g. glucose is used to make the polysaccharides starch, glycogen, cellulose and chitin)
  • intermediates in reactions (e.g. trioses are intermediates in the reactions of respiration and photosynthesis)
  • constituents of nucleotides (e.g. deoxyribose in DNA, ribose in RNA, ATP and ADP)