Proteins

• Proteins have carbon, hydrogen, oxygen, & nitrogen.
• Proteins: most diverse structure & function.
• Proteins account for more than 50% of the dry mass of most cells.
• Protein functions are enzymatic proteins, structural support, storage transport, cellular communications, & defense against foreign substances.
• Protein's monomer is Amino Acids.
• Amino Acids: organic molecules with carboxyl and amino groups.
• There are 20 amino acids and their properties differ due to different side chains.
• There are an infinite possibilites of proteins.
• Amino acid structure.

  
• Proteins are linked by peptide bonds.
• Polypeptides are a polymer of amino acids.
• Polypeptides are a string of amino acids and not a protein, but they can become a protein.
• Protein: biologically functional molecule that consists of one or more polypeptides.
• Functional Proteins consist of one or more polypeptides that are twisted, folded, or coiled into a unique shape.
• There are four levels of protein structure.
• Primary Structure: unique sequence of amino acids bonded by peptide bonds.
• Secondary Structure: 3-D folding of primary structure into coils and pleats held by hydrogen bonds.
• Proteins are not functional at the primary and secondary structure.
• Tertiary Structure: bent & folded into an arrangement of linked polypeptides (R group interactions).
• Some proteins are functional in the tertiary structure like enzymes.
• Quaternary Structure: when a protein consists of multiple polypeptide chains.
• Structure matters.
• Hemoglobin: a globular protein consisting of four polypeptides, two alpha and two beta chains.
• Slight change in primary structure can affect a protein's structure and ability to function responsibly for building & breaking things.