Proteins and Nucleic Acids

Amino acids are the building blocks of proteins

Side chains (R groups) give amino acids their various properties (polar, nonpolar)

Amino acids combine to form polypeptides (polymers) via loss of ____ molecules

Protein FunctionMost diverse of all organic compoundsBody Structure - Hair, muscle, collagen, bones, feathers, spider websMobility/transport - actin and myosin in muscles, hemoglobinDefense - antibodiesStorage - Casein in milk, proteins in eggs, seedsHormones - insulin Catalysts for all reactions within cells (enzymes)

EnzymesEnzymes = Organic catalystsSpeed up chemical reactionsNot changed by the reactionLower start up energy (activation energy) required for reactionExtremely specificEach chemical reaction requires a different enzyme

Enzyme Activity: Lock and Key ModelSubstrate = molecule acted on by enzymeActive site = surface cleft on enzyme that binds to substrateInduced fit = enzyme changes shape of active site so substrate can bind

How do Enzymes Speed Up Reactions?http://www.lew-port.com/10712041113402793/lib/10712041113402793/Animations/Enzyme_activity.htmlAnabolic reactionsBring two substrates together (greater chance of reaction)Catabolic reactionsStress bonds (greater chance of bonds breaking)

Factors Affecting Enzyme ActivityTemperature

pH

Concentration of SubstrateDenaturing (enzyme changes shape, stops working)

Why is protein structure important for its function? Shape defines its functionShape is obtained by the precise interactions of the R groupsR groups change - protein folds differently (sickle cell anemia)Sensitive to changes in cell environment - anything that will change/break H bonds, acidity/basicity

Nucleic AcidsBuilding blocks are nucleotidesEach nucleotide made up of A 5-carbon sugarRNA: riboseDNA: deoxyriboseNitrogenous base Adenine, Cytosine, Guanine, Thymine (DNA only), Uracil (RNA only)Phosphate group(s)Basic Structure of a Nucleotide

Comparison of Nucleic AcidsDNADouble strandedDeoxyriboseBases: CGATRNASingle strandedRiboseBases: CGAU

Function of Nucleic acidsDNA contains all the info the cell needs to survive and carry out its functionsRNA - carries out the job that is specified on DNA (makes proteins)ATP (Adenosine triphosphate) is the fuel for cell to work Coenzymes help enzymes do their work eg NAD, FADMessengers within cell e.g. cAMP