topic 3.6 enzymes. define enzyme and active site enzyme – protein catalysts that speed up the...
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Topic 3.6 Enzymes
Define enzyme and active site Enzyme – protein catalysts that speed up the
rate of chemical reactions Active Site - part of an enzyme where
substrates bind and undergo a chemical reaction
EXPLAIN the effects of temperature, pH and substrate concentration on enzyme activity
Define denaturation a process in which proteins or nucleic acids
lose the tertiary structure and secondary structure which is present in their normal state, by application of some external stress or compound such as a strong acid or base, a concentrated inorganic salt, or heat.
Loss of structure = loss of function
Introducing Enzymes They are catalysts so the make reactions easier
This increases productivity and yield Globular proteins As catalysts they are not consumed by the reaction
The may be used over and over again Enzymes show specificity to the reaction they
control Enzymes are sensitive to their environment so they
can be controlled by adjusting the temperature, the pH or the substrate concentration
Enzyme-Substrate Specificity
Enzymes have been used in biotechnology for millennia
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Lactase Lactase is used to remove the sugar lactose
from milk and other dairy products
Lactose intolerance Some people are intolerant of lactose in milk they
cannot digest it The lactose remains in the digestive system and is
fermented by bacteria The result is nausea, cramps, bloating, gas, and
diarrhea occurring within 4h of consuming milk products
The treatment includes taking a tablet of lactase enzyme with a meal
The lactase digests the lactose in the food A special lactose free diet may be necessary
Source
Lactase enzyme (-galactosidase) is extracted from fungi such as Aspergillus oryzae
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ReactionSubstrate: Lactose
Lactose + H2O-galactosidase
Glucose + Galactose
This is a hydrolysis reaction
Advantages Lactose intolerant patients can
digest their food Lactose free products can be
prepared for special diets Lactase is used to hydrolyse
lactose in ice cream into glucose and galactose to give it a sweeter flavour
Stoney Creek Dairy