What is protein?

What is a Protein? Understanding this Essential Biomolecule.

Proteins are the real unsung heroes of our bodies. They play a crucial role in almost every aspect of our biology. But what exactly is a protein? Let's dive into the fascinating world of proteins to find out.

What is protein ? Protein structure.

Primary structure.

Amino acids are the building blocks of proteins. Imagine them like pearls on a necklace.

Secondary structure.

Here, the "necklaces" of amino acids begin to fold into more complex structures like α-helices and β-sheets.

Tertiary and Quaternary structure.

This is the level where the magic happens. Proteins fold into 3D structures that allow them to function.

AminoAcids, Basic Components of Proteins.

What is protein?

What is an Amino Acid ?

Amino acids are the basic building blocks of proteins. Imagine them like pearls on a necklace, where each pearl represents a different amino acid. When linked together in a specific sequence, they form a protein. There are 20 different types of amino acids that can be combined to create a protein. Each amino acid has its own properties and functions, giving each protein its unique structure and function.

Protein functions: the Architects of Our Biology.

Catalysts of Metabolic Reactions.

Enzymes are proteins that act as catalysts in our bodies, speeding up the chemical reactions necessary for life. Imagine for a moment a factory where thousands of chemical reactions take place every second. Without enzymes, these reactions would be so slow that life would be impossible. For example, digesting food would be an extremely slow process without the action of digestive enzymes such as amylase and lipase. These enzymes break down carbohydrates and lipids into smaller molecules that our bodies can use for energy and cellular repair. In short, enzymes are the master craftsmen of our metabolism, orchestrating a complex symphony of chemical reactions that keep us alive.

Nutrient transport.

Hemoglobin is another essential protein that acts as a "taxi" for oxygen molecules in our body. Located in red blood cells, haemoglobin binds to oxygen molecules in the lungs and transports them through the circulatory system to the tissues that need them. Without haemoglobin, oxygen would not be able to reach our cells, leading to the failure of many bodily systems. But the role of proteins in transport doesn't stop there. Other proteins, such as transferrin, transport iron, while albumin transports various small molecules, including hormones, fatty acids and drugs. These transport proteins ensure that nutrients and essential molecules reach their destination, allowing our bodies to function optimally.

Regulation of Cellular Processes.

What is protein?

Hormones are chemical messengers that regulate various vital processes in our bodies, and many of them are proteins. Take insulin, for example, a protein hormone produced by the pancreas. Insulin regulates glucose levels in the blood by facilitating its absorption by the cells. An imbalance in insulin levels can lead to serious conditions such as diabetes. Similarly, other protein hormones such as leptin regulate appetite, while adrenaline, although not a protein, interacts with protein receptors to prepare our bodies for 'fight or flight' situations. These hormones act like conductors, directing cells and organs to work in harmony. Without these regulators, our bodies would be out of balance, which could lead to a host of health problems

Muscle Building and Recovery.

  • Protein plays a vital role in building and repairing muscle tissue. When you train, particularly during resistance exercise such as weight training, micro-tears occur in the muscle fibres. That's where proteins come in. Amino acids, which are the basic building blocks of protein, are used to repair these micro-tears, leading to increased muscle growth.

  • But that's not all. Proteins are also involved in the production of new muscle fibres, a process known as muscle hypertrophy. Hormones such as testosterone, which interact with protein receptors in muscle cells, can stimulate this process. This is why adequate protein intake is essential for anyone looking to gain muscle mass or improve athletic performance.
  • In addition, protein contributes to muscle recovery by helping to reduce muscle damage and speed up tissue repair. This is particularly important for athletes or anyone engaged in intense physical activity. In short, if you're looking to get stronger, faster or simply fitter, protein is your go-to ally.

The Caloric role of Proteins: Energy and Metabolism.

Food thermogenesis.

One of the most interesting aspects of protein is its effect on dietary thermogenesis, i.e. the amount of energy needed to digest, absorb and use nutrients. Proteins have a higher rate of dietary thermogenesis than carbohydrates and fats, which means that your body uses more energy to metabolise them. This can contribute to weight loss by slightly increasing your metabolism.

Calorie balance.

Protein contains around 4 calories per gram, which is similar to carbohydrates but much less than fat, which contains 9 calories per gram. However, because of their effect on satiety and thermogenesis, proteins may be more effective for weight control.

Energy for Exercise.

Protein isn't usually a primary source of energy during exercise, especially if you're consuming enough carbohydrates. However, during prolonged exercise or if you are carbohydrate deficient, protein can be broken down to provide energy.

Examples of Important Proteins: The Superstars of Our Biology


Insulin is a protein hormone produced by the pancreas, and it plays a vital role in regulating carbohydrate metabolism. Without it, our cells would not be able to absorb sugar properly, leading to high levels of glucose in the blood. This imbalance can lead to serious conditions such as type 1 or type 2 diabetes. Insulin acts like a key, opening doors in cells to allow glucose in, which is then used as an energy source or stored for future use.


Collagen is the most abundant protein in our bodies, making up around 30% of all body proteins. It is essential for the health of our skin, hair, nails and joints. Collagen gives our skin its elasticity and helps skin cells regenerate. It is also crucial to joint health, as it acts as a 'lubricant', allowing fluid movement and reducing wear and tear. Without enough collagen, we could suffer from skin and joint problems, including premature wrinkles and arthritis.


Actin is a globular protein that forms actin filaments, an essential component of the cytoskeleton in all eukaryotic cells. In muscle cells, actin interacts with another protein called myosin to enable muscle contraction. This interaction is at the heart of every movement we make, from lifting a dumbbell to walking and even the beating of our heart. Without actin, our ability to move, speak and perform almost any physical activity would be severely compromised.

Importance of Proteins in the Diet: The Fuel of Life.

A Universal Need.

Proteins are essential in our diet, whether we are vegetarians, vegans or omnivores. They are often called the "building blocks of life" because they are crucial for almost every biological function, from cell repair to hormone regulation. Without a sufficient supply of proteins, our bodies would not be able to function properly.

What is a protein ?

Source of Essential Amino Acids.

Protein is made up of amino acids, 9 of which are considered "essential". These amino acids cannot be produced by our bodies and must therefore be obtained through our diet. Animal protein sources such as meat, eggs and dairy products generally contain all the essential amino acids, whereas plant sources may be lacking. It is therefore important for vegetarians and vegans to combine different plant protein sources to obtain a complete amino acid profile.

Protein, Muscle Building and Recovery.

As mentioned above, protein is vital for building and repairing muscle tissue. This is particularly important for athletes or anyone engaged in intense physical activity. Adequate protein intake can help speed recovery, reduce muscle soreness and improve sports performance.

Importance for Overall Health: More than Just Muscle.

Beyond their role in building muscle, proteins are a pillar of our overall well-being, influencing everything from bodily functions to athletic performance. They are essential for the production of enzymes, hormones and neurotransmitters, which regulate everything from our metabolism to our mood.

Weight control.

Proteins are also essential for weight control. They help to increase satiety, reducing snack cravings and contributing to a lower calorie intake. What's more, protein metabolism requires more energy, which helps burn more calories.

Athletic performance.

For athletes and active people, adequate protein intake is crucial for optimising performance. They not only promote muscle recovery but also endurance, enabling longer, more intense workouts.

A lack of protein can lead to a multitude of health problems, including loss of muscle mass, immune problems and growth disorders in children.

Food sources.

You can get protein from a variety of sources, each with its own advantages and disadvantages.

  • Meat: Meats such as chicken, beef and pork are excellent sources of complete protein, containing all the essential amino acids. They are also rich in vitamins such as iron and vitamin B12.
  • Fish: Oily fish such as salmon and mackerel are not only rich in protein, but also in omega-3 fatty acids, which are beneficial for heart health.
  • Eggs: Considered the most complete source of protein, eggs are also rich in vitamins and minerals.
  • Dairy products: Milk, yoghurt and cheese are good sources of protein and also contain calcium and vitamin D.
  • Pulses: Lentils, chickpeas and beans are excellent sources of protein for vegetarians and vegans.
  • Vegetables: Certain vegetables such as broccoli, spinach and asparagus contain surprising amounts of protein and are also rich in fibre and antioxidants.

Protein supplements.

If you have specific protein requirements, perhaps due to sporting goals or dietary restrictions, protein supplements can be a great option.

  • Protein Shakes: These drinks are convenient, especially when you're on the go or don't have time to prepare a full meal. They come in a variety of flavours and types, including whey protein, casein, and plants like pea and hemp.
  • Protein Bars: These are also a convenient option and can be eaten as a snack or even as a meal replacement when needed.
  • Protein Powders: These powders can be added to smoothies, yoghurts or even cooking recipes to boost the protein content.

Coach's advice.

What is protein?
  • Excess Protein No, eating too much protein isn't dangerous for most people, unless you have a specific medical condition..
  • Factors to Consider Your protein needs depend on a number of factors: your age, your activity level, your sporting goals and even your lifestyle.
  • How QNT Can Help: At QNT, we have a full range of protein products to help you become the best version of yourself. Whether you're a vegetarian, a top athlete or just someone who wants to improve their health, we've got you covered; Whey proteins, Whey protein isolates, casein.

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