Polymers of amino acids linked by peptide bonds. The specific sequence of amino acids determines the shape and function of the protein.
An essential nutrient. Proteins are compounds of carbons, hydrogen, oxygen, and nitrogen arranged into strands called amino acids.
Required listing on nutrition label. Protein provides about 4 g of calories per gram. A dietary source of amino acids and nitrogen required for growth, maintenance and general well-being of humans.
Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of alpha‐amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. Their roles include enzymatic catalysis, transport and storage, coordinated motion, nerve impulse generation and transmission, control of growth and differentiation, immunity, and mechanical support.
All living tissues contain proteins; they are polymers of amino acids, joined by peptide bonds. There are 21 main amino acids in proteins, and any one protein may contain several hundred or over a thousand amino acids, so an enormous variety of different proteins occur in nature. Generally a polymer of relatively few amino acids is referred to as a peptide (e.g. di-, tri-, and tetrapeptides); oligopeptides contain up to about 50 amino acids; larger molecules are polypeptides or proteins.
A compound composed of carbon, hydrogen, oxygen, and nitrogen, arranged into amino acids linked in a chain, responsible for building and repair of tissue, hormone production, enzyme function.
A molecule made up of amino acids that are needed for the body to function properly. Proteins are the basis of body structures such as skin and hair and of substances such as enzymes, cytokines, and antibodies.
From the Greek wordproteios, which means “the first” or “the most important.” Any of a class of high molecular weight polymer compounds composed of a variety of a-amino acids joined by peptide linkages. Via the synthesis (of this “chain”) performed by ribosomes, each protein is the ultimate expression product of a gene. Proteins are the “workhorses” of living systems and include enzymes, antibodies, receptors, peptide hormones, etc. All of the amino acids commonly found in proteins have an asymmetric carbon atom, except the amino acid glycine. Thus the protein is potentially chiral in nature.
Compounds containing hydrogen, oxygen, and nitrogen that are present in the body and in foods formed by complex combinations of amino acids. Protein is essential for life. Foods that supply the body with protein include meats, dairy products, eggs, and seafood, as well as grains, legumes, nuts, and vegetables.
One of six major classes of nutrients.
Organic compounds made up of amino acids.
A nitrogen compound which is present in and is an essential part of all living cells in the body, formed by the linking of amino acids.
Macro-nutrients present in food, used by the body for building tissues and complex enzymes, and as a source of energy; chemically they consist of amino acids linked in straight head-to-tail chains.
A nutrient that is necessary for the building and repair of body tissues.
Nutrient that supplies the building material for the body, including muscles, skin, hair, nails and internal organs such as the heart and brain. Protein is made up of amino acids and is classified as ‘complete’ or ‘incomplete’ depending on the amount and ratio of the essential amino acids. Animal products are rich sources of protein.
A large group of complex molecules that are polymers of amino acids. They are classified as simple proteins or conjugated proteins. Simple proteins have no prosthetic group attached. Examples include albumins, globulins, glutelins, scleroproteins, prolamines, and protamines. Conjugated proteins are characterized by the type of prosthetic group attached to the protein. The prosthetic group can be a carbohydrate (glycoprotein), a lipid (lipoprotein), or other material. The metalloproteins, mucoproteins, nucleoproteins, hemoproteins, and flavoproteins are conjugated proteins.
Proteins are characterized by many amino acids linked together by peptide bonds. Proteins are often defined as having at least 50 amino acids, while others suggest that at least 100 amino acids are needed for a molecule to be considered a protein. Those molecules with less amino acids in their structures are considered polypeptides. Foods rich in protein include meat, fish, poultry, eggs, legumes, diary foods, and others. Protein is also found in nuts, seeds, grains, and vegetables, while very little is present in fruits. Protein is needed in the diet because it provides essential amino acids, which are described in a separate entry.
Complex chemical compounds, made up of amino acids, that are vital to the body’s functioning, not only forming the structure of many parts of the body but also promoting many of the most basic biochemical reactions in the body. Com¬ mon sources of protein are meat, poultry, fish, eggs, milk, and cheese, called complete proteins because they contain all of the essential amino acids. Other sources of proteins that contain some, but not all, essential amino acids are nuts, beans, and peas.
Any of a large group of complex compounds, containing carbon, hydrogen, oxygen, nitrogen, and sometimes phosphorus and sulfur, and consisting of chains of amino acids joined by peptide bonds. Proteins form the structural part of most organs, and make up enzymes and hormones that regulate body functions. They are synthesized in the body from their constituent amino acids, obtained in the diet.
A nitrogenous compound found in blood, CSF, and urine, essential to tissue growth and repair. Abnormal blood levels may indicate kidney, liver, and other diseases, abnormal CSF levels may indicate inflammation of the brain or spinal cord or brain hemorrhage; abnormal urine levels may indicate kidney disease.
Complex organic compounds found in every living cell. Proteins are made up of chains of amino acids containing carbon, hydrogen, oxygen, and nitrogen. Protein is necessary in the diet to provide the body with adequate amino acids for building proteins. Proteins are the main component of muscles, organs, and glands. The cells of muscles, tendons, and ligaments are maintained with protein.
One of a group of organic compounds of carbon, hydrogen, oxygen, and nitrogen (sulfur and phosphorus may also be present). The protein molecule is a complex structure made up of one or more chains of amino acids, which are linked by peptide bonds. Proteins are essential constituents of the body; they form the structural material of muscles, tissues, organs, etc., and are equally important as regulators of function, as enzymes and hormones. Proteins are synthesized in the body from their constituent amino acids, which are obtained from the digestion of protein in the diet. Excess protein, not required by the body, can be converted into glucose and used as an energy source.
The term applies to members of a group of non-crystallisable nitrogenous substances widely distributed in the animal and vegetable kingdoms, and forming the characteristic materials of their tissues and fluids. They are essentially combinations of amino acids. Typical examples of protein substances are white of egg and gelatin.
One of a class of complex nitrogenous compounds that are synthesized by all living organisms and yield amino acids when hydrolyzed. Proteins in the diet provide the amino acids necessary for the growth and repair of animal tissue.
Nitrogenous substances of high molecular weight which on hydrolysis give amino-acids.
A nitrogen-containing compound found in plant and animal foods. The body uses protein as a fuel source and to form or repair tissues, organs, and muscles. It comprises enzymes and hormones, and is found in every cell in the body. Amino acids are the individual building blocks of protein. There are approximately 20 different amino acids.
Protein builds and repairs tissue; maintains chemical balance; and regulates the formation of hormones, antibodies, and enzymes. Large amounts of protein are found in both animal sources (meat, dairy) and plant sources (beans, nuts, grains).
A class of nutrients that are made up of amino acids, which are needed to build and repair body structures and to regulate processes in the body.
Nutrient made up of amino acids that is needed for growth to build, repair, and maintain body tissues.
A large complex molecule made up of one or more chains of amino acids. Proteins perform a wide variety of activities in the cell.
The class of nutrients that contain nitrogen as well as carbon, hydrogen, and oxygen; besides being a source of energy, proteins play an important role in the growth and repair of body tissues.
Complex organic compounds containing nitrogen and formed by combinations of amino acids. Proteins are the main substances used in the body to build and repair tissues such as muscles, blood, internal organs, skin, hair, nails, and bones. They are also part of hormones, antibodies, and enzymes.
Protein, a fundamental nutrient, is primarily obtained from animal products and legumes. This essential macronutrient plays a critical role as a building block for growth, recovery, and rejuvenation in the human body. Moreover, protein can serve as a more effective energy source than fat in the absence of sufficient carbohydrate intake.
Protein-rich foods are those that contain a significant amount of amino acid compounds, which are vital for the growth, repair, and regeneration of living cells in an organism. Major sources of protein include meat, fish, eggs, milk, cereal grains, and legumes.
Protein, a fundamental component found within the cells of both animals and plants, plays a crucial role in biological structures. Within the realm of animal anatomy, all muscular tissues are constructed from proteins, thereby highlighting their indispensable nature for the growth and restoration of the human body. This vital nutrient assumes utmost importance for individuals at various life stages, including growing children and adults, as it facilitates essential processes such as tissue development and repair. Moreover, protein serves as a source of energy and warmth, contributing to the overall vitality and well-being of individuals.
Series of amino acids that serve as vital building blocks within every living cell. They encompass structural elements, enzymes, hormones, and antibodies.
Complex compounds comprising numerous amino acids joined together in extensive chains, often numbering hundreds or thousands. Proteins can also be paired with sugars, resulting in glycoproteins, as well as with lipids, forming lipoproteins.
Two primary categories of proteins exist. The initial category, known as fibrous proteins, possess low solubility and establish the foundational framework for numerous bodily tissues. The subsequent category, referred to as globular proteins, exhibit solubility and encompass various enzymes, a multitude of hormones, and specific blood proteins like hemoglobin. Additionally, chromosomes within cell nuclei are structured using proteins connected to nucleic acids, while cell walls are partially constructed through proteins associated with lipids.
The primary purpose of dietary proteins is to furnish the body with amino acids. Upon consumption, ingested proteins undergo breakdown within the digestive system, resulting in the formation of amino acids. These amino acids are subsequently assimilated and utilized to synthesize fresh body proteins.
Proteins are a group of complex nitrogen-containing substances with a high molecular weight. They are present in various forms in both animals and plants and are a defining feature of living organisms. When proteins undergo hydrolysis, they break down into amino acids. In the human diet, protein sources are abundant and primarily come from the meat of mammals, birds, and fish. Protein plays a crucial role in replacing the body’s worn-out tissues. In addition to protein, the human diet includes other essential components such as carbohydrates, fats, salts, chemicals, water, and vitamins.