GCSE Biology (AQA)

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Rate of Decay

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Ecology Organisation of an Ecosystem

Rate of Decay

6:19 Decomposition
Spec 4.7.2.3
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  • Rate of decay can be decreased by limiting oxygen and water availability.
  • Sealed containers help restrict oxygen and water from reaching food, slowing decay.
  • Temperature also affects the rate of decay, with warmer temperatures generally increasing decay until it becomes too hot, which kills bacteria and denatures enzymes.
  • Decay rate can be calculated by observing changes in conditions such as temperature, pH, mass, or carbon dioxide levels over time.
  • Graphs can be used to calculate decay rates by measuring changes along the Y axis (decay rate) over changes along the X axis (time).
  • An example experiment involves keeping milk at various temperatures and measuring the pH change over time to determine the rate of decay.
  • The rate of decay is calculated as the change in value (e.g., pH) divided by the change in time, using data from experiments or provided data tables.
  • In exams, understanding how to calculate rate of decay involves interpreting data tables, applying the correct formula, and ensuring proper units are used in calculations.

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