Practical Notes | Biology 9700

Submerge reactions in a thermostatically controlled water bath. Subjective, biased visual judgment of a color change.

Drawing from years of examiner reports and marking schemes, here are the most important, actionable tips for your practical preparation: biology 9700 practical notes

You must know how to execute, interpret, and adapt standard qualitative and semi-quantitative tests to find unknown concentrations of biological molecules. Nutrient Type Reagent Used Positive Result Color Negative Result Color Key Procedural Requirement (e.g., Glucose) Benedict's Reagent →right arrow →right arrow →right arrow Heat in a water bath at 80∘C80 raised to the composed with power C 100∘C100 raised to the composed with power C for 5 minutes. Non-Reducing Sugars (e.g., Sucrose) Dilute HCl, NaHCO3NaHCO sub 3 , Benedict's Nutrient Type Reagent Used Positive Result Color Negative

Keep temperature constant using a thermostatically controlled water bath; keep pH stable using specific chemical buffer solutions. Osmosis & Water Potential ( ) Investigations Sucrose) Dilute HCl

To counter systematic weaknesses, suggest specific technical fixes: