Lecture 9 - Part 2 Flashcards
What contributes to the decrease in rim rate over time?
- ( 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
What is salts relationship with enzymes?
Required by some “E”
Denatures some “E”
What is an oxidoreductase?
Oxidoreductase
Transfers H+ or electrons
What is hydrolase?
Uses water to break bond
What is a lyase?
Adds or removes groups to / from double bond
What is a ligase?
Links two molecules
What is an isomerase?
Catalyzes geometric changes
-Glucose isomersae converts glucose to fructose
What is alpha amylase?
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
What is invertase?
Enzymes used in food processing
Invertase (Sucrase)
Sucrose Glucose + Fructose
-Makes invert sugars
Candy Industry
What is beta galactosidase?
Enzyme used in food processing
(Lactase)
Lactose > Galactose + Glucose
Some people can lac this enzyme ini their intestines
What is cellulase?
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
Where can we use cellulase?
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
What is pectinate and pectin esterase?
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
What is pectinases?
Hydrolyze Polymer Chain which results in:
Cloud Formation in the fruit juice
Then the cloud is Filtered Out
Clarify Fruit Juices (Apple)/Wine
What does pectin esterase break off?
Pectin Esterase (breaks off –OCH3 group)
Cloud Formation> Filter Out Cloud > Clear Juice/Wine
What is phenolase?
Enzymes used in food processing
Phenolic into O-Quinone (Brown Colour)
Desirable? Tea, Coffee
Undesirable? Fresh Fruits (Apples…)
What is glucose oxidase?
β-D-Glucose + 02 > D–Glucono-δ-Lactone + H202
Hydrogen peroxide and add the enzyme so we convert it into water
What is a catalase?
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
What does lipase do?
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 )
What is a proteolytic enzymes?
Require Specific A.A > to break the peptide bond
Trypsin: Hydrolyses next to ARG, LYS
Pepsin: Hydrolyses next to PHE
How are enzymes used in making high fructose corn syrup?
Starch—1> Maltose—2> Glucose—3> Fructose
Enzymes:
- α -Amylase
- Maltase
- Glucose Isomerase
How do immobilized enzymes work?
Normally:
Add E + Food > Complete Rxn > Heat to inactivate E.
E are never reused
What does new technology allow for immobilized enzymes?
New Technology:
E can be physically reclaimed
E bonded with insoluble support matrix
What is immobilized in the production of high fructose corn syrup?
Immobilized Glucose Isomerase is used in production of high fructose corn syrup
What are the characteristics of high fructose corn syrup?
↑ Sweetness
↓Crystallization
↓ Viscosity
Where do natural enzyme inhibitors occur naturally?
Soybeans
8 different “proteinase” inhibitors
Kunitz inhibitor: InhibitsTrypsin
Stable pH 1-12
T <30oC
80-90oC > Denaturation
What other vegetable has naturally occurring enzyme inhibitors?
Potatoes
Invertase inhibitor
During growth
[ inhibitor]» [invertase]
During storage
[invertase] ↑ but still
[inhibitor]»_space; [invertase]
During cold storage
[invertase] > [inhibitor]
