Glycine Structure, Properties, and its Benefits

Glycine Structure

An integral component of vital biological molecules, glycine is one of the simplest amino acids. It is a central component of several metabolic reactions. Glycine has various crucial roles, such as acting as a neurotransmitter inhibitor in the brainstem and spinal cord. It is also an immune-modulating agent.

Learn in detail about glycine structure to understand its properties and benefits.

Glycine: A Non-Essential Amino Acid

There are 20 amino acids. Nine of these are essential amino acids, while the rest are non-essential amino acids. Glycine is one of the non-essential amino acids.

Before learning more about glycine, it is important to understand the difference between essential and non-essential amino acids.

Essential Amino Acids: The amino acids that the body cannot synthesize. They must be taken via food supplements. The nine essential amino acids are as follows:

1. Leucine
2. Tryptophan
3. Histidine
4. Lysine
5. Isoleucine
6. Threonine
7. Methionine
8. Phenylalanine
9. Valine

Non-Essential Amino Acids: The ones that are synthesized by our bodies. It is not necessary to take them via food supplements. The 11 non-essential amino acids are as follows:

1. Arginine
2. Glycine
3. Alanine
4. Asparagine
5. Cysteine
6. Glutamine
7. Aspartic acid
8. Glutamic acid
9. Proline
10. Serine
11. Tyrosine

Additionally, one more category.

Conditional Amino Acids: The amino acids that are not usually essential but may become essential in times of illness/stress. The conditional amino acids include

1. Cysteine
2. Tyrosine
3. Arginine
4. Glutamine
5. Ornithine
6. Glycine
7. Serine
8. Proline

Glycine Formula

The glycine formula is NH₂‐CH_₂‐COOH. Its IUPAC name is 2-Aminoethanoic acid. Glycine is abbreviated as G or Gly.

Glycine Formula

Glycine Structural Formula

The glycine structural formula shows its two carbon atoms, five atoms of hydrogen, one nitrogen atom, and two atoms of oxygen.

Like all other amino acids, the backbone consists of an amine group (−NH₂) bound to a central carbon and a carboxyl group. The carboxyl group contains carbon that is double bonded to oxygen and single bonded to a hydroxyl group (-OH).

The glycine structure is the simplest of all human amino acids. Its side chain has just a single hydrogen atom. Its central carbon is achiral. The following diagram depicts the glycine structural formula.

Structural Formula of Glycine

Glycine Lewis Structure

Now that you know the structural formula of glycine, let us explore the distribution of electrons in the molecule.

The glycine lewis structure shows valence electrons. The nonbonding electrons are shown as dots, and the bonding electrons are lines between atoms.

Glycine has ten pairs of bonding electrons and five pairs of nonbonding electrons (lone pairs). Thus, it has 20 bonding electrons and 10 nonbonding electrons.

Glycine Lewis Structure

Formation of Glycine

Glycine is formed from serine. Serine is made from 3-phosphoglycerate (3-PG), an intermediate in the cellular respiration process- Glycolysis.

So, the series of steps in the formation of glycine are as follows:

• Conversion of glucose into 3-PG via glycolysis or 3-PG formation on the breakdown of glutamine
• The action of the enzyme 3-phosphoglycerate dehydrogenase to convert 3- into 3-phosphooxypyruvate.
• 3-phosphooxypyruvate conversion to phosphoserine when acted upon by the enzyme phosphoserine aminotransferase.
• Phosphoserine turns serine when the enzyme phosphoserine phosphatase acts on it.
• The enzyme serine hydroxymethyltransferase transforms serine into glycine.

Properties of Glycine

Following are some characteristic features of glycine:

• It is nonpolar.
• Hydrophobic but can exist in hydrophilic conditions owing to its small size.
• A white crystalline solid.
• It has a sweet taste.
• Acts as a buffer solution at six pH due to its acidic nature

Uses of Glycine

Glycine finds its usage in a wide range of health benefits, including:

• It is effective in the treatment of stroke, benign prostatic hyperplasia, schizophrenia, and some other inherited metabolic disorders.
• As a sweetener or a taste enhancer
• Some drugs containing glycine help improve gastric absorption.
• It is also used as a buffering agent in analgesics, antiperspirants, antacids, cosmetics, toiletries, and more.
• It acts as an intermediate in manufacturing herbicide glyphosate.
• It is used as a supplement as it is a building block for collagen, a protein found in ligaments, muscles, and bone connective tissues. It is a contributor to 33% of the collagen in the human body.
• People use glycine to support leg ulcers and liver damage.
• The CNS, or the central nervous system, including the brain and the spinal cord, are affected by glycine concentrations.
• Glycine also binds to toxins so that the body can clear them.

Diseases Related To Glycine

Glycine encephalopathy is the name of a disease characterized by very high levels of the amino acid glycine. It is an inherited metabolic disease, and the inheritance type is autosomal recessive.

Usually, glycine serves as a chemical messenger for transmitting signals in the brain. The most common form of the disease is the classical neonatal form. The symptoms appear within a few days of life, including:

• Lack of energy
• Weak muscle tone
• Hiccups
• Seizures
• Breathing problems

The disease affects one in 60,000 people. It is the second most common amino acid-related disease after phenylketonuria.

Another glycine-related disease is nonketotic hyperglycinemia. This disorder has abnormally high levels of glycine in the body. The condition is termed hyperglycinemia. The extra glycine builds up in organs and tissues, especially the brain, and the patient suffers from serious neurological problems.

Benefits of Glycine

Some key benefits of glycine are mentioned below:

• It is required to produce the powerful antioxidant –glutathione. This antioxidant protects cells against oxidative damage by free radicals. Lesser glycine in the body means less glutathione, and this condition would negatively impact how your body handles oxidative stress.
• The body uses glycine to make creatine that provides energy to muscles for performing quick and short bursts of activity like weightlifting.
• It can improve sleep quality in people who struggle to get a good night’s sleep. Glycine has a calming effect on the brain and thus helps fall and stay asleep. It lowers the core body temperature, which promotes sound sleep.
• It can protect the liver from alcohol-induced damage. It prevents inflammation.
• Increasing evidence favors the theory that glycine offers support against heart disease. It helps prevent the accumulation of compounds linked to atherosclerosis.
• It can help people with Type 2 diabetes. Type 2 diabetes brings down glycine levels in the body. So, taking glycine can improve impaired insulin response in diabetics.
• It can reduce muscle wasting in aging and malnutrition conditions.

Role of Glycine Supplements

In addition to the glycine produced in the body, you can take glycine supplements. Glycine supplements have proved their potential in the following fields:

• Glycine stimulates serotonin production, the hormone that elevates mood and improves memory and thinking.
• Glycine supplements improve sleep in people with insomnia.
• It also improves fatigue feelings and improves performance.
• It can help treat schizophrenia, a mental illness that results in delusions and unusual behavior.
• Healthcare providers also prescribe glycine to treat ischemic stroke.
• Its anti-inflammatory and antioxidative properties help reduce heart disease risk.

What Are the Side Effects of Glycine?

Consuming a glycine supplement may have some side effects. Although they are generally safe if you take them as per the directions, research suggests some possible side effects, including gastrointestinal symptoms like

• Upset stomach
• Nausea
• Vomiting
• Diarrhea

What Glycine Dosage is Safe?

You must always consult a healthcare provider before opting for any supplement. Your doctor will prescribe the appropriate glycine supplement dosage for your individual needs.

Glycine comes in different formulations. Commonly, oral gel caps are available in 500 milligrams to 1,000 mg. You can also add powdered formulations to your shakes or smoothies.

What happens if you take too much glycine?

Although glycine toxicity is rare, it can occur when used with sterile water, usually after prostate or bladder surgery. Signs of glycine overdose are as follows:

• Visual disturbances
• Drowsiness
• Weakness
• Vomiting
• Prickling skin sensations
• Skin flushing

Food Sources Containing Glycine

You can easily find glycine in high-protein foods such as:

• Legumes
• Fish
• Dairy
• Seeds
• Chicken
• Peanuts
• Canned salmon
• Granola
• Hard Cheese
• Quinoa
• Pasta
• Soybeans
• Bread
• Eggs
• Almonds

Conclusion

Glycine is an amino acid synthesized in our body. It promotes the building of collagen, clears toxins from the body, and transmits nerve impulses. The glycine structure contains two carbon atoms, five atoms of hydrogen, one nitrogen atom, and two atoms of oxygen. It is an amino acid with the simplest structure because it has only a hydrogen atom attached to its side chain. Consuming foods rich in glycine can help boost your immune system and various bodily functions.

Frequently Asked Questions

Q1. What is the function of glycine?

In the central nervous system, the amino acid glycine is responsible for its neurotransmitting function. It plays many roles in peripheral and nervous tissues. It also serves as an antioxidant and anti-inflammatory substance. Glycine is cryoprotective. It helps boost memory and sleep.

Q2. Is glycine a weak acid?

Glycine is hydrophobic and nonpolar in nature. It is neither a strong acid nor a strong base. 0.1 M glycine has a pH of 2.2.

Q3. Why is glycine also called a conditionally essential amino acid?

Certain amino acids are usually not essential, but they become essential in case of an illness or stress. Glycine is one of those amino acids, and hence it is named conditional amino acid. It can be required in conditions like prematurity in infants. So, glycine becomes an essential amino acid under certain conditions only, and generally, it is a non-essential amino acid.