primary structure of protein download free

Protein shape is critical to its function, and many different types of chemical bonds maintain this shape. For example, hemoglobin is a globular protein, but collagen, located in our skin, is a fibrous protein. Some proteins are globular in shape whereas, others are fibrous in nature. Proteins have different shapes and molecular weights. Table 3.1 lists the primary types and functions of proteins. For example, insulin is a protein hormone that helps regulate the blood glucose level. Hormones are chemical-signaling molecules, usually small proteins or steroids, secreted by endocrine cells that act to control or regulate specific physiological processes, including growth, development, metabolism, and reproduction. An example of an enzyme is salivary amylase, which hydrolyzes its substrate amylose, a component of starch. Note that all enzymes increase the reaction rate and, therefore, are organic catalysts. Those that build more complex molecules from their substrates are anabolic enzymes, and enzymes that affect the rate of reaction are catalytic enzymes. We call enzymes that break down their substrates catabolic enzymes. The enzyme may help in breakdown, rearrangement, or synthesis reactions. Each enzyme is specific for the substrate (a reactant that binds to an enzyme) upon which it acts. Types and Functions of ProteinsĮnzymes, which living cells produce, are catalysts in biochemical reactions (like digestion) and are usually complex or conjugated proteins. They are all, however, amino acid polymers arranged in a linear sequence. Their structures, like their functions, vary greatly. Each cell in a living system may contain thousands of proteins, each with a unique function. They may serve in transport, storage, or membranes or they may be toxins or enzymes. Proteins may be structural, regulatory, contractile, or protective. Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Describe the ways in which protein shape and function are linked.Explain the four levels of protein organization.Discuss the relationship between amino acids and proteins.

Describe the functions proteins perform in the cell and in tissues.

By the end of this section, you will be able to do the following:

Primary structure of protein download free