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Biofuel Enzymes. A Study of Enzyme Kinetics. Enzymes. Speed up the rate of reactions Generally proteins Have active site in cleft of protein where reactions take place The charges and positions of the R groups (variable side chains) amino acids critical for activity of enzyme.
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Biofuel Enzymes A Study of Enzyme Kinetics
Enzymes • Speed up the rate of reactions • Generally proteins • Have active site in cleft of protein where reactions take place • The charges and positions of the R groups (variable side chains) amino acids critical for activity of enzyme. • Active site is where reactants binds
Enzymes • Enzymes position the substrate (reactants) in such a way as to lower the energy needed for the reaction to occur.
Enzyme Factors • Changes in salinity affect side chains in active site • Changes in pH affect side chains in active site • Temperature affects the activity of an enzyme • Relative concentration of both substrates and enzymes affect the rate of reaction (Vmax).
Cellulosic Ethanol Production • Pretreat to remove non-cellulose biomolecules such as lignin • Enzymatic Hydrolysis uses cellulases to produce six carbon sugars such as glucose • Microbial fermentation converts sugars into ethanol.
Cellulose vs Cellulase • Cellulose makes up cell wall in plants • Cellulose in form of cellulose microfibrils and hemicellulose • Cellulases break down cellulose into glucose • Animals do not make produce cellulases
Types of Cellulases • Endocellulases – break down internal bonds within a long chain of glucose molecules • Exocellulases – break the bonds on the ends of the cellulose to create two sugar cellobiose • Cellobiases- break the bonds in cellobiose to make two glucose sugars
Studying Cellobiase • Can’t quantitatively detect presence of glucose or absence of cellobiose • Use artificial substrate of p-nitrophenyl glucopyranoside (PNPG) • When PNPG is cleaved by the cellobiase, it produces p-nitrophenol. If you add a base to p-nitrophenol, it will turn yellow. • The deepness of yellow color can be compared visually or by spectrophotometry to produce quantitative results
To study Enzyme Kinetics we will: • Determine the Rate of Reaction in the Presence or Absence of an Enzyme • Determine the Effect of Temperature on the Reaction Rate • Determine the Effect of pH on the Reaction Rate • Determine the Effect of Enzyme Concentration on the Reaction Rate • Determine the Effect of Substrate Concentration of Reaction Rate • Test the Ability of Mushroom Extracts to Increase the Reaction Rate