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What Are the Functions of Proteins?
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Antibodies are specialized proteins involved in defending the body from
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What Are the Functions of Proteins?
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Proteins are very important molecules in our cells. They are involved in virtually all cell functions. Each protein within the body has a specific function. There are several types of proteins and their functions. The structure of a protein determines its function.Antibodies are specialized proteins involved in defending the body from antigens (or foreign invaders). One way antibodies destroy antigens is by immobilizing them so that they can be destroyed by white blood cells.Contractile Proteins are responsible for movement. Examples include actin and myosin. These proteins are involved in muscle contraction and movement.Enzymes are proteins that facilitate biochemical reactions. They are often referred to as catalysts because they speed up chemical reactions. Examples include the enzymes lactase and pepsin. Lactase breaks down the sugar lactose found in milk. Pepsin is a digestive enzyme that works in the stomach to break down proteins in food.Hormonal Proteins are messenger proteins which help to coordinate certain bodily activities. Examples include insulin, oxytocin, and somatotropin. Insulin regulates glucose metabolism by controlling the blood-sugar concentration. Oxytocin stimulates contractions in females during childbirth. Somatotropin is a growth hormone that stimulates protein production in muscle cells.Structural Proteins are fibrous and stringy and provide support. Examples include keratin, collagen, and elastin. Keratins strengthen protective coverings such as hair, quills, feathers, horns, and beaks. Collagens and elastin provide support for connective tissues such as tendons and ligaments.Storage Proteins store amino acids. Examples include ovalbumin and casein. Ovalbumin is found in egg whites and casein is a milk-based protein.Transport Proteins are carrier proteins which move molecules from one place to another around the body. Examples include hemoglobin and cytochromes. Hemoglobin transports oxygen through the blood. Cytochromes operate in the electron transport chain as electron carrier proteins.Thanks for watching. To learn more, visit about.com
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