Metabolism consists of a system of chemical reactions that take place in the cells of our bodies.

Metabolism is converting fuels in our food that we’re eating into the energy that we need for powering all the things we do, from thinking to moving to growing.

There are specific proteins in our bodies that control all chemical reactions when Metabolism occurs, and all chemical reactions are in accordance with any other body function.

Several thousands of metabolic reactions are happening simultaneously, and all are regulated by our bodies, maintaining our body cells working and healthy.

The process of Metabolism is constant, and it started already when we were conceived, and it stops when we will die. Metabolism is an absolutely vital process for all forms of life, and not just within humans. When Metabolism ends, living things will die.

Let’s look at this example of how Metabolism works within humans. It begins all with plants:
Initially, greens plants take in sunlight energy. The plants use this energy and chlorophyll, the molecule that gives plants their green color builds sugars from carbon dioxide and water.

This the process of photosynthesis, and most probably, you’ve already learned about this in an earlier biology class.

When animals and people are eating those plants (or when carnivores are eating animals that earlier already did eat those plants), they are taking in this energy (as sugar), alongside other essential chemicals that enable cell-building.

Consequently, our bodies break those sugars down and enable the released energy to be distributed to our bodies’ cells that use it as fuel.

After we’ve eaten the food, molecules in our digestive system (named enzymes) are breaking down the proteins into amino acids, the fats into s-called fatty acids, and the carbohydrates into, for example, glucose, a simple sugar. Amino acids, fatty acids, and sugar can be used by our bodies as energy sources when needed.

Then, these compounds (named ATP, or adenosine triphosphate) will be absorbed into our blood, which will carry them to our bodies’ cells. In our cells, other enzymes will regulate or speed up the chemical reactions that are involved with “metabolizing” those compounds.

Energy from those compounds may be released and used by our bodies or may be stored in our body tissue, especially in body fat, liver, or muscles.

There are many hormones of our body’s endocrine system involved in controlling the direction and the rate of Metabolism. When released, the hormone Thyroxine, for example (produced by the thyroid gland), is playing a crucial role in determining the speed or slowth of chemical reactions within the process of Metabolism within your body.

The pancreas gives hormones to help determine if our body’s metabolic activity will be catabolic or anabolic or catabolic at a given time.

Usually, our Metabolism is working well without us, giving it much of a thought. But there are times that somebody’s Metabolism could be causing some major mayhem like metabolic disorders.

Metabolic disorders are diseases that are caused by abnormal chemical reactions within our body’s cells. More lessons about Life Science are available at Covcel GED Prep.

Video Summary and Quiz

1. First, a green plant takes in energy from sunlight. The plant uses this energy and a molecule called chlorophyll (which gives plants their green color) to build sugars from water and carbon dioxide. This process is called…

Question 1 of 2

2. After food is eaten, molecules in the digestive system break proteins down into amino acids, fats into fatty acids, and carbohydrates into simple sugars. These molecules are called 

Question 2 of 2


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Last Updated on February 6, 2021.

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