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.
The learning activities for this section include the following:
- Reading: Amino Acids
- Reading: Protein Structure
- Reading: Function of Proteins
- Self Check: Proteins