Table of ContentsView AllTable of ContentsWhat It IsHow It WorksTypes and UsesDietary SourcesHow to Get Enough in Your DietProtein Deficiency
Table of ContentsView All
View All
Table of Contents
What It Is
How It Works
Types and Uses
Dietary Sources
How to Get Enough in Your Diet
Protein Deficiency
A protein is a large, complex molecule that is a key building block of life. We all know that it is an important part of our diets, but how many of us knowhow protein actually worksin our bodies, and why we need it?
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Protein is vital to the functioning of cells in living organisms.Proteins are required for the structure and regulation of the body’s tissues and organs. They are made up of long chains of amino acids—at least 20 different types of amino acids, in fact.
Nine of the amino acids that people need for making protein—histidine, isoleucine,leucine,lysine,methionine, phenylalanine, threonine, tryptophan, andvaline—must come from food.
Complete vs. Incomplete Proteins: Understanding the Difference
A protein begins in the cell as a long chain of about 300 building blocks (on average) known as amino acids. There are more than 20 different types of amino acids, and how they are ordered determines how the protein chain will fold upon itself and take shape.
Once a protein has its shape, it can bind to other selected molecules in order to carry out its function.That function could be signaling, storing, transporting, providing structure, fighting foreign invaders, acting as a catalyst, or another function.
Types of Protein and Their Uses
Proteins come in a variety of types, according to function. These include the following:
Antibody
These are components of the immune system that help to protect the body from foreign particles, such as viruses and bacteria. Proteins recognize and bind themselves to foreign substances in order to neutralize them and help protect the body. An example is of an antibody is immunoglobulin G (IgG).
The 5 Types of Antibodies
Enzyme
An example of an enzyme isphenylalanine hydroxylase. This enzyme catalyzes the breakdown of the amino acid phenylalanine. Infants born unable to make this enzyme have toxic effects from the incomplete metabolism of phenylalanine.
Messenger
Also known as signaling proteins, they allow communication between cells. They include some types of hormones. These proteins transmit signals to coordinate biological processes between cells, tissues, and organs. An example of a messenger protein is somatotropin, also known as growth hormone.
Structural
Structural proteins allow cells to maintain their shape and organization. On a larger level, they provide the structural elements of connective tissues such as bone andcartilageand help muscles to function. An example of a structural protein is actin.
Transport and Storage
Incomplete Protein: Important Nutritional Value or Not a Concern?
How Much You Need
You likely won’t have problems getting enough protein. According to an analysis published inPublic Health Nutrition, people in the U.S. consume more protein than is needed each day.
The study found that men ages 20 and above take in 234 grams (8.3 ounces) of protein per day (from sources including meat, dairy, fish, seafood, eggs, nuts, legumes, and soy), 72% coming from meat; while women take in 148 grams (5.2 ounces) of protein daily, with 70% from meat.
Since protein is integral to the function of every cell in your body, it’s important to get enough of the macronutrient in your diet—from healthy sources. Getting your protein from diverse sources, including ones that are plant-based, will give you the healthiest balance.
The protein food group includes meat, poultry, seafood, legumes (beans, peas, and soy products), eggs, nuts, and seeds. The USDA recommends opting for leaner, less fatty meat and poultry items, as well as consuming at least 8 ounces of cooked seafood per week if you are not a vegetarian.
What Foods Are High in Protein?
Protein deficiencies are rare for people in wealthier countries, such as the United States. Even vegetarians and vegans typically take in more than the daily recommended amount of protein, according to a review of scientific literature published in the journalNutrients.
With early nutritional treatment, children with kwashiorkor can recover fully. However, permanent physical and mental impairments can take place if treatment is delayed. If treatment comes too late, shock, coma, and death can result.
A Word From Verywell
As protein is contained in every cell of the body, it’s important to know how it works and how to get enough of it in your diet. However, it’s best to focus more on taking in healthy sources of protein rather than consuming a lot of it.
21 High Protein and Low Calorie Foods
10 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Genetics Home Reference.What are proteins and what do they do?Harvard T.H. Chan School of Public Health.Protein.Ponomarenko EA, Poverennaya EV, Ilgisonis EV, et al.The size of the human proteome: the width and depth.Int J Anal Chem. 2016;2016:7436849. doi:10.1155/2016/7436849Alberts B, Johnson A, Lewis J, et al.Molecular Biology of the Cell. 4th edition. New York: Garland Science. Protein Function.Colorado State University VIVO Pathophysiology.Growth hormone (somatotropin).University of Rochester Medical Center.Ferritin (blood).Fehrenbach KS, Righter AC, Santo RE.A critical examination of the available data sources for estimating meat and protein consumption in the USA.Public Health Nutr. 2016;19(8):1358-1367. doi:10.1017/S1368980015003055U.S. Department of Agriculture.MyPlate, Protein Foods.Mariotti F, Gardner CD.Dietary protein and amino acids in vegetarian diets—a review.Nutrients. 2019;11(11):2661. doi:10.3390/nu11112661MedlinePlus.Kwashiorkor.
10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Genetics Home Reference.What are proteins and what do they do?Harvard T.H. Chan School of Public Health.Protein.Ponomarenko EA, Poverennaya EV, Ilgisonis EV, et al.The size of the human proteome: the width and depth.Int J Anal Chem. 2016;2016:7436849. doi:10.1155/2016/7436849Alberts B, Johnson A, Lewis J, et al.Molecular Biology of the Cell. 4th edition. New York: Garland Science. Protein Function.Colorado State University VIVO Pathophysiology.Growth hormone (somatotropin).University of Rochester Medical Center.Ferritin (blood).Fehrenbach KS, Righter AC, Santo RE.A critical examination of the available data sources for estimating meat and protein consumption in the USA.Public Health Nutr. 2016;19(8):1358-1367. doi:10.1017/S1368980015003055U.S. Department of Agriculture.MyPlate, Protein Foods.Mariotti F, Gardner CD.Dietary protein and amino acids in vegetarian diets—a review.Nutrients. 2019;11(11):2661. doi:10.3390/nu11112661MedlinePlus.Kwashiorkor.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Genetics Home Reference.What are proteins and what do they do?Harvard T.H. Chan School of Public Health.Protein.Ponomarenko EA, Poverennaya EV, Ilgisonis EV, et al.The size of the human proteome: the width and depth.Int J Anal Chem. 2016;2016:7436849. doi:10.1155/2016/7436849Alberts B, Johnson A, Lewis J, et al.Molecular Biology of the Cell. 4th edition. New York: Garland Science. Protein Function.Colorado State University VIVO Pathophysiology.Growth hormone (somatotropin).University of Rochester Medical Center.Ferritin (blood).Fehrenbach KS, Righter AC, Santo RE.A critical examination of the available data sources for estimating meat and protein consumption in the USA.Public Health Nutr. 2016;19(8):1358-1367. doi:10.1017/S1368980015003055U.S. Department of Agriculture.MyPlate, Protein Foods.Mariotti F, Gardner CD.Dietary protein and amino acids in vegetarian diets—a review.Nutrients. 2019;11(11):2661. doi:10.3390/nu11112661MedlinePlus.Kwashiorkor.
Genetics Home Reference.What are proteins and what do they do?
Harvard T.H. Chan School of Public Health.Protein.
Ponomarenko EA, Poverennaya EV, Ilgisonis EV, et al.The size of the human proteome: the width and depth.Int J Anal Chem. 2016;2016:7436849. doi:10.1155/2016/7436849
Alberts B, Johnson A, Lewis J, et al.Molecular Biology of the Cell. 4th edition. New York: Garland Science. Protein Function.
Colorado State University VIVO Pathophysiology.Growth hormone (somatotropin).
University of Rochester Medical Center.Ferritin (blood).
Fehrenbach KS, Righter AC, Santo RE.A critical examination of the available data sources for estimating meat and protein consumption in the USA.Public Health Nutr. 2016;19(8):1358-1367. doi:10.1017/S1368980015003055
U.S. Department of Agriculture.MyPlate, Protein Foods.
Mariotti F, Gardner CD.Dietary protein and amino acids in vegetarian diets—a review.Nutrients. 2019;11(11):2661. doi:10.3390/nu11112661
MedlinePlus.Kwashiorkor.
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