PAGS

• calibrating eye piece graticule: use required lens magnification, line up eye piece graticule with the stage micrometer, count the number of divisions in 100 micrometres on the stage micrometer, 100 / number of eyepiece graticule divisions = length of 1 division in micrometres
• effect of enzyme concentration on rate of reaction: catalase + hydrogen peroxide, collect oxygen, change concentration
• effect of substrate concentration of rate of enzyme reaction: iodine in spotting tile, starch + amylase, pipette every 30 sec and record times, change starch concentration
• effect of temperature on rate of enzyme reaction: iodine in spotting tile, heat starch to set temperature, + amylase, pipette every 30 sec and record times, change starch temperature
• colorimetry for sugars: serial dilution, benedict's test, leave 24hrs, measure light through, create calibration curve
• amino acid chromatography, set paper, leave in solvent 24hrs, take out mark and dry, spray with ninhydrin, measure, use Rf equation
• biuret test: sodium hydroxide + copper (II) sulfate, blue -> purple = proteins
• purification of DNA by precipitation: mash, salt + dish soap, 60c 15 minute water bath, ice bath, filter, protease, ethanol, wire loop
• test for glucose: dip test strip compare, colour to chart

  used to test a persons urine for diabetes
• test for starch: iodine, orange -> blue = starch
• emulsion test: ethanol, clear -> cloudy = lipids
• reducing sugars test: benedict's reagent, boil, blue -> green -> yellow -> orange -> brick red
• non reducing sugars test: hydrochloric acid, boil, sodium hydrocarbonate, benedict's reagent, boil, blue -> green -> yellow -> orange -> brick red
• effect of temp on membrane permeability: heat beetroot cylinder at different temperatures in distilled water, test percentage absorbance of light in colourimeter with blue / green filter. The higher the temperature the higher percentage absorbance
• effect of pH on enzyme activity: iodine in spotting tile, add starch, pH buffer and amylase, pipette every 30 sec, change pH buffer
• create a blood stain slide: place a drop of blood a quarter way along the slide, use another slide to push into the drop and then pull back along the rest of the slide, leave to air dry, leave in ethanol for 2 minutes and blot, leave in Leishman dye for a minute and blot, add buffered water until the slide turns pink and blot
• how to use a light microscope: place slide on stage, use lowest objective lens, turn the coarse dial all the way and then use the fine focus until you are able to see the cells required, move to next objective lens
• Leishman dye


  a mixture of methylene blue and eosin
• examining a blood smear slide

  erythrocytes - red

  thrombocytes - purple grains

  lymphocytes - dark nuclei + blue cytoplasm

  neutrophils - dark nuclei + pink cytoplasm

  eosinophils - blue nuclei, pink cytoplasm + red granules

  basophils - dark nuclei + dark granules
• identifying lung tissue structures

  blood vessels - red, contain erythrocytes

  bronchioles - thin cell wall with smooth muscle and connective tissue

  alveolar sacs - clear gaps

  alveoli - small wiggly lines surrounding the gaps
• serial dilution

  mixing half of the previous solution with the same volume of distilled water to create a solution with half the concentration of the solution before

  
• investigation of water potential of a potato

  serial dilution of sucrose solutions, potato cylinders all same length, weigh each, add to different solutions, leave for an hour, reweigh, find percentage change of mass, plot graph, the lower the water potential the larger the change in mass
• osmosis in an artificial cell

  serial dilution of sucrose solution, cut dialysis tubing into equal lengths, fill with middle sucrose solution and knot, weigh, leave in 1st solution, reweigh, repeat for each solution concentration, calculate percentage change in mass and plot graph, if concentration is higher outside cell water will move out decreasing mass
• rate of diffusion through a membrane

  cut agar jelly containing universal indicator into different size cubes, put in same volume of acid, see how long it takes to fully change colour, calculate rate, draw graph