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5.2: Introduction to Proteins

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    Describe the structure and function proteins

    Proteins are polymers of amino acids. Each amino acid contains a central carbon, a hydrogen, a carboxyl group, an amino group, and a variable R group. The R group specifies which class of amino acids it belongs to: electrically charged hydrophilic side chains, polar but uncharged side chains, nonpolar hydrophobic side chains, and special cases.

    Proteins have different “layers” of structure: primary, secondary, tertiary, quaternary.

    Proteins have a variety of function in cells. Major functions include acting as enzymes, receptors, transport molecules, regulatory proteins for gene expression, and so on. Enzymes are biological catalysts that speed up a chemical reaction without being permanently altered. They have “active sites” where the substrate/reactant binds, and they can be either activated or inhibited (competitive and/or noncompetitive inhibitors).

    What You’ll Learn to Do

    • Demonstrate familiarity with monomeric units of proteins: amino acids
    • Define the different layers of protein structure
    • Identify several major functions of proteins

    Learning Activities

    The learning activities for this section include the following:

    • Amino Acids
    • Protein Structure
    • Function of Proteins
    • Self Check: Proteins

    Contributors and Attributions

    CC licensed content, Original
    • Introduction to Proteins. Authored by: Shelli Carter and Lumen Learning. Provided by: Lumen Learning. License: CC BY: Attribution

    5.2: Introduction to Proteins is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.

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