enzymes – are protein substances that are necessary for most of the chemical reactions that occur...
Post on 18-Jan-2018
215 Views
Preview:
DESCRIPTION
TRANSCRIPT
Enzymes – are protein substances that are necessary for most of the chemical reactions that occur in living cells
Enzymes affect the rate or speed of a reaction.
Usually end in –ase Derived from the name of the substrate
Ex. Maltase splits maltose into 2 glucose molecules
Enzymes that break down:proteins = proteaseslipids = lipases
Catalyst – a substance that brings about a reaction without being changed itself
Is an enzyme a catalyst?
YES
Substrate – the substance that an enzyme acts upon
Active site – the region on the surface of an enzyme where the substrate molecules attach
The active site is located on the enzyme
Enzyme-substrate complex – when the substrate molecule comes in contact with the active site of an enzyme
The enzyme-substrate complex is temporary.
The Lock and Key Model – is a theory that explains how the enzyme and substrate fit together
Each substrate can only fit into specific enzymes
Induced-Fit Model – the theory in which the enzyme slightly changes shape to allow the substrate to fit the active site of the enzyme
1. Small amounts of an enzyme can cause the reaction of large quantities of substrate.
2. Enzymes work best at certain temperatures.
3. Enzymes work best at a certain pH.4. The rate of reaction depends on the
concentrations of the enzyme and the substrate.
5. Sometimes enzymes need a coenzyme to function.
Denaturation – is when high temperatures cause the shape of the enzyme to change, so the active site no longer fits the substrate
Coenzyme – allows an enzyme to perform its function
Example of a coenzyme: a vitamin
top related