Why store food in a fridge

Food is stored in a fridge to prevent (or slow down) the rate at which it perishes. Foods such as milk or butter will remain fresh for longer if stored in a fridge, but they decompose or otherwise go off more quickly if stored in a warmer environment. 

The natural processes that cause food to go bad occur because of enzymes and microbes, which react with the natural constituents of the food, and multiply. When 

The growth of each microbe and enzyme occurs with its own unique rate. A fridge acts by cooling the food in order to slow these rates to a more manageable level. At constant temperature, the rate of each reaction equals the respective rate constant k multiplied by the concentrations of all reacting species. For example, the rate of the reaction causing milk to go off occurs between lactic acid and an enzyme. The rate of the process is written formally as 

The rate constant k2 is truly a constant at a fixed temperature, but can vary significantly. 

The rate constant k2 is truly a constant at a fixed temperature, but can vary significantly increasing as the temperature increases and decreasing as the temperature decreases. This result explains why rate of reaction depends so strongly on temperature. 

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