You’ve heard about proteins. You can’t open a book about good health or the human body without coming across “proteins.”
The word comes from the Greek “proteos” which means “of prime importance,” “primary” or “first place.”
This should already clue us into their essential nature to life. Because after water and fat, proteins comprise the largest component of the human body.
Different classes of these figure into the processes of life, including:
cell integrity structure
cell growth and repair
nutrient absorption
energy production
muscle contraction
blood clotting
immune response
fluid balance
Well, you get the idea...
When you talk about “enzymes” or “hormones” or “neurotransmitters,” you’re most probably referring to some protein molecule. Or when you talk about metabolism and cellular functions, most probably, there’s some protein molecule facilitating those proceedings. Without them, the body would be a clanky orchestra playing different tunes, keys, and beats.
But, what do amino acids have to do with proteins?
Simply this: When you look closely at a protein molecule, you see that they are actually made up of amino acids.
What are Amino Acids?
There are about 500 amino acids identified in nature. Twenty of them are needed to synthesize all the different types of proteins in the body. (Some scientists include “selenocysteine” and “pyrrolysine” and therefore count 22.)
Amino acids are the building blocks of proteins. Think of amino acids as the individual beads on a necklace.
There are 20 different kinds of amino acids, and the resulting protein depends on the number and sequence of the amino acids that are linked together.
If you’ve come looking for beads in an arts & crafts store, you’ll realize very quickly that there are many different types of beads. They’re not all wooden balls with a hole in the middle. They come in different sizes, shapes, colors, and build. You can have red beads, square beads, some made of plastic, and then you also have a small, cylindrical one made of steel.
The different amino acids are like the different types of beads you find in an arts & crafts store.
What Do They Look Like?
Each amino acid has 5 parts:
1. A carbon atom at the center
2. A hydrogen atom
3. An amino group
4. A carboxyl group
5. The “Side Chain” (R)
All amino acids have the same basic structure. They are generally identical on the first 4 items on that list. They only differ on that last one: the side chain. ( “R” in the illustration.)
The side chain can be a unique mix of hydrogen, oxygen, carbon, nitrogen, or sulfur atoms. Depending on the nature and composition of the side chain, the amino acid will behave differently. That’s another way of saying that the type of amino acid and its characteristics (eg. charge or polarity) will pretty much depend on the “side chain.”
Individual amino acids link with each other to form bigger, longer, and more complex molecules.
The linking happens when the amino group of one amino acid bonds with the carboxyl group of the other. The resulting structure, as mentioned, will depend on the charge of the side chains. For example, if one is + and the other is –, they will “fold” towards each other. If they are both positive or both negative, then they will “fold” away from each other.
When you have a chain of 2 to 50 amino acids, this segment is often called a peptide. Peptides comprise the proteins which can be 50-2000 amino acids long.
What are the Different Kinds of Amino Acids?
Essential Amino Acids
Of the 20 different amino acids, 9 of them are considered “essential” amino acids. The body cannot produce these items, so we get our supply of them from our diet.
We get essential amino acids in protein-rich foods like meat, eggs, milk, fish, seeds, and nuts.
The essential nine are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
Histidine—is used to produce histamine, a neurotransmitter working for the immune system. It also helps regulate the sleep-wake cycles.
Isoleucine—helps produce hemoglobin and regulate energy. It is mostly found in the muscles and is involved in muscle metabolism.
Leucine—helps regulate blood sugar levels and promote wound healing and muscle repair.
Lysine—helps produce collagen and elastin, vital ingredients for young, healthy skin.
Methionine—plays a vital role in removing toxins from the body and facilitates the absorption of minerals zinc and selenium.
Phenylalanine—is a precursor for melanin, dopamine, and norepinephrine, all playing significant roles in the body.
Threonine—plays a role in metabolizing fat, in addition to helping produce collagen and elastin.
Tryptophan—is a precursor for serotonin, a regulator of appetite, mood, and sleep.
Valine—is involved in energy production and muscle growth and repair.
Non-essential Amino Acids
There are 11 non-essential amino acids. These are alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine. Calling them “non-essential” is really a misnomer because they perform essential and critical functions in the body.
Alanine—not only helps regulate cholesterol levels but also helps remove toxins from the body.
Arginine—helps regulate blood pressure by helping the blood vessels relax, improving circulation.
Asparagine—is vital to the normal functioning of the brain, facilitating the production of certain neurotransmitters.
Aspartic acid—plays a role in energy production and has been used to treat chronic fatigue.
Cysteine—is vital in collagen production and found in beta-keratin, the protein in hair, skin and nails.
Glutamic acid—performs an important role in digestion by metabolizing sugars and fat.
Glutamine—is the most abundant amino acid in the blood and also has the most versatile functions, from regulating metabolism to kidney health, and immunity.
Glycine—helps produce the powerful antioxidant glutathione. It’s also known to help protect the liver from alcohol-induced damage.
Proline—helps in protein synthesis. In addition, it’s also been found to protect against wrinkles and aid healing of the skin.
Serine—is a precursor to glycine and cysteine and plays a vital role in the biosynthesis of purines and pyrimidines.
Tyrosine—is an essential component of dopamine, norepinephrine, and epinephrine, critical neurotransmitters in the brain.
The Magic of Protein Synthesis
We often meet “proteins” in the context of nutrition, and talk about it alongside sugar and carbohydrates, debating how much of it we should incorporate into our diet should we want to lose weight. But proteins and, by extension, amino acids, are so much more than that.
A specific chain of amino acids will practically dictate how healthy you are or how your eyes will look like.
How?
Through a process called “protein synthesis.” That’s when you build proteins according to a very specific sequence of amino acids.
So you ask, “How does the body know how to arrange the amino acids to form proteins?”
Well, it follows a set of instructions, and that set of instructions is kept in the DNA.
The DNA, which has all the genetic codes, is found inside the nucleus of the cell. (The DNA is too big to pass through the walls of the nucleus.)
Protein synthesis actually happens in the cytoplasm, outside the nucleus, so how does the DNA direct the production of proteins?
A “transcribing” process happens. A “messenger” RNA, small enough to pass through the nuclear membrane, takes the information from the DNA and transports it outside to the cytoplasm. It then looks to a protein factory called the ribosome. The ribosome reads the information and starts building the protein piece by piece. (This is an oversimplified picture of what is a complex process.)
When a full chain of protein is finished, it will be responsible for one (or more) of the thousand functions in the body—from metabolism to immunity, to even the color of your eyes.
How?
The color of your eyes is based on the pigment that is inside the eyes. A protein is responsible to produce that specific color pigment! (And that protein was constructed based on the instructions from the DNA inside the nucleus!)
The human body is such a wonder. Through a series of amino acids, proteins, responsible for practically every biological function, keep us healthy and alive.
Bloodworks Lab, as a premier medical testing agency in the Philippines, can give you a behind-the-scenes look into the workings of your body. We are a one-stop shop for all your blood test needs. We also offer a battery of screening and immunological tests.
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