When chemical bonds in reacting molecules are broken during metabolism, energy is required, whereas chemical bonds in reacting molecules that form during metabolism will actually exert energy. During metabolism, the relative strengths of the bonds that are being broken and formed will influence the type of reaction that is happening and the likely results. In an exergonic reaction, energy is being released whereas in an endergonic reaction, energy is being absorbed.
There are two different types of metabolic activities that happen within a cell — anabolism and catabolism. Anabolism is when energy is being used up and small molecules, like monomers, are being joined and linked together in order to create larger molecules, like polymers. Catabolism is when energy is being released into the environment. This generally happens when larger molecules, such as polymers, are broken down into smaller molecules, like monomers.
The type and rate of metabolic activity that happens in a cell will be influenced by the temperature of the surrounding environment. Metabolic activity has been known to slow down during colder temperatures, since the proteins and molecules tend to move at a slower speed and will take longer to react with one another. In comparison, at higher temperatures, the molecules have a higher kinetic energy, are moving much quicker, and will generally react within a shorter time frame.