BCHM 3050 1st Edition Lecture 11 Outline of Last Lecture I Enzymes II Introductory Terminology III Models for Enzyme Action IV Energy Changes During the Progress of a Reaction V Six Classes of Enzymes a Oxidoreductases b Transferases c Hydrolases d Lysases e Isomerases f Ligases Outline of Current Lecture I How does liquidy syrup inside candies form II Substrate Concentration has the Greatest Effect III Initial Velocity is Fastest IV Importance of Vmax and Km V Significance of Km VI Experimental Determination of Vmax and Km VII The Michaelis Menton Equation VIII Lineweaver Burk Plots Current Lecture I How does liquidy syrup inside candies form a Invertase enzyme makes candies more creamy than granular more liquidy than solid These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute b Breaks down sucrose into glucose and fructose to keep it a syrup consistency II Substrate Concentration has the Greatest Effect a Need substrate for enzyme to react more reactants better acting enzyme b c more substrates for it to bind to b Velocity rate of enzyme function c Enzyme will not exceed it pre set maximum velocity d Vmax Rmax the maximum possible velocity that a reaction can have e Vmax 2 half maximum velocity of reaction that corresponds to Km constant in substrate concentration f III Km how well a substrate and an enzyme react Initial Velocity is Fastest a Dashed line excellent ideal enzyme but doesn t exist b c all enzymes function plateau b Rate of the very beginning of the graph is the initial velocity the closer to a straight line the better the enzyme c Substrate concentrations gradually decrease d Reaction velocities slow down with time e Reverse reaction starts to occur f IV Initial velocities are the most relevant Importance of Vmax and Km a Both are constants that help define enzymes b Rarely operate at true Vmax not always enough substrates to get substrate to its full potential i Substrate concentration in cells is not usually high enough ii Substrate at Km is more realistic c Most enzymes work at half of their Vmax at Km d Km is an indication of enzyme affinity for substrate V Significance of Km a The lower the Km the better the enzyme lowers the Vmax which decreases the energy needed for the enzyme to function at its best b Lower Km enzyme will bind tighter to the substrate graph will be more hyperbolic c Fructose has higher substrate affinity because it has a lower Km lower Vmax functions better VI Experimental Determination of Vmax and Km a Above graph allows estimation of Vmax Km b Estimations would be easier if working with a straight line c Lineweaver Burke plots are linear transformations of hyperbolic plots VII The Michaelis Menton Equation a Leonor Michaelis and Maud Menten developed the hyperbolic relationships and their equation in 1907 b Michaelis Menton equation can be used to predict the velocity of a reaction at a given substrate concentration assuming you know the the Km Vmax constants c V Vmax x S S Km VIII Lineweaver Burk Plots a Lineweaver Burk developed their double reciprocal plot in 1934 b Reciprocal of Michaelis Menton equation is a slightly better way of representing it c V Vmax x S S Km
View Full Document
Unlocking...