What are proteins???• Hair• Fur• Muscles• Chemical messengers between cells• Most diverse functions of any of the

macromolecules we have discussed!!!

PROTEINSPROTEINSPROTEINPROTEIN: : aa POLYMERPOLYMER constructed from a set of just constructed from a set of just 2020 kinds of kinds of monomers calledmonomers called AMINO ACIDSAMINO ACIDS..

AMINO ACIDAMINO ACID: : consists of a consists of a CENTRAL CARBON ATOMCENTRAL CARBON ATOM bonded to bonded to FOUR PARTNERSFOUR PARTNERS. . THREETHREE of these partners of these partners AREARE alwaysalways THE THE SAMESAME..

•The side group or The side group or FOURTH PARTNERFOURTH PARTNER is different. The is different. The DIFFERENT SIDE DIFFERENT SIDE GROUPSGROUPS are responsible for the are responsible for the DIFFERENT CHEMICAL PROPERTIESDIFFERENT CHEMICAL PROPERTIES of of each amino acid.each amino acid.

PROTEIN SHAPEPROTEIN SHAPEPOLYPEPTIDEPOLYPEPTIDE: : amino acids linked together in a amino acids linked together in a chain (most are about 100 AA in length)chain (most are about 100 AA in length)

• PROTEINSPROTEINS areare ONE OR MORE POLYPEPTIDE ONE OR MORE POLYPEPTIDE CHAINSCHAINS linked together.linked together.

Proteins must be Proteins must be PRECISELY TWISTEDPRECISELY TWISTED, , FOLDEDFOLDED, and , and COILEDCOILED into a into a UNIQUE SHAPEUNIQUE SHAPE in order to work. in order to work. (Ball of yarn vs. a sweater, same material different (Ball of yarn vs. a sweater, same material different functions)functions)

• DENATURATIONDENATURATION: change in temperature, pH, or some : change in temperature, pH, or some other quality of the environment that other quality of the environment that CAUSES A PROTEINCAUSES A PROTEIN TO UNRAVELTO UNRAVEL and and LOSE ITS NORMAL SHAPELOSE ITS NORMAL SHAPE..

EXAMPLEEXAMPLECooking an egg: the egg white Cooking an egg: the egg white

changes from a clear liquid to a changes from a clear liquid to a white solid during cooking white solid during cooking because heat denatures the egg’s because heat denatures the egg’s proteins.proteins.

PROTEIN FUNCTIONSPROTEIN FUNCTIONSPROTEIN FUNCTIONSPROTEIN FUNCTIONS

•Used in Used in BODY STRUCTURESBODY STRUCTURESExamples: hair, fingernails, muscle fibersExamples: hair, fingernails, muscle fibers

•Responsible for Responsible for TRANSPORTTRANSPORTExample: Hemoglobin, a protein, transports Example: Hemoglobin, a protein, transports OO22 in the blood in the blood

• FIGHT DISEASEFIGHT DISEASEExample: Antibodies are proteins that attach Example: Antibodies are proteins that attach to foreign molecules to provoke immune to foreign molecules to provoke immune responseresponse

• CHEMICAL MESSENGERSCHEMICAL MESSENGERSExample: Insulin, a hormone, regulates the Example: Insulin, a hormone, regulates the level of glucose in your bloodlevel of glucose in your blood

• ENZYMESENZYMES control reaction ratescontrol reaction rates

NUCLEIC ACIDSNUCLEIC ACIDSNUCLEIC ACIDNUCLEIC ACID: : large nitrogen-containing polymers large nitrogen-containing polymers found mainly in the nuclei of cells.found mainly in the nuclei of cells.

DEOXYRIBONUCLEIC ACID (DNA)DEOXYRIBONUCLEIC ACID (DNA): : POLYMERPOLYMER built from built from monomers calledmonomers called NUCLEOTIDESNUCLEOTIDES and contains the sugar and contains the sugar deoxyribose. (There are only four nucleotides that make deoxyribose. (There are only four nucleotides that make up DNA: A, T, C, and G.) up DNA: A, T, C, and G.)

•StoresStores HEREDITARY INFORMATIONHEREDITARY INFORMATION• CONTROLS ACTIVITIESCONTROLS ACTIVITIES of cellsof cells

RIBONUCLEIC ACID (RNA)RIBONUCLEIC ACID (RNA): : POLYMERPOLYMER built from monomers built from monomers calledcalled NUCLEOTIDESNUCLEOTIDES and contains the sugar ribose.and contains the sugar ribose.

•Works with DNA to Works with DNA to BUILD PROTEINSBUILD PROTEINS

NUCLEOTIDENUCLEOTIDE