Carbohydrates

• How does the structure of cellulose help it to form strong cell walls?

  Hydrogen bonds can form between adjacent cellulose chains.Cellulose chains group together to form microfibrils.In the cell wall the microfibrils form a lattice which gives tensile strength.

  
• How does cellulose form?

  B glucose molecules join together with gylcosidic bonds.Alternate B-glucose molecules flip (rotate through 180⁰) to allow this to happen.

  
• Cellulose

  A structural polysaccharide.Straight chains of B-glucose joined with 1-4 bonds.
• Glycogen


  Storage carbohydrate in animal and fungal cells.Highly branched chains of a-glucose.Stored in liver and muscle cells.Rapidly hydrolyses to release glucose.
• Why is starch a good storage molecule?

  Compact glucose store...due to branching and coiling.Insoluble...will not cause cell to draw water in by osmosis.Branches mean there are many terminal ends that are easily hydrolysed to rapidly release glucose.
• Amylopectin

  80% of starchBranched polymers of a-glucoseContain 1-4 and 1-6 bonds.1-6 bonds allow branches to form

  
• Amylose


  Straight, unbranched chains of a-glucose linked with 1-4 glycosidic bonds.Coil into a helix shape.

  
• Starch

  1. Polymer of aglucose2. Made of two different chains, amylose and amylopectin.3. Storage compound in plants.

  
• 3 Polysaccharides

  1. Starch2. Glycogen3. Celluose
• Polysaccharides


  Long chains of monosaccharides joined together through condensation reactions.(C₆H₁₀O₅)ₙNot sweetInsoluble
• Function of maltose and sucrose?

  Maltose is sugar found in grains.Sucrose is how carbohydrate is transported in plants.
• Maltose =Sucrose =


  Maltose = aGlucose + aGlucoseSucrose = aGlucose + Fructose
• Disaccharide formula and features.

  C₁₂H₂₂O₁₁Sweet and Soluble
• What does 1-4 Glycosidic bond mean?

  Bond forms between the first carbon of one molecule and the fourth carbon of the other molecule.
• Draw Formation of Maltose.

  
• Condensation Reaction


  Reaction that joins monomers together and releases water.

  
• Disaccharides

  Two monosaccharaides joined together in a condensation reaction by a glycosidic bond.

  
• Isomers

  Substances which have the same molecular formula but different structural formula e.g alpha and beta glucose.

  
• Glucose Function

  Energy source (used in respiration)
• beta glucose structure

  
• alpha glucose structure

  
• Glucose


  C₆H₁₂O₆Hexose Monosaccharide

  
• Monosaccharide

  The basic carbohydrate monomer..single sugars.1. Trioses...contain 3 carbons2. Pentoses...contain 5 carbons3. Hexoses..contain 6 carbons
• 3 Types of Carbohydrate

  1. Monosaccharide (1)2. Disaccharide(2)3. Polysaccharides (many)
• What elements do carbohydrates contain?

  Carbon, Hydrogen and Oxygen only.Ratio of Hydrogen:Oxygen is 2:1
• How do organic molecules form?

  Small sub units called monomers join together into polymers through the process of polymerisation.

  
• What are Organic molecules?

  Complex carbon containing molecules e.g Carbohydrates, proteins and lipids.