How to improve simple experiments - · PDF fileWater potential of potato •Use mannitol or...
Transcript of How to improve simple experiments - · PDF fileWater potential of potato •Use mannitol or...
How to improve simple experiments
Rate of photosynthesis
Quantitative IV and DV Qualitative IV and DV
Vitamin C content of fruit /vegetables
Connect with problems:
• Compare different cooking methods: streaming, boiling, microwaving
• Verify the vitamin C content of vitamin C tablet
Vitamin C titration with potassium iodate
Water potential of potato
• Use mannitol or salt solution to replace sucrose solution
• Replicate with different potato tubers
• Use Chardakov method to check the result
Sucrose solution with potato
Add a drop of methylene blue after 0.5 hour
Release a drop of the blue solution in
same conc. of sucrose solution
Chardakov method
Transpiration rate • DVs: water absorption & weight
• IVs: light intensity, wind speed, leaf surface area, upper/lower epidermis
• Quantitative measures of IV: light intensity by light meter, wind speed by anemometer
• Within or between subject design
• Replications with more shoots
• Use dye in place of water to identify xylem in stem
• Count the density of stomata in upper/lower epidermis
Amylase activity
• IV: pH, T, amylase conc.
• Measure amylase activity:
Time for complete hydrolysis of starch as detected by repeated iodine test
Amount of starch hydrolyzed in a fixed period of time
Amount of maltose produced as detected by DNS
Amount of maltose detected by DNS
Absorbance =Log10(I0/I)
Thank you!
Turning biotech experiments into SBA investigations
Digestion and ligation of plasmids
Check transformation of bacteria
control