You might think of proteins as a substance that is present in foods and should be included in the diet, but if studied in detail, you will find that the molecule of protein is a lot more than that. Proteins are basically made of chains of amino acids. Protein is a macro nutrient needed by the body to perform several functions like growth, cell repairing, and normal functioning of the body. Here we have discussed some of the main sources, functions, and requirements of different kinds of proteins in the body. If you wish to study more in detail about protein and other related aspects,
our private biology tutors can help you gain through understanding.
What is a protein?
Proteins are made up of long chains of amino acids linked together. When these amino acids are chained up together, that is known as peptide linkage. The number, formation and sequence of amino acids in different proteins vary. Just like we are able to construct limitless words by arranging the alphabets in different forms and are able to use them in different forms, we can make up different proteins by arranging the amino acids in variation.
What is a peptide bond?
All proteins present in the body contain different peptide chains. These chains are basically long linkages of amino acids bonded together. Whenever an amino acid forms a bond with another
amino acid, the bond formed is known as a peptide bond. In this way, when the bonding keeps on happening between one amino acid and another amino acid, a chain of amino acids is formed, and that chain is collectively known as peptide linkage. basically amino acids are building blocks of proteins. Amino acids can be reused as well from the breakdown of proteins already in body.
When two or more of these linkages are further chained together, then a polypeptide is formed. If we look at the structure of the protein in the form of insulin, it has two main peptide linkages, A and B. These two linkages from a polypeptide.
There are mainly 21 amino acids that are required by the human body and act as building blocks to function and grow properly. The body can not make all of the amino acids; some amino acids are available in the body while some amino acids are not. Among these, 12 are considered non-essential amino acids, whereas 9 are essential amino acids.
essential amino acids
There are a total of 9 essential amino acids that you must obtain from dietary sources because the human body is not capable of producing them on its own, and still, it requires them to function. These include Histidine, isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
These are not essential in a way that they are superior to other amino acids or require more. Since the body is unable to make these amino acids on its own, they are important to be taken from other sources.
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Non-essential amino acids
There are twelve amino acids which are listed as non-essential amino acids. It does not mean that these are not necessary or not required by the body. A non- essential amino acid is the one you just don't need to strictly include in your diet because our body is capable of producing these amino acids on its own. Their presence in the body is equally of great importance. These groups of amino acids include alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.
It is not that these are not required, it's just that our body can make them on its own even if we don't get these from an outer source, our body can still make these on its own.
What are the functions of proteins?
Protein is a very important macronutrient and it is involved in many functions of our body due to which we need a high protein diet. The structure and sequence of a protein determines its function and whether it is going to be used as an enzyme, hormone, or muscle mass. These are some of the main functions of a protein based on their form for example hormones and
enzyme functioning. Proteins are very high in nutritive value and are involved in many chemical processes.
Proteins as enzymes
Enzymes are proteins that help to catalyze almost all of the chemical reactions in the body. There are many different types of enzymes that react on their preferred site. Some of the major enzymes present in our body are amylase, which breaks down the complex carbohydrates into simple sugar; lipase converts fats into a form that can be utilized by the body as an energy source. Similarly, there are many other enzymes working in the body for specific purposes.
Proteins as hormones
Some hormones are made up of proteins, and these hormones are known as peptide hormones. One of the main examples of such hormones in the body is insulin. This hormone is released in the body when the blood sugar levels in the body go up. These hormones work to regulate the blood sugar levels in the body. Other peptide hormones work similarly in the body for other functions.
Oxygen Transport
Proteins are present in blood in the form of hemoglobin. Hemoglobin is made up of two main components. Iron complex (heme) and protein part connected to it (globin). It is present in the bloodstream, and it is responsible for the transport of blood from one part to other parts of the body. Many complications can occur, like anemia, if the hemoglobin is not functioning properly in the body. Red blood cells require oxygen to survive. Without oxygen, the cell will not be able to survive.
Defense through antibodies
Antibodies are proteins that are produced by the body to protect it from any foreign invasion. Whenever the body is attacked by a foreign element like a pathogen, virus, bacteria, etc., the body, in return, makes up antibodies to help it fight against those foreign elements. In this way, protein is very important for the body and serve as the protective layer that prevents it from diseases and other infections; hence the utilization of different forms of proteins is essential for the body's defense and protection.
Without these antibodies, our body wouldn't be able to protect itself from the harmful agents that might attack our body. it will always be vulnerable to outside attacks in this way.
How much protein is required by the body?
In general terms, for every kilogram of body weight, 0.8g of protein has been recommended to be taken. In this way, let's say if an adult weighs 70g, they would be advised to take in 58g of protein daily to cover their body's requirements of proteins. This amount of protein is the recommended amount and it is found as equivalent to a protein that is present in a 200g of breast piece of chicken. this is the ideal amount of protein required per day.
1gm of protein has 4gm of calories, and it is recommended that in a daily diet, there should be 10-35% of the portion allotted to proteins. if not provided for a longer time period, it can disrupt the functions of proteins in the body and eventually it can result in a deficiency or some other condition related to the deficiency of the proteins in the body.
Usually, protein deficiency is not very common in the developed countries around the world because different sources of plant and animal-based proteins are present in foods, but on the other hand, many developing countries are facing the problem of protein deficiency because people are not getting enough proteins in their diet.
What is Animal and plant-based protein?
Although there is no major difference between the two types of proteins found in animal and plants since both of them are made up of amino acids, since their origin differs and the formation of amino acids varies in the two forms, there comes a difference in their functions and utilization by the body when consumed by humans.
Both sources offer a high protein diet, but animal protein sources are known to provide the maximum amount of essential amino acids that are required by the body, and on the other hand, plant-based proteins do not fulfill the body's requirement of essential amino acids to the fullest because they lack some essential amino acids.
It is recommended to include both protein sources in the diet to get all the essential amino acids required by the body. If a person is taking in a plant-based diet only, then there are chances that they might lack some essential amino acids.
Sources of animal-based protein
There are several sources through which we can get animal-based protein in our diet, such as red meat, fish, cheese, milk, egg, and poultry. These are some of the most common sources of proteins.
Sources of plant-based protein
There are many sources through which we can obtain plant-based protein, such as tofu, lentils, peanuts, chia seeds, and almonds.
It is recommended that for the best consumption of all types of amino acids, different sources of proteins should be combined in the daily diet. For example, if you are taking an egg for animal-based protein, you can go for a handful of nuts along with it to get both types of proteins at the same time. Another example can be a Caesar salad. You can add chunks of meat to it along with different kinds of vegetables, chickpeas, and beans. The bowl alone would become a source of different kinds of proteins required by the body.
Protein deficiency
When the body is not getting enough or a variety of protein in the diet, it can lead to a condition of malnutrition in the body if prolonged.
When there is a major gap between the energy being provided to the body and the energy required by the body, it can result in a condition known as protein-energy malnutrition. Usually, this condition in children further leads to two kinds of malnutrition commonly known as kwashiorkor and marasmus. for treatment you need a high energy or high protein diet.
Kwashiorkor
It is a form of malnutrition in which the body is deprived of required protein and other forms of nutrients. This leads to severe malnutrition, and fluid starts to accumulate in the body. As a result of this, swelling starts to appear under different parts of the skin. The early symptoms include fatigue and irritability, but as the deficiency progresses, other main symptoms start to appear as well, like loss of muscle mass, swelling, and a protruded belly.
Marasmus
This is another protein and nutrient deficiency disease more commonly seen in children belonging to developing countries. In this condition, children tend to lose a hefty amount of muscle mass and start to appear immensely thin. The muscle mass and fat later start to disappear from the body in this form of malnutrition.
Why do you need to add protein to your diet?
Apart from the functions it performs once it enters the body, protein has many other benefits as well such as weight control and more energy, that make it one of the best things to be added to your diet. Here are some of the ways in which consuming protein can prove to be a very good choice for you
Healthy weight control
Protein has a very great quality of providing a feeling of fullness when consumed. Suppose you are eating a chicken sandwich or an egg. You will feel full earlier than you would feel so while eating some other food. In this way, you can feel full without eating something unhealthy. It keeps you away from eating excessive foods that can lead to unwanted and unhealthy weight gain. So if you are trying to control your weight in a healthy way, go for protein-rich foods and substitute them with junk and other unhealthy food choices. this is one of the most effective way of controlling weight.
Prevention of sarcopenia
Sarcopenia is basically a condition in which involuntary loss of muscle mass takes place. It is more common in older age. As someone grows older, this condition starts to become more apparent, and muscle loss increases. This is highly associated with less intake of proteins that is responsible for increasing muscle mass. If someone is taking in enough protein, it would be more likely that they will be able to prevent the occurrence of sarcopenia when they grow old. So to ensure your healthy old age, take in the right amount of protein from different sources.
Protein intake and athletic lifestyle
When you are leading an athletic lifestyle or adding a certain kind of exercise activity in your daily life routine, then make sure to add a bit of an excessive amount of protein to your daily life because your requirements increase more than from a person who is leading a sedentary lifestyle. you need a diet high in protein. Muscle wasting occurs when we do exercise for a longer time period, and that is recovered in a healthy way by consuming proteins in different forms. As we discussed earlier that a normal adult is required to consume 0.8g of protein per kg of their body weight. So in the situation where an adult is leading an athletic lifestyle, it would be recommended to increase their protein intake to almost 1.4g per kg of their body weight. This will help them to keep their protein requirements in check.
Can people have too much protein?
Although there aren't many supporting results to claim that having too much protein in the diet can be harmful to an individual, even if the person is taking in double the amount of protein than the RDA. still a question arises that how much protein should be taken? Since it is usually recommended that an adult should take in 0.8g per kg of their weight, and if in an increased manner they are taking double that is 1.7g per 1kg of their body weight, then it will not have much adverse effect. In the case of a disease such as kidney disease, taking in more than the required amount of protein can be a bit risky. In such cases, it is required to consult an expert who can suggest the exact amount of protein and the threshold that is safe for them to consume to ensure if they can take a diet high in protein with a lot of protein foods.
Extra protein and weight gain
Consuming extra protein or eating a lot of protein foods can lead to weight gain because the protein is not stored in the body, and the excess consumed protein is converted into body fat. That body fat leads to a gain in normal body weight. In this way, if a person is consuming protein in an amount that is more than what was required by the body, then weight gain can occur. keep a diet that has moderate amount of protein foods.
Risk of cancer
Although not all types of protein foods lead to high-risk diseases, eating some kinds of proteins in excess can prove to be harmful such as if you are only consuming protein from red meat in a greater amount, and as it has been proven to be associated with a high risk of cancer, it can lead to cancer at some point and in some cases. Usually, it is recommended that if you are consuming red meat in cooked form, make sure to not exceed the consumed amount above 350-500g in order to stay within a safer threshold and to avoid the risk of developing diseases like cancer.
Other related diseases
Recent research indicates a connection between certain types of protein sources and some diseases such as heart diseases or diabetes. Here are some of the major diseases that are being associated with different types of protein consumption
Heart disease
It has been shown by several researchers that the consumption of red meat has a direct impact on heart health. It can lead to heart attack and other cardiovascular diseases. Even if someone is not suffering from a CVD, it would still be recommended to everyone that limit the consumption of red meat for protein requirements and switch a greater part of it to other healthy sources of protein like legumes, beans, and soy in order to avoid the high risk of heart-related problems. Diets that contain lesser amounts of red meat are known to have a notable impact on the cholesterol and blood pressure levels of a person.
Eating a protein-rich diet is definitely good for heart health, but it needs to be made sure that the protein is coming from a healthy source instead of red meat only.
Diabetes
Another related disease from the consumption of red meat that arises is type 2 diabetes. Once again, it has been noted that the source of protein has a very noteworthy significance. If the protein you are consuming is coming from red meat mostly, then you are likely to develop type 2 diabetes. On the other hand, if your protein sources include more healthy ones like chickpea, legumes, lentils, etc., then the chance would be lowered.
Higher death rate
The consumption of certain types of meats such as red meat is associated with a higher death rate in individuals. According to different researches, it has been shown that people who consume protein sources more from foods like a hot dog, salami, pastrami, or simply pig meat are known to be at higher risk of early death than people who consume proteins from other sources that can be healthier food choices. So it is recommended that we make better food choices to gain protein from a healthy source in order to increase the quality of life.
Reducing environmental hazard
It has been noted that the consumption of animal-based protein can have more environmental hazards in contrast to plant-based protein. When you are consuming animal protein more than the plant-based one, you are giving rise to more greenhouse gases. Animal-based protein is known to produce greenhouse gases that pose an environmental threat to the atmospheric blanket around us. It does not mean that you have to leave the animal-based protein altogether, but it is recommended that you mix the two sources of proteins in your diet. When you are eating, make sure that you cut half or some portion of animal-based protein and add some plant-based proteins like soy, legumes, or peas with it.
Consume plant-based protein more often
Since you require a combination of both kinds of proteins, including the plant-based and the animal-based protein, you should not go for a solely plant-based approach only, but it is recommended that you should consider taking a variety of plant-based protein rather than animal-based ones. Here are some main plant-based foods that you can consider in order to switch some animal-based protein sources.
Legumes: you can pick different food items from this group to consume protein from plant-based sources such as lentils, peanuts, soy, tofu, chickpeas, lima, peas, and kidneys.
Seeds or nuts: you can get from different sources such as almonds, sesame seeds, flax seeds, sunflower seeds, walnuts, hazelnuts, almonds, and pistachio.
Whole grains: wheat, rice, millet, oats,
Conclusion
Proteins are a macronutrient and a very important part of daily life. An average adult is required to eat 0.8g of protein per kg of their body weight in their daily life routine. The quantity of protein taken in is not that important as long as it is not too low and it does not come from sources that can be risky for health. There are mainly two sources through which we can get our protiens, including animal and plant-based protein. Both of these sources should be included in the diet with equal proportions so that all types of protein are provided to the body. Some proteins should be avoided in order to ensure a healthy lifestyle. If you wish to study more about proteins and their related aspects, our private biology tutors at MTS can help you gain a better understanding.
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