What is the difference between endothermic and exothermic reactions?

Endothermic reactions absorb energy, while exothermic reactions release energy.

Endothermic reactions are those that require energy to be absorbed in order to proceed. This means that the products of the reaction have more energy than the reactants. An example of an endothermic reaction is the reaction between baking soda and vinegar, which absorbs heat from the surroundings and causes the mixture to become colder.

Exothermic reactions, on the other hand, release energy during the reaction. This means that the products of the reaction have less energy than the reactants. An example of an exothermic reaction is the combustion of wood, which releases heat and light energy as the wood reacts with oxygen in the air.

The energy released or absorbed during a reaction is known as the enthalpy change. In an exothermic reaction, the enthalpy change is negative, indicating that energy is being released. In an endothermic reaction, the enthalpy change is positive, indicating that energy is being absorbed.

Understanding the difference between endothermic and exothermic reactions is important in many areas of biology, including metabolism and cellular respiration. These processes involve a series of chemical reactions that release or absorb energy, and understanding the thermodynamics of these reactions is essential for understanding how living organisms function.