bio t1

• Define a monomer?


  ~ one of many small molecules that combine to form a larger one known as a polymer
• Define a polymer?


  ~ large molecule made up of repeating smaller molecules(monomer)
• 4 examples of monomers?

  ~ Monosaccharides- Glucose, galactose

  ~ Nucleotides

  ~ amino acid

  ~ fatty acid or glycerol
• Define a hydroylsis reaction?

  ~ the breaking down of large molecules into smaller ones by the addition of water molecules
• Define a condensation reaction?

  ~ chemical process in which 2 molecules are combine to form to form more complex one with the elimination of a simple substance usually water. polymers are form through this reaction.
• Define monosaccharides?


  ~ A monomer of carbohydrates
• Define dissacharides?


  ~ A molecule that is made up of two monosaccharides
• Define polysaccharides?


  ~ A molecule formed from more than two monosaccharides
• Draw a Beta glucose?

  
• Draw alpha glucose?

  
• What type of sugar is a glucose?

  ~ Hexose sugar
• What is a Sucrose made up of?

  ~ Fructose & Glucose
• What is Maltose made up of?

  ~ Glucose & Glucose
• What is Lactose made up of?

  ~ Glucose & Galactose
• Describe the structure of amylose?

  ~ Long, unbranched chains of α-glucose

  ~ Angles of glyosidic bonds makes it a coiled structure - this makes it compact and good for storage

  ~ Amylose is insoluble so does not effect water potential

  ~ Contain 1-4 glyosidic bonds
• Describe the structure of amylopectin

  ~ Long, unbranched chains of α-glucose

  ~ Has side branches which allows enzyme to hydrolyse bonds more easily - glucose is released quickly

  ~ Amylopectin is insoluble so does not effect water potential inside a cell

  ~ Contain 1-4 glyosidic bonds

  ~ Branches with 1-6 glyosidic bonds
• Function of amylopectin & amylase?

  ~ Cells get energy from glucose

  ~ Plants store excess glucose as starch - when glucose is needed the starch is broken down
• Structure and function of Glycogen?


  ~ shorter , unbranched chains of α-glucose

  ~ highly unbrached chains amylopectin

  ~ Very compact molecule so good for storage

  ~ Glycogen is insoluble so does not effect water potential inside a cell

  ~ Smaller chains of 1-4 glyosidic bonds

  functions:

  Loads of side branches means that glucose can be released quickly to provide energy

  ~ Way excess glucose is stored in animals

  storage for excess sugar in liver
• Function of Glycogen?


  storage for excess sugar in liver
• Describe the structure of cellulose?


  ~ Long, unbranched chains of β-glucose

  ~ Glyosidic bonds makes a straight chained molecule

  ~ Cellulose chains are linked together by hydrogen bonds - forming microfibrils

  ~ Microfibrils are further bunched together to form macrofibrils
• Function of cellulose?


  ~ The strong macrofibrils means cellulose provides structural support for cells - cell walls for cells are turgid
• Biochemical test for a reducing sugar?

  ~ Add benedicts reagent and heat it in a water bath

  ~ Positive result will form a brick red precipitate
• Biochemical test for a non-reducing sugar?

  If test for reducing is negative then do this:

  ~ Add dilute hydrochloric acid to the sample and heat it in a water bath - to break non-reducing sugars down into monosaccharides

  ~ Neutralise with sodium hydrocarbonate

  ~ Carry out Benedict's test
• What is a reducing sugar?

  ~ All monosaccharides

  ~ Some disaccharides - Maltose & Lactose
• What is a non-reducing sugar?

  ~ Some disaccharides like sucrose
• Describe the test for starch (E.g. amylopectin & amylose)?

  ~ Add iodine dissolved in potassium iodide solution to the sample

  ~ Positive result means it will go from browny-orange to a blue-black colour
• Describe the structure of triglycerides?

  ~ Have one molecule of glycerol with 3 fatty acids attached

  ~ Fatty acids made of hydrocarbons

  ~ The tails are hydrophobic so makes triglycerides insoluble
• How does a disaccharide form?

  ~ Joined by a condensation reaction forming a glyosidic bond

  ~ A molecule of water is released
• Draw A triglyceride

  
• Describe the differences between a saturated and unsaturated fatty acid?

  ~ Saturated fatty acids don't have any double bonds between their carbon atoms while a unsaturated does
• How is a triglyceride formed?

  ~ By a condensation reaction between fatty acids and a glycerol

  ~ Ester bond is formed and a molecule of water is removed
• Draw a diagram of a phospholipid?

  
• Where are the hydrophobic & hydrophilic regions on a phospholipid?

  ~ Hydrophobic fatty acid tail

  ~ Hydrophilic phosphate group
• Describe the test for lipids?

  Called the emulsion test

  ~ Shake the test substance with ethanol and then pour into water

  ~ Any lipids present will show up as a white emulsion

  ~ The greater the presence of emulsion means more lipids present
• Relate the structure of triglycerides to their function?

  ~ Mainly used a energy storage molecules - good because they have long hydrocarbon tails which contain lots of chemical energy. When broken down they release twice as much energy as carbohydrates

  ~ They are insoluble in water so do not effect water potential - which causes water to enter by osmosis - As triglycerides bundle into insoluble droplets as the tails are hydrophobic
• Draw a insoluble triglyceride droplet?

  
• Relate the structure of a phospholipid to its function?

  ~ Make up a bilayer of cell membranes controlling what enters and leaves cell - As the tails are hydrophobic so point inwards and the heads a hydrophilic so point into water.

  ~ So allows membrane to be a barrier as water-soluble substances can't easily pass through
• Draw the general structure of a amino acid?

  
• How many different types of amino acids are there?

  ~ Only 20 different types
• Define polypeptide?


  ~ A molecule formed from more than 2 amino acids bonded by peptide bonds