carbohydrates and tests for

• What type of monosaccharide is glucose?

  Hexose - monosaccharide, meaning that it has 6 hydrogen bonds.
• Draw the structure of Alpha glucose. ?

  .

  
• Draw the structure of Beta glucose?

  .

  
• What type of molecule (in terms of relative charge) is glucose?

  A polar molecule.
• Why is it important that glucose is a polar molecule?

  As it is soluble in water, due to the hydroxyl (OH) groups which interact with water, it can be dissolved in the cytosol of the cell.
• Which direction are the hydrogens numbered on a glucose molecule?

  Clockwise
• Describe a condensation reaction between 2 alpha glucose molecules. ?

  When two alpha glucose molecules are side by side the hydroxyl (negative charge) groups interact with eachother.

  A 1-4 glycosidic bond, a type of covalent bond, is formed and water is a by product.

  Maltose a disaccharide is produced.
• Describe a hydrolysis reaction between Beta glucose molecules?


  When beta glucose molecules are aside on another, in order to react alternating molecules are required to be at an 180° angle. This is so the hydroxyl groups are close enough to interact.

  They interact for form a 1-4 glycosidic bond (type of covalent bond) and create a long polysaccharide chain.

  When the chain is formed in a straight way, the product is called cellulose.
• Describe cellulose?


  A long polysaccharide chain of Beta glucose molecules joined by 1-4 glycosidic bonds.

  Cellulose makes hydrogen bonds with eachother, forming microfibrils.

  Microfibrils join together to from macrofibrils.

  Macrofibrils combine to produce fibres, which are hard to break down and are an important part of our diets.
• Describe ribose and deoxyribose?

  Pentose monosaccharide- 5 hydrogen bonds.

  Ribose is present in RNA nucleotides

  Deoxyribose is present in DNA nucleotides.

  Deoxyribose has one less oxygen than ribose, ribose consists of a hydroxyl group at carbon 2, instead deoxyribose has a hydrogen atom at carbon 2. Because of this deoxyribose is more stable than ribose.
• What is glycogen, describe its properties?

  Glycogen is the functionally equivalent energy store of starch in animals.

  Glycogen contains both 1-4 glycosidic bonds and 1-6 glycosidic bonds. However it contains many more 1-6 bonds than amylopectin, making it much more compact and less space is needed for it to be stored. This is important as animals are mobile, unlike plants, so require more energy.

  The end of the branches have many free ends.
• what are nucleic acids?


  large molecules which were discovered in the cell nuclei, there are two types DNA and RNA
• Large polymer


  A polymer made up of many monomers
• Nucleotides


  Monomers which make up nucleic acids
• Components of nucleotides

  • Sugar
  • Phosphate
  • Nitrogenous base
• Condensation reactions

  Nucleotides are linked together by condensation reactions to form a polynucleotide
• Polynucleotide


  A large polymer formed by the linking of nucleotides through condensation reactions
• Polynucleotides form covalent bonds between nucleotides
• what is the subunit for cellulose? beta glucose
• what is the subunit for starch (amylose and amylopectin)?

  alpha glucose
• what is the subunit for glycogen?

  beta glucose
• what are the bonds in cellulose and amylose?

  1-4 glycosidic bonds
• what are the bonds in amylopectin and glycogen?

  1-4 glycosidic bonds and 1-6 glycosidic bonds.
• describe the branches of amylopectin and glycogen?

  the branched structure is caused by 1-6 glycosidic bonds.

  in amylopectin these occur every 20 alpha glucose subunits

  in glycogen these occur every 10 beta glucose subunits
• why is glycogen important?

  glycogen is used as storage of glucose which allows for fast energy release when needed

  • present in muscle tissues
  • many branches allow for rapid hydrolysis, to provide high levels of glucose more quickly, allowing for more respiration during exercise
• why is amylopectin important?

  used a an energy store in plants

  • organised branched structure allows many glucose units to be synthesised and stored effectively in the starch granule
• why is amylose important?

  plant energy storage

  • less readily digested than amylopectin; however because of its helical structure, it takes up less space than amylopectin. As a result is the preferred starch for storage in plants
• why is cellulose important?

  • main substance in the walls of plants
  • helps plants to remain stiff and upright
  • humans cannot digest cellulose, but it is important in the diet as fibre