When you eat a sandwich and salad for lunch, your body eventually digests the food. The chemical processes that break down the nutrients in the meal are part of your metabolism. This creates fuel for the cells and provides energy for the entire body. Metabolism is a process that relies on multiple reactions.
TL;DR (Too Long; Didn't Read)
During reactions that make up a living being’s metabolism, existing chemical bonds can break, and new bonds can form. This activity also releases energy that is important for the organism's survival.
Metabolism and Chemical Bonds
Metabolism describes the chemical reactions taking place inside your cells. Existing chemical bonds are important for this process because they break or form to release energy. Breaking chemical bonds does use some energy, but the break and the resulting products, which form new bonds, provide energy for the cell.
For instance, when you eat an orange, the digestive system breaks it down with the help of enzymes. This releases carbohydrates from the orange. Next, your body can transform the carbohydrates into simple sugars and use them as an energy source. The simple sugars can travel to different cells in the body to help you walk, dance or engage in other activities.
Catabolism and Anabolism
Metabolism relies on two main types of reactions: catabolism and anabolism. Catabolism releases energy in the body. In catabolic reactions, molecules such as carbohydrates break down, and bonds break. Your body needs this energy to function. For example, when you are shivering from the cold, catabolic reactions can create heat to keep you warm.
Anabolism takes energy and helps you grow. Anabolic reactions use energy to build complex molecules such as fat by creating new bonds. For example, these reactions can help your muscles grow and get bigger.
What Affects Metabolism
Many things can affect your metabolism such as temperature. Enzymes and hormones can also influence the chemical reactions that are part of metabolism in the body. Even toxins can affect it by slowing it down or interfering with the process.
Some common disorders of metabolism are hyperthyroidism and hypothyroidism. If you have hyperthyroidism, then the thyroid gland is overactive and creating too much of the thyroxine hormone. This means the basal metabolic rate (BMR) is too high, so your body burns energy faster. On the other hand, if you have hypothyroidism, then the thyroid gland is underactive and not making enough hormones. This makes the BMR too low, so you gain weight easier and have trouble losing it.