Introduction to Proteins

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


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