The following is adapted from The Search for the Perfect Protein.

If you’ve ever heard of amino acids—which help the body make protein—you may have heard of essentialamino acids. What, exactly, makes these amino acids essential?

More importantly: why should you care about them? That’s what we’re going to unpack in this article: what essential amino acids are, how they work, and why it matters.

What Are Essential Amino Acids?

Of the 22 amino acids that the body uses to make proteins, eight of them are classified as essential. Here’s what makes them different from the other 14: we must get essential amino acids from food or supplements because our body is unable to make them.

That’s it. Pretty simple, right?

If the body has the eight essential amino acids in the proper quantities and in the right proportion, then it can make the remaining 14 non-essential acids. This is important because more than 50% of most proteins are made of these essential ones.

When the pancreatic cells get enough of the eight essential amino acids, they can make the protein insulin. You don’t have to be a diabetic to know that insulin is important.

All of the critical enzymes needed for energy, repair, detoxification, and growth are proteins made of amino acids. This allows the thyroid to make thyroid hormone, the pituitary to make growth hormone, and so—all critical for optimal health.

You’ll see arguments that there are up to ten essential amino acids, including histidine and arginine, which are required by young, growing children and the elderly.

Experiments have proven that when the eight essential amino acids are given in the right balance and quantity, the blood levels of histidine and arginine rise, proving that the body can make them, and they are not needed from an outside source.

How Amino Acids Function in the Body

Within the cell, there are two pathways for amino acids.

The first is called the anabolic pathway. Anabolic means “building up”. It’s the growth and creation of something big from something small—it is the building of proteins from amino acids. In the anabolic pathway, the amino acids that are eaten, digested, absorbed, and reached the cell are then made into a protein.

That could be a hormone, an enzyme, a neurotransmitter, or a piece of hair. This pathway takes the raw materials (amino acids) and makes them into proteins.

The other pathway is called the catabolic pathway. Catabolic means “breaking down” or “breaking apart.” It takes the complex and makes it simpler.

When the amino acid gets to the cell and it is not needed for protein synthesis, the cell will break it down into molecules of carbon, hydrogen, and oxygen—these are carbohydrates and can be used as fuel. The other molecule that results from the breakdown of an amino acid is nitrogen. This is toxic waste and must be processed by the body into urea, a protein waste product that is excreted mostly in the urine.

If this all makes your head spin, I’ve got an analogy that should help.

The Dysfunctional Car Factory

Let’s say you work in a car factory, and the minimum parts required to complete a fully functioning car are: a chassis, four wheels, a motor, and a steering wheel.

There is a mix up in the ordering of these materials, and one hundred chassis, one hundred motors, one hundred wheels, and one steering wheel arrive at the factory.

At that point, how many cars can you make at the factory? Only one. In addition, the factory has no storage space for the extra parts and you must get rid of them.

This is similar to what happens in the human body with the consumption of proteins. Each protein, whether it be from a vegetable or animal source is made up of from tens to thousands of amino acids. Many of them are not the ones that are needed by the cell at the moment they arrive. The cell has no storage depot for amino acids, and the unnecessary ones are quickly shunted down the catabolic pathway.

Since the most valuable amino acids are the essential ones, the body will take them and turn them into proteins ifthere are adequate amounts to make the given protein that the cell is working on. The amino acid supplement you take should be a mixture of the eight essential amino acids with an ideal ratio of one to another. When the ideal balance is met, nearly all the amino acids are used to make protein—that’s what our cells want!

For more advice on finding an amino acid supplement with the right blend of essential amino acids, you can find The Search for the Perfect Protein on Amazon.

For the #1 Essential Amino Acid supplement that 99% utilized by the body to create new protein look HERE.

Dr. David Minkoff is board certified in pediatrics and served as codirector of the Neonatal Intensive Care Unit at Palomar Medical Center in San Diego, California. With his wife, Sue, he cofounded LifeWorks Wellness Center in 1997, and in 2000, he cofounded BodyHealth, a nutrition company that offers a unique range of dietary supplements to the public and medical practitioners. A forty-two-time IRONMAN finisher, Dr. Minkoff is passionate about fitness and continues to train on a regular basis. He and his wife reside in Clearwater, Florida.