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