Evaporation altered concentrations during the experiment.
Cut identical cylinders or discs of potato tissue to ensure uniform surface-area-to-volume ratios.
Proportional Dilution: Mixing specific volumes of a stock solution with distilled water to get targeted concentrations (e.g.,
Draw a complete box with clear vertical and horizontal boundaries. biology 9700 practical notes
Suggest using a colorimeter for color intensity, a thermostatically controlled water bath for temperature stability, or increasing the number of intermediate concentrations for a better trend line. 5. Critical Variables Independent Variable: What you change (e.g., pH). Dependent Variable: What you measure (e.g., volume of gas). Control Variables:
Add iodine in potassium iodide solution. A blue-black color indicates starch. Enzyme Kinetics Experiments usually involve catalase, amylase, or protease.
Print this box and memorize it 24 hours before your exam. Evaporation altered concentrations during the experiment
Improvement: Use a thermostatically controlled water bath instead of a manual beaker water bath.
: Used when you need specific concentrations at regular intervals (e.g., 2%, 4%, 6%). You calculate the volume of stock and distilled water for each. Serial Dilution
Add equal volumes of Benedict's reagent and sample. Heat in a boiling water bath ( 80∘C80 raised to the composed with power C 100∘C100 raised to the composed with power C Suggest using a colorimeter for color intensity, a
You must be intimately familiar with the following biochemical tests and physiological setups. Biochemical Tests (Food Tests)
is renowned for its rigorous theoretical depth, but the Paper 3 (Advanced Practical Skills) and Paper 5 (Planning, Analysis and Evaluation) often separate the top achievers from the rest.
Track the time it takes for a cloudy protein suspension to turn completely clear. Maintaining Controlled Variables
To minimize percentage uncertainty, modify your design to measure larger total quantities or switch to high-precision instruments with smaller graduation intervals. Identifying Variables
Connect data points directly with straight, ruled lines from point to point unless instructed to draw a smooth curve or a line of best fit. Never extrapolate your line beyond your first or last data points.