What are proteins??? Hair Fur Muscles Chemical messengers between cells Most diverse functions of any of the macromolecules we have discussed!!!

PROTEINS PROTEIN: a POLYMER constructed from a set of just 20 kinds of monomers called AMINO ACIDS. AMINO ACID: consists of a CENTRAL CARBON ATOM bonded to FOUR PARTNERS. THREE of these partners ARE always THE SAME. The side group or FOURTH PARTNER is different. The DIFFERENT SIDE GROUPS are responsible for the DIFFERENT CHEMICAL PROPERTIES of each amino acid. The side group or FOURTH PARTNER is different. The DIFFERENT SIDE GROUPS are responsible for the DIFFERENT CHEMICAL PROPERTIES of each amino acid.

PROTEIN SHAPE POLYPEPTIDE: amino acids linked together in a chain (most are about 100 AA in length) PROTEINS are ONE OR MORE POLYPEPTIDE CHAINS linked together. PROTEINS are ONE OR MORE POLYPEPTIDE CHAINS linked together.

Proteins must be PRECISELY TWISTED, FOLDED, and COILED into a UNIQUE SHAPE in order to work. (Ball of yarn vs. a sweater, same material different functions) DENATURATION: change in temperature, pH, or some other quality of the environment that CAUSES A PROTEIN TO UNRAVEL and LOSE ITS NORMAL SHAPE. DENATURATION: change in temperature, pH, or some other quality of the environment that CAUSES A PROTEIN TO UNRAVEL and LOSE ITS NORMAL SHAPE. EXAMPLE Cooking an egg: the egg white changes from a clear liquid to a white solid during cooking because heat denatures the egg’s proteins.

PROTEIN FUNCTIONS Used in BODY STRUCTURES Used in BODY STRUCTURES Examples: hair, fingernails, muscle fibers Responsible for TRANSPORT Responsible for TRANSPORT Example: Hemoglobin, a protein, transports O 2 in the blood FIGHT DISEASE FIGHT DISEASE Example: Antibodies are proteins that attach to foreign molecules to provoke immune response CHEMICAL MESSENGERS CHEMICAL MESSENGERS Example: Insulin, a hormone, regulates the level of glucose in your blood ENZYMES control reaction rates ENZYMES control reaction rates

NUCLEIC ACIDS NUCLEIC ACID: large nitrogen-containing polymers found mainly in the nuclei of cells. DEOXYRIBONUCLEIC ACID (DNA): POLYMER built from monomers called NUCLEOTIDES and contains the sugar deoxyribose. (There are only four nucleotides that make up DNA: A, T, C, and G.) Stores HEREDITARY INFORMATION Stores HEREDITARY INFORMATION CONTROLS ACTIVITIES of cells CONTROLS ACTIVITIES of cells RIBONUCLEIC ACID (RNA): POLYMER built from monomers called NUCLEOTIDES and contains the sugar ribose. Works with DNA to BUILD PROTEINS Works with DNA to BUILD PROTEINS NUCLEOTIDE