Biological molecules

• What is a monomer?


  Small basic units that join together to make a polymer.
• What is a polymer?


  Long chained molecule made up of many monomers.
• How does one monomer join together to form polymers?


  Condensation reactions
• What is removed from a condensation reaction?


  Water
• What is a hydrolysis reaction?

  Hydrolysis reaction is the use of water to split the bonds in a polymer.
• What is a monosaccharide?

  A simple carbohydrate monomer.
• What are isomers? 


  Molecules that have the same molecular formula but different structural formulas.
• What are the three main monosaccharides? 


  -Glucose

  -Galactose

  -Fructose
• What is an alpha glucose?


  It is when hydrogen is above the ring.
• What is a beta glucose?


  It is when hydrogen is below the ring.
• What two monosaccharides are lactose made from?


  -Galactose

  -Alpha glucose
• What two monosaccharides are Sucrose made from?

  -Fructose

  -Alpha glucose
• What are disaccharides?


  When two monosaccharides are joined together by a glycosidic bond
• What is a glycosidic bond?


  When two monosaccharides join together in a condensation reaction, thus removing water and is now joined by oxygen.
• What are the products of two monosaccharides joined together?


  Disaccharide and water.
• What is hydrolysis?

  The use of water to split up disaccharides.
• What are enzymes?


  Biological catalysts which speed up the rate of a chemical reaction by lowering the activation energy, without being used up.
• Hydrolysis is catalysed by...


  enzymes
• Maltase catalyses the hydrolysis of maltose into...


  two alpha glucose molecules
• Lactase catalyses the hydrolysis of lactose into...


  galactose and alpha glucose
• Sucrase catalyses the hydrolysis of sucrose into...


  fructose and alpha glucose
• Amylase catalyses the hydrolysis of starch into...


  Maltose
• What are polysaccharides?

  A polysaccharide is a polymer of monosaccharides joined by condensation reactions and held together by glycosidic bonds.
• What are the three types of polysaccharides?

  Starch, cellulose and glycogen
• What is starch?

  It is an insoluble, storage molecule found in plant cells. Since it is insoluble it does not cause water to move into cells by osmosis, therefore it does not affect the water potential of the cell. It is a mixture of two types of polysaccharides - Amylose and amylopectin.
• What are the two types of polysaccharides starch is made from?


  Amylose and amylopectin
• Describe the structure of amylose.

  -It is helical and unbranced allowing it to be compact so that a lot of it can fit into a small space.

  -Contains 1-4 glycosidic bonds so therefore it is linear.
• Describe the structure of amylopectin.

  -Made up of 1-4 and 1-6 glycosidic alpha glucose molecule bonds meaning that it is branched. (1-4 glycosidic bonds show where it is linear and 1-6 glycosidic bonds show where it is branched)
• How is the structure of amylopectin adapted for its function?

  -It is branched to allow enzymes to easily access the glycosidic bonds and hydrolyse them for the quick release of glucose.
• Why is amylopectin branched?


  To hydrolyse the glycosidic bonds to allow the quick release of glucose.
• Describe the structure of glycogen.

  -It is insoluble and will not cause water to move into cells by osmosis and so it does not affect the water potential of the cell.

  -The branches are evidence of 1-4 and 1-6 glycosidic bonds.

  -More highly branched than amylopectin.
• How is the structure of glycogen adapted for its function?

  -It is compact so that it allows a lot of it to fit into a small space.

  -It has many side branches to allow for faster hydrolysis of glycosidic bonds and release of glucose for aerobic respiration which generates ATP.
• Describe the structure of cellulose

  -It is a polymer of beta glucose. Many cellulose molecules are joined together by hydrogen bonds.

  -Every other beta glucose molecule is inverted so that 1-4 glycosidic bond can be formed between them and the cellulose molecule will be linear.
• Cellulose is a polymer of...


  beta-glucose
• Cellulose are joined together by...


  hydrogen bonds
• How is the structure of cellulose adapted for its function?

  One hydrogen bond is weak. Many hydrogen bonds together are strong. This provides structural support making cellulose cell walls strong.
• What two monosaccharides is maltose made from

  -Alpha glucose

  -Alpha glucose
• How is cellulose made from beta glucose molecules?

  Every other beta glucose molecule is inverted so that a 1-4 glycosidic bond can be formed between them and so that the cellulose molecule is also linear.
• What is a reducing sugar? 


  Reducing sugars act as reducing agents in chemical reactions by donating electrons to other molecules.
• What are some examples of reducing sugars?

  All monosaccharides and some disaccharides (lactose and maltose)