Lecture 9 - Part 2

• ( S  P) competes (P  S) • [S] ↓ • Enzyme becomes Unstable • P may inhibit Enzyme Subrstrate and product. Rate of rxn decreases with time and eventuqlly stops

Required by some “E” Denatures some “E”

Oxidoreductase Transfers H+ or electrons

Uses water to break bond

Adds or removes groups to / from double bond

Links two molecules

Catalyzes geometric changes -Glucose isomersae converts glucose to fructose

Enzyme used in foo processing Breaks α (1-4) Linkages: Starch Hydrolysis Starch  Maltose + Dextrin -Breaks it down into these corter chain carbs , still polysaccharides but smaller than starch Viscosity: Larger molucule the larger the viscosity

Enzymes used in food processing Invertase (Sucrase) Sucrose  Glucose + Fructose -Makes invert sugars Candy Industry

Enzyme used in food processing (Lactase) Lactose > Galactose + Glucose Some people can lac this enzyme ini their intestines

Enzyme used in food processing Breaks β (1-4) Linkages Cellulose β-Dextrin, Glucose + Xylose Humans don’t have this enzyme and why we cant eat grass

Cellulase (Hydrolyze the cellulose polymer) in juice and wine industry Break the b1-4 links This enzyme acts on fruit tissue  Liquefy the tissue More juice could be extracted

Found naturally in fruits and vegetables Used in Fruit/Vegetable juice industry • Breaks down the cellular structures of fruits and vegetables to allow for maximum extraction of the juice Hydrolyse pectin bond

Hydrolyze Polymer Chain which results in: Cloud Formation in the fruit juice Then the cloud is Filtered Out Clarify Fruit Juices (Apple)/Wine

Pectin Esterase (breaks off –OCH3 group) Cloud Formation> Filter Out Cloud > Clear Juice/Wine

Enzymes used in food processing Phenolic into O-Quinone (Brown Colour) Desirable? Tea, Coffee Undesirable? Fresh Fruits (Apples…)

β-D-Glucose + 02 > D–Glucono-δ-Lactone + H202 Hydrogen peroxide and add the enzyme so we convert it into water

H202 > H20 + ½ 02 -Remove 50% of the O2 in the making of fruit juices, and leads to less chane in browning rxns to tak eplace In Citrus Industry, these enzymes are used to remove 02 from the headspace of fruit juices Net Result: Uptake of ½ molecule of 02

aka esterase Lipase breaks Tri-A.G. down in a step-wise manner: TRI -A.G. > DI- A.G. > MONO- A.G. + F.A. -Breaks ester bonds in a step wise manner (tri to di to mono )

Require Specific A.A > to break the peptide bond Trypsin: Hydrolyses next to ARG, LYS Pepsin: Hydrolyses next to PHE

Starch—1> Maltose—2> Glucose—3> Fructose Enzymes: • α -Amylase • Maltase • Glucose Isomerase

Normally: Add E + Food > Complete Rxn > Heat to inactivate E. E are never reused

New Technology: E can be physically reclaimed E bonded with insoluble support matrix

Immobilized Glucose Isomerase is used in production of high fructose corn syrup