PROTEINS STRUCTURAL AND FUNCTIONAL COMPOUNDS OF UNIVERSAL IMPORTANCE TO ALL LIVING THINGS

PROTEINS n n MADE OF MONOMERS CALLED AMINO ACIDS n n OFTEN REFERRED TO AS POLYPEPTIDES BECAUSE OF THE TYPE OF BONDING INVOLVED n n EACH SPECIES HAS THOUSANDS OF UNIQUE PROTEINS VARY IN THE NUMBER OF AMINO ACID RESIDUES VARY IN THE SEQUENCE OF AMINO ACID RESIDUES VARY IN THE SPECIFIC AMINO ACIDS PRESENT IN EACH PROTEIN VARY IN SECONDARY FEATURES LIKE CROSS- BONDING BETWEEN AMINO ACIDS

STRUCTURE OF AMINO ACIDS CCN H H H H O O R AMINE GROUP CARBOXYL GROUP RADICAL GROUP ONLY THE RADICAL GROUP VARIES BETWEEN AMINO ACIDS

CCN H H H H O O H THREONINE GLYCINE SERINE CCN H H H H O O H HHC ALANINE CCN H H H H O O CHH OH CCN H H H H O O HC OCHH H H H

PEPTIDE BONDING CCN H H H H O O R CCN H H H H O O R CCN H H H O R CCN HH H O O R H2OH2O AMINO ACIDS DIPEPTIDE ONLY 2 AMINO ACIDS

POLYPEPTIDES CCN H H H O R CCN H H O R CCN H H O R CCN HH H O O R COMPOSED OF 3 OR MORE AMINO ACIDS

Energy n Chemical energy – found in food serves as the primary source. n Energy is the ability to move or change matter n Exists in many forms (heat, light, chemical, mechanical, and electrical) n Can be converted from one form to another. n Can be stored or released by chemical reactions.

Chemical Reactions n Process during which chemical bonds between atoms are broken and new ones are formed. n Reactants – the starting materials of a chemical reaction. n Products – newly formed substances formed Reactants  Products n Arrow means “changes to or yields” H 2 + O 2  H 2 O

Energy in Chemical Reactions n Energy is absorbed or released when chemical bonds are broken or when new bonds are formed. n Endothermic reactions – when energy is absorbed to change reactants to products. n Exothermic reactions – when energy is released as reactants are changed into products.

Activation Energy n The energy needed to start a chemical reaction n Like the match needed to start a fire or the spark from the spark plug needed to ignite the gasoline in an engine. n Like a chemical “push” that starts a chemical reaction. n All chemical reactions require some activation energy, even exothermic reactions

ENZYMES PROTEINS THAT ACT AS CATALYSTS IN INTERMEDIARY METABOLISM

ENZYMES n n ESSENTIAL FOR THE PROPER FUNCTIONING OF ANY CELL n n SPEED UP SPECIFIC CHEMICAL REACTIONS BY LOWERING ACTIVATION ENERGY NECESSARY FOR REACTION n n REACTANT IS KNOWN AS THE SUBSTRATE n n FORMS A LOCK AND KEY ARRANGEMENT WHICH IS BELIEVED TO WEAKEN CHEMICAL BONDS WITHIN THE SUBSTRATE n n THUS IT REQUIRES LESS ENERGY TO MAKE THE REACTION HAPPEN n n THE ENZYME IS NOT USED UP IN THE REACTION AND THEREFORE CAN GO ON TO CATALYZE ADDITIONAL REACTIONS

LOCK AND KEY MECHANISM ENZYME SUBSTRATE ENZYME PRODUCTS ENZYME SUBSTRATE ENZYME BINDS IN AN EXACT FIT TO A SPECIFIC SITE ON A SUBSTRATE MOLECULE ENZYME - SUBSTRATE COMPLEX PLACES STRESS ON BONDS LOWERING ACTIVATION ENERGY FINALLY BONDS ARE WEAKENED ENOUGH TO BREAK AND PRODUCTS SEPERATE AND ARE RELEASED FOR USE BY THE CELL

NUCLEIC ACIDS COMPLEX ORGANIC MOLECULES WHICH STORE IMPORTANT INFORMATION WITHIN A CELL

NUCLEIC ACIDS CG TA S S S S P P P P TA CG S S S S P P P P CG TA S S S S P P P P CG TA S S S S P P P P TA CG S S S S P P P P CG TA S S S S P P P P DNA DEOXYRIBONUCLEIC ACID STORES INFORMATION ESSENTIALTO MOST CELL ACTIVITIES SUCH AS CELL DIVISION AND PROTEIN SYNTHESIS

NUCLEIC ACIDS U C S S P P G U S S P P C A S S P P C S G U S S P P U S P P C A S S P P RNA RIBONUCLEIC ACID STORES AND TRANSFERS INFORMATION NECESSARY FOR THE MANUFACTURE OF PROTEINS WITHIN THE CELL

NUCLEIC ACIDS PHOSPHATE GROUP PO 4 PENTOSE SUGAR NITROGEN BASE ADENINE THYMINE CYTOSINE GUANINE RIBOSE OR DEOXYRIBOSE NUCLEOTIDE BASIC UNIT OF ALL NUCLEIC ACIDS