are organic catalysts produced by living organisms.
ENZYMES
Enzymes are_____that functions as biological catalysts
proteins
a substance that speeds up a chemical reaction and is not changed by the reaction)
Catalyst
usually end in “
ase “ or “ in “
discovered in ___ in yeasts
1900
in human cells
40,000
controls almost every metabolic reaction in living organism.
ENZYMES
PROPERTIES
Enzymes are
colloids
Soluble in water and dilute alcohol but are precipitated by
concentrated alcohol.
Most enzymes act best at temperatures between
35 and 400C
Certain heavy metals, ____retard the enzyme’s activity
formaldehyde and free iodine
Each enzyme speeds up only
1 kind of reaction
Possess an active site such as a ____ in the molecule onto which other substrate molecules can bind to form enzyme-substrate complex.
cleft
their presence does not affect the nature and properties of the
end product
Sensitive to change in
pH, temp, & substance concentrate
FACTORS THAT AFFECT ENZYME ACTIVITY
TEMPERATURE
pH
ENZYME CONCENTRATION
SUBSTRATE CONCENTRATION
The specific action of an enzyme with a single substrate can be explained using a
Lock and Key analogy
first postulated in 1894 by
Emil Fischer.
In this analogy, the lock is the enzyme and the key is the substrate. Only the correctly sized ____fits into the____ of the lock (enzyme).
key (substrate), key hole (active site), lock (enzyme).
The basic mechanism by which enzymes catalyze chemical reactions begins with the binding of the____ (or substrates) to the active site on the enzyme.
substrate