This key facts covers Calculation Skills: Enzyme Rates within Enzymes in Digestion for GCSE Biology. Enzyme structure and function, digestive enzymes, factors affecting enzyme activity, lock and key model, and practical investigations It is section 12 of 19 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 12 of 19
Practice
20 questions
Recall
25 flashcards
Calculation Skills: Enzyme Rates
Rate of Reaction
Formula: Rate = Amount of product formed ÷ Time taken
Units: mol/s, g/s, cm³/s, etc.
Example Calculation
In an enzyme experiment, 20 cm³ of oxygen is produced in 2 minutes.
Rate = 20 cm³ ÷ 2 min = 10 cm³/min
Or in seconds: 10 cm³/min ÷ 60 = 0.17 cm³/s
Initial Rate
- Calculated from the steepest part of the graph (usually the start)
- Draw a tangent to the curve at time 0
- Calculate gradient: rise ÷ run
Q10 Temperature Coefficient
Formula: Q10 = Rate at (T + 10°C) ÷ Rate at T°C
Example: Rate at 30°C = 5 units, Rate at 20°C = 2 units
Q10 = 5 ÷ 2 = 2.5 (rate increases 2.5 times for 10°C increase)