Biology

• cells are - 


  the basic building blocks of all living things
• tissues - 


  group of cells with a similar structure and function
• organ - 


  combination of tissues carrying out a specific function
• organ system - 


  where organs work together
• organism -


  organ systems work together to form whole living organisms
• what indicator do you use for the test for sugar

  Benidict's raegent
• which indicator do you use for the test for starch

  iodine
• which indicator do you use for the test for protein

  buiret
• which indicator do you use for the test for lipid

  sudan III
• what would a positive result for the test for sugar

  once heated the solution will change from blue-green to yellow-red
• what would a positive result look like for the test for starch

  blue-black colour indicates starch is present
• what would a positive result look like for the test for protein

  the solution will change from blue to pink-purple
• what would a positive result look like for the test for lipid

  the lipids will seperate and the top layer will turn bright red
• what is the independent variable in the test for starch

  pH of buffer solution
• what is the dependent variable in the test for starch 


  time taken for the reaction to complete ( how long it takes for the starch to be digested completely by the amylase )
• what is the first step for the test for starch

  use the marker pen to label a test tube with the first value of pH buffer solution ( pH 4 ) and stand it in the test tube rack
• what is the second step of the test for starch 


  into each well of the spotting tiles, place a drop of iodine
• what is the third step of the test for starch

  use a measuring cylinder, measure 2cm³ of amylase and pour into the test tube
• what is the fourth step of the test for starch

  using a syringe, measure 1cm³ of the buffer solution and pour into the test tube
• what is the fifth step of the test for starch

  leave this to stand for 5mins and then use a thermometer to measure the temperature. Make a note of the temperature
• what is the sixth step of the test for starch

  add 2cm³ of starch solution into the test tube, using a different measuring cylinder and begin a timer ( leave timer to run continuously)
• what is the 7th step of the test for starch

  after 10 seconds use a pipette to extract some of the amylase / starch solution and place one drop into the first well on the spotting tile. squirt the remaining solution back into the test tube
• what is the 8th step in the test for starch 


  continue to place one drop into the next well of the spotting tile every 10 seconds until the iodine remains orange.
• what is the 9th step of the test for starch 


  record the time taken for the starch to be completely digested by the amylase by counting the wells that were tested positive for starch ( indicated by the blue/black colour change of the iodine ) . Each well represents 10 seconds of time.
• what is the 10th step of the test for starch 


  repeat steps 1 - 8 for pH values 7 and 10