Some of the properties of proteins are as follows 1. All proteins contain carbon, hydrogen, oxygen, and nitrogen, the presence of nitrogen distinguishing them from carbohydrates and fats. 2. On an average proteins contain 16% nitrogen.
The two most important shapes taken up by the proteins are globular (spherical shape) and fibrous (rod-type shape). In tertiary protein, ionic bonds are formed when acidic and basic amino acids are ionized and lie close together (4). 1. What are two proteins important in foaming properties of eggs?
However, there is no satisfactory system of classification which depicts the differences and similarities of proteins. One can do the classification of proteins according to their structure, solubility behavior, or their non-protein moiety. Some of these systems of classification are as follow:
Fibrous proteins are highly resistant to digestion by proteolytic enzymes. They function primarily as the chief structural materials of animal tissues, a function to which their insolubility and fiber-forming tendency suit them.
Protein is involved in the creation of some hormones. These substances help control body functions that involve the interaction of several organs. Insulin, a small protein, is an example of a hormone that regulates blood sugar. It involves the interaction of organs such as the pancreas and the liver. Secretin, is another example of a protein hormone. This substance assists in the digestive process by stimulating the pancreas and the intestine to create necessary digestive juices. Enzymes Enzymes are proteins that increase the rate of chemical reactions in the body. In fact, most of the necessary chemical reactions in the body would not efficiently proceed without enzymes. For example, one type of enzyme functions as an aid in digesting large protein, carbohydrate and fat molecules into smaller molecules, while another assists the creation of DNA. Transportation and Storage of Molecules Protein is a major element in transportation of certain molecules. For example, hemoglobin is a protein that transports oxygen throughout the body. Protein is also sometimes used to store certain molecules. Ferritin is an example of a protein that combines with iron for storage in the liver. Antibodies Protein forms antibodies that help prevent infection, illness and disease. These proteins identify and assist in destroying antigens such as bacteria and viruses. They often work in conjunction with the other immune system cells. For example, these antibodies identify and then surround antigens in order to keep them contained until they can be destroyed by white blood cells.
Immunity Antibodies , another protein, help your body fight infection. For each antigen that enters your body, you have a separate and distinct antibody to fight it. Antibodies immobilize and sequester antigens until white blood cells can destroy them. Enzymes Your body performs thousands of biochemical reactions a day to function properly. These reactions require energy, and many have significantly high energy thresholds that can delay essential reactions. Proteins called enzymes assist in lowering the activation energy of hundreds of reactions, helping them to proceed thousands of times faster than they would in a normal environment. A well-known example of an enzyme is lactase, which facilitates the metabolism of lactose, or milk sugar, in your small intestine to aid in digestion. Hormones Hormones are proteins that send signals and coordinate activities throughout the body. Examples include insulin, which facilitates glucose metabolism and controls blood glucose levels; thyroid hormones, which regulate metabolism, body temperature and the synthesis of other proteins; and gonadotropins, which stimulate the production of sperm and ova. Transport Transport proteins carry other proteins and compounds throughout the body. Hemoglobin is a type of transport protein present in red blood cells; it carries oxygen from the lungs to all tissues and cells and transports carbon dioxide, a metabolic waste product, back to the lungs for excretion from the body. Energy Your body can use protein for its energy needs when carbohydrates are depleted. When needed, proteins degrade into their component amino acids, which are then oxidized in the same process as glucose to create energy. However, prolonged use of protein for energy can cause problems if not enough protein remains to perform its essential functions, according to “Human Physiology.”
Muscle Contraction Actin and myosin are two specialized types of filament protein present in your muscle. When stimulated by a signal from the central nervous system, these two proteins act in unison to shorten in length, causing your muscle to contract.
oxygen through the blood via red blood cells . Cytochromes operate in the electron transport chain as electron carrier proteins. Protein Structure There are four levels of protein structure . These levels are distinguished from one another by the degree of complexity in the polypeptide chain (linked amino acids). The four levels of protein structure are primary, secondary, tertiary, and quaternary structure. A single protein molecule may contain one or more of these protein structure types. The structure of a protein determines its function.
Fibrous proteins are highly resistant to digestion by proteolytic enzymes. They function primarily as the chief structural materials of animal tissues, a function to which their insolubility and fiber-forming tendency suit them.
In these proteins, the prosthetic group possesses phosphoric acid in some form other than in the nucleic acids or in the lipoproteins. Casein is an example of phosphoproteins.
Because of this, the intermolecular forces that must be overcome by a solvent are very strong , and that’s why they are insoluble in water.
The polymers of amino acids are peptides and large peptides are called proteins. Proteins are macromolecules that are constructed by the repetition of one or more structural elements, called monomers. In the case of proteins, the monomers are a group of about 20 amino acids. Proteins have different properties thus the properties of proteins are discussed below.
According to this system of classification, proteins may be divided into three main groups:
Proteins are now defined as complex nitrogenous substances which are found in the protoplasm of all animal and plant cells. The term “protein”, derived from the Greek word proteios meaning first, was first of all used by Mulder in 1839 at the suggestion of Berzelius. Mainly proteins are biopolymers containing a large number of amino acids joined to each other by peptide bonds.
These proteins are formed by the union of nucleic acid with two molecules of proteins. The nucleoproteins are DNA and RNA.