Profiling Protein

We have around 30,000 different proteins in our body, each versatile and unique. They all play an important role in keeping us alive!

Amino Acids

Protein has the same basic structure as carbohydrates and fats, but the difference is it also contains nitrogen. The word ‘amino’ means 'nitrogen containing', hence the name 'amino acid'. Proteins are made up of approximately 20 amino acids.

There are two types of amino acids and this is important to understand when it comes to your diet. They are called non-essential and essential.

Non-essential

As the name suggests, these amino acids are not needed to be consumed because the body naturally synthesises them. More than half of the amino acids are non-essential.

Essential

There are nine amino acids that are necessary or essential, and they need to come from our diet as the body cannot produce them on its own.

** There are amino acids that are ‘conditionally essential’ under special circumstances.

The Protein Purpose

Protein is made up of many amino acids linked together to form a variety of sequences and shapes, and this gives rise to their individual function. Protein is extremely versatile and has many purposes. Here are a few key examples:

Tissue growth and maintenance

*Protein is the foundation of muscle, blood, skin and lots of other structures in the body. For example, when building bone, a layer of the protein collagen is laid down before other minerals come into play to complete the build.

*Our skin sheds every 30 days and protein is required to replace dead and damaged cells, and is also needed for hair and nail growth.

*Exercising triggers a response from muscle cells to make new proteins to grow larger and stronger.

*Protein is also needed to replace the cells in the gastrointestinal tract every few days!

Antibodies

When a virus enters a cell, it is detected in the body as an antigen. An antibody is needed to fight off the antigen to prevent illness. Antibodies are large protein molecules which work quickly and efficiently to combat most virus’ that enter the body before they have a chance to replicate in our cells, making us sick.

Source of energy and glucose

When the body has used all carbohydrate stores, or during times of starvation, protein will be broken down to amino acids which can provide the body with energy. Although not an ideal source, amino acids can also undergo a process to produce glucose for energy, and this is called gluconeogenesis.

High Quality vs. Low Quality Protein

High quality protein contains all of the essential amino acids that the human body requires. Typically, protein found in animal products such as fish, meat, eggs, cheese, milk and yoghurt, is of high quality.

Protein found in plant products such as veggies, nuts, seeds, grains and legumes, tends to be of lower quality because it does not contain all of the essential amino acids.

Complementary Proteins

For those who do not eat meat, protein quality can be increased by mixing plant protein foods, so that together they complement each other and contain all of the essential amino acids.

Amino Acid Supplements

While consuming high quality protein shakes may be used to help stimulate muscle growth and repair, amino acid supplements will not provide any benefits to the body. They are actually more harmful than good because the body is not designed to handle high concentrations of amino acids.They can cause both toxicity and deficiency.

Unless amino acid or protein shakes/supplements have been recommended by a specialist, eating a balanced diet full of variety will be sufficient in providing the body with all of the essential amino acids to ensure protein synthesis!

Whitney, E., Rady Rolfes, S., Crowe, T., Cameron-Smith, D., Wals, A. (2011). Understanding nutrition: Australia and New Zealand edition. Melbourne: Cengage Learning, pp. 167-190.