AI Explain

• What is the calculation required for an eyepiece graticule?

  no. of units x micrometres/units

  no. of units x micrometres/units= actual length
• What is the max resolution of a light microscope?

  0.2 micrometres
• what is the max magnification of a light microscope?

  x1500
• What does a transmission electron microscope do?


  it detects electrons transmitted through sample surface
• what is the max resolution of a transmission electron microscope?

  0.0002 micrometres
• what is the max magnification of a transmission electron microscope?

  x 1,000,000
• what images do TEMs produce?

  2D images of internal cell structure
• what does a scanning electron microscope do?

  detects electrons that bounce off the sample's surface
• what is max resolution of a scanning electron microscope?

  0.002 micrometre
• what is the max magnification of a SEM?

  less than x500,000
• what images do SEM produce?

  3D images of the outer cell surface
• what is a colorimeter


  an apparatus that measures absorbance or transmission of light through a sample
• what are three things an amino acid structure consists of?

  an R group, carboxyl group and amine group
• what are the four levels of the protein structure?


  primary, secondary, tertiary and quaternary
• what is the primary structure of proteins?

  the sequence of amino acids
• what bonds does the primary structure of proteins consist of?

  peptide bonds
• what is the secondary structure of proteins?

  the folding of the polypeptide chain
• what are the common types of secondary structures?

  alpha helix and beta pleated sheet
• what bonds are involved in a protein's secondary structure?

  hydrogen bonds
• what is a protein's tertiary structure?

  the 3D folding of a polypeptide chain
• what bonds are involved in a protein's tertiary structure?

  hydrogen bonds, ionic bonds, hydrophobic and hydrophilic interactions
• what is a protein's quaternary structure?

  when 2 or more polypeptide chains are joined together
• what are the features of cellulose?

  uses beta 1,4 bonds and is a straight chain
• name one function of cellulose.


  provides rigidity in cell walls
• name features features of starch/glycogen.

  they use alpha 1,4 and 1,6 bonds and so are coiled and branched molecules
• what is the coiled molecule of starch/glycogen and what bonds does it use?

  amylose and it uses alpha 1,4 bonds
• what is the branched molecule of starch/glycogen and what bonds does it use?

  Amylopectin and it uses both alpha 1,4 and 1,6 glycosidic bonds
• what is a function of amylose?

  they are suitable for storage molecules as they are coiled/compact and therefore insoluble
• what is a function for amylopectin?

  they are suitable for respiration as they are highly branched and so have many ends to be broken down by hydrolysing enzymes.
• what is the structure of triglycerides?

  consists of one glycerol molecule and 3 fatty acid tails
• name functions of triglycerides.

  1. good source of energy 2. energy storage molecule 3. provides thermal and electrical insulation
• what is the test used to detect reducing and non reducing sugars?

  Benedict's test
• what is an example of reducing sugars?

  all monosaccharides
• how is a benedict's test carried out to detect a reducing sugar?

  first you grind the sample, then you add the same volume of benedict's reagent and then heat it
• what colour shows a positive result of the Benedict's test for reducing sugar?

  goes from a blue to an orange/brown
• describe the steps of a benedict's test for NON REDUCING SUGARS.

  first you grind the sample with water, then you add an acid to it and boil the solution, then you neutralise it with an alkali and finally add benedict's reagent and heat it up
• what is the test used to detect proteins?

  biuret test
• describe the steps of a biuret test.

  first you add the sample and an equal volume of sodium hydroxide to it then you add a few drops of copper sulfate solution and mix it gently.
• what is a positive result in a biuret test?

  purple
• what are two features of globular proteins?

  they are globe-like and soluble in water