The importance of protein can not be overemphasized as they are primary sources of essential nutrients (amino acids). Hence, health practitioners and nutrition specialists’ continuous exertions on the importance of incorporating available protein sources in our meals as often as possible.

What’s a balanced diet without the inclusion of protein-laid food? The amount of protein we need as humans depend on our age and sex. What is protein, and why is there so much fuss about its composition?

What is protein?


Protein is a macronutrient. It is known to be one of the three major nutrients found in our food, one which the body needs in a large amount. It is vital for the building and maintenance of body muscle and tissues.

They are made of small compounds known as amino acids. Hundreds of these amino acids exist in nature, though the human body only needs 22 of them. The human body can also produce all but nine it requires to function correctly. These nine in question are referred to as the essential amino acid. Again, they must come from the food we eat. These foods contain different combos of amino acids. Generally speaking, animal proteins such as dairy, eggs, and dairy contain all essential amino acids. 

What proteins are made of – all you need to know.

Proteins are commonly made from different amino acids that are linked together. The body uses twenty amino acids to create proteins, and they are:

  1. Methionine
  2. Alanine
  3. Lysine
  4. Arginine
  5. Asparagine
  6. Leucine
  7. Aspartic acid
  8. Isoleucine
  9. Cysteine
  10. Histidine
  11. Glumatic acid
  12. Glycine
  13. Glutamine
  14. Valine
  15. Phenylalanine
  16. Tyrosine
  17. Serine
  18. Tryptophan
  19. Threonine
  20. Proline

Protein is made up of three hundred or more amino acids. The actual amount of amino acids and their sequence are all unique to the different proteins. One could also arrange the letters in the amino acids millions of ways to other words and create an entire protein language. The protein which results from the number and sequence of amino acids will determine its shape. The shape formed from the process is vital as it ends up determining its (the protein’s) function (examples are enzyme or muscle).

Every living organism on earth (including humans) has a unique characteristic protein. These amino acids are classified as essential or non-essential amino acids. Just as the name implies, while essential amino acids can’t be produced by one’s body (it has to come from what we eat), the non-essential amino acid, on the other hand, can be made by our body and as a result, it doesn’t need to come from what we eat.

Proteins can either be complete or incomplete. Complete proteins refer to proteins with essential amino acids. Soy, quinoa, and animal products are all complete proteins.

Incomplete proteins, on the other hand, are proteins that do not contain the essential amino acids. Many plant foods are categorized as incomplete proteins, including grains, beans, and nuts.

You can combine incomplete protein food sources to create a meal that will provide you with essential amino acids. Examples include whole-wheat bread with peanut butter or rice and beans. 

The difference between animal-based protein and plant-based protein


Without a doubt, both plant- and animal-based protein are a rich source of protein. But the question is, do they have similar qualities? The quality of protein can be classified in different ways, but these classifications still relate to the proportion and distribution of both the essential and non-essential amino acids.

Animal-based proteins are rich and of high quality, as they are known to contain a very high proportion of essential amino acids in comparison to plant-based proteins.

There is this growing misconception about plant-based proteins and how it lacks essential amino acids. Contrary to that school of thought, most plant-based proteins contain the entire twenty amino acids though they tend to have a limited volume of some essential amino acids.

This means that when a small number of plant foods are taken as the only protein source, they won’t supply you with enough essential amino acids.

Functions of protein

So, what is the primary function of a protein? Let’s share with you some of the parts of the protein.

  1. Antibodies

Proteins are known to form antibodies that are responsible for fighting off illness, infections, and diseases. They identify and also assist in warding off antigens such as viruses and bacteria.

  1. Provides energy

It’s probably one of the many things you were taught in school about protein – that it’s a significant source of protein. When we consume excess proteins (more protein than our body needs) to maintain bodily function, including tissue maintenance, it uses it as fuel for energy.

  1. Transportation of molecules

Asides from providing energy and forming antibodies, proteins can also transport and store molecules. For instance, hemoglobin (a type of protein) is responsible for transporting oxygen throughout the body. That’s not all; proteins can also store some types of molecules – ferritin is one such unique protein. The ferritin helps with storage in the liver.

  1. Repair & maintenance

It will be impossible to repair and maintain body tissues when one lacks a healthy amount of protein. One of the protein’s functionalities is to help improve tissues, including repair and development. Eyes, skin, hair, organs, and muscles are formed from protein.

In summary, protein acts as the building block of the body. It doesn’t just build & maintain body tissues. To break it down further, someone who’s got injuries breaks down muscle during workout sessions or has undergone surgery needs an increased amount of protein.

How much protein do we need?

The Food and Drug Administration (FDA) recommends that adults take fifty grams of protein daily, part of a two thousand calorie diet. Your daily value may be lower or higher. It all depends on the calorie intake. According to the dietary guideline they published online (from 2015 to 2020), categorized by sex and age:

Age (years)Protein RDA (grams)
1 – 313 g
4 – 819 g
9 – 1334 g
 14 – 18 (female teen)46 g
14 – 18 (male teen)52 g
19+ (female adult)46 g
19+ (male adult)56 g

Many factors can affect the volume of protein you need, including your weight, activity level, whether or not you are pregnant, and your height. Other factors include the digestibility of the different amino acids and the proportion of the individual amino acids.

Protein deficiency

Only a few nutrients are as vital as protein. Most of the food you eat right now contain some protein. Thus, true protein deficiency is quite rare, though, mostly in developed countries. But some people will always be at risk. Protein deficiency, just as with any other defect, leads to different health problems. Low protein intake is a cause for concern, as it’s known to cause slight changes in the body with time.

  • What is protein deficiency?

It is when the food you eat is unable to meet the body’s required nutrients adequately. Over a billion people from around the world suffer from protein deficiency. The problem is quite severe in the third-world region like in South Asia and Central Africa, where more than thirty percent of their population get little or no protein from their meal.

  • Some symptoms of protein deficiency
  • Hair, Nail, and Skin Problems

Protein deficiency often shows on the human skin, the hair, and the nails, mostly made of protein. Faded hair color, hair thinning, brittle nails, and hair result from protein deficiency.

  • Edema 

Edema is characterized by puffy skin, a classic symptom of kwashiorkor. Scientists also believe it results from human serum albumin, the most abundant protein in the blood plasm. One of its primary functions is to help maintain oncotic pressure – a force that’s known to draw fluid into the blood as it circulates. This way, albumin prevents excessive amounts of fluid from accumulating in tissues or any other body part.

  • Fatty liver 

Fatty liver is one other symptom of kwashiorkor, and it can also be referred to as fat accumulation on one’s liver cells. When left untreated, this condition may morph into fatty liver disease, which then causes inflammation, liver scarring, and liver failure. Fatty liver is one common condition that occurs in people who are obese and those who take alcohol a lot.

Even though this condition occurs in protein deficiency cases, studies suggest that impaired synthesis of proteins known to transport fats may contribute to the contribution.

  • Muscle mass starts to reduce

Our muscles are our bodies’ largest reservoir of protein. If (and when) dietary protein is not adequately supplied, the body may take protein from skeletal muscles to help preserve bodily functions and most vital tissues. Lack of protein causes loss of muscle mass over time.

Moderate protein is also not enough, as it could also lead to loss of muscle mass, though mostly in older adults.

  • Stunted growth (mainly in children)

Protein doesn’t just help maintain bone or muscle mass; it is also essential for overall body growth. Protein deficiency or insufficient is harmful to children whose developing bodies need a steady supply. Stunting is a common sign of childhood malnutrition. Back in 2013, over one-sixty million children suffered from stunted growth. Stunted growth is one of the known long-term symptoms of kwashiorkor in children.

Food sources of protein

where are proteins found? In lots of foods, you are probably eating one right now! Anyways, here are some food sources of protein:

  1. Eggs
  2. Almonds
  3. Chicken breast
  4. Cottage cheese
  5. Oats
  6. Greek yogurt
  7. Milk
  8. Broccoli
  9. Lean beef
  10. Pumpkin seeds
  11. Quinoa
  12. Tuna
  13. Whey protein supplements
  14. Turkey breast
  15. Shrimp
  16. Ezekiel bread (Spouted bread)
  17. Lentils
  18. Fish
  19. Peanuts
  20. Brussels sprouts

Fruits sources of protein

There are tons of fruits with protein, and we’ll be sharing some of them with you.

  1. Prunes: the powerhouse of cancer-fighting fiber and antioxidants
  2. Peaches: A rich source of beta-carotene, one which helps in boosting your eyesight and immunity.
  3. Cantaloupe: relatively rare, cantaloupe is a fantastic melon. It is rich in vitamins A, B, K, and of course, minerals too. A cup of cantaloupe contains 0.8 to 1.5 grams of protein. A versatile fruit, the seeds are also packed with powerful health benefits that can be added to both smoothies and salad.
  4. Oranges: 100 g of it serves up about 0.9g of protein. This means, on average, oranges can supply you with 2 g (approximately) of protein.
  5. Kiwi: Asides from delivery of an ideal dose of protein, this fruit has lots of other healthy perks, most of which you are not aware of right now.
  6. Cherries:  It isn’t the most popular fruit on this list. However, most times, we don’t eat fruits (and food in general) for their taste, but their health benefits and cherries are no exception. Dried cherries are one of the top protein-rich fruits.
  7. Figs: Quite similar to oranges, you’ll find 0.8 grams of protein in every 100 grams of figs. It’s safe to say figs are protein-rich fruits. They contain sugar in high concentration and a great source of fiber.
  8. Blackberries: These fruits are among the healthiest foods on earth. A cup contains two grams of protein and 7.6 grams of fiber, and many vitamins and minerals. Berries also contain antioxidants such as anthocyanins, vitamins c, magnesium, iron, calcium, vitamin A, E, and K. 
  9. Jackfruit: jackfruit is found to be rich in proteins – not just that, they also contain a significant amount of dietary fiber, vitamins A, C, and lots of other antioxidants.

Building Blocks of Protein

What are the building blocks of proteins? Even though the twenty amino acids are unique, the basic block follows the same pattern. The entire amino acids contain carbon atom which lies right in the core of the molecule, surrounded by three different chemical groups. Also, two out of these chemicals, an amino group and a carboxyl group, are the same in the amino acids.

However, the third group differentiates each amino acid. The R-groups can be quite simple, similar to the hydrogen atom, just as in the amino acid glycine. But it could be as complicated as the structure found in tryptophan that has double rings.


The bottom line is that protein has tons of body roles, from repairing and building the body’s tissues to allowing metabolic reactions to coordinate our bodily responses. Protein doesn’t just provide the body with a well-structured framework; they also maintain the right fluid and pH balance.

Finally, they keep our immune system consistently healthy, transport, and store nutrients that can act as fuel for energy. You not only read about the sources of protein, the function,s, and building blocks. So, what do you think? Could you share your thoughts with us here?

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