Post on 17-Jan-2018
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ENZYMES & DIGESTION
What is occurring during digestion?
CHEMICAL REACTIONS!!!!
What is a chemical reaction?
reactant + reactant product
reactant product + product
reactant + reactant product + product
What are some other ways that we see chemical reactions represented?
We can graph the energy involved in a chemical reaction.
Ener
gy r
elea
s ed
Ene r
gy
abso
rbed
Reactants
Products
Time
What do we start with in a chemical reaction?
What do we end with in a chemical reaction?
In order for the reaction to begin, we need some ENERGY!!!!
Ener
gy r
elea
s ed
Ene r
gy
abso
rbed
Acti
vat i
on
ener
g y
reactant
Products
Time
This graph is the same reaction with an enzyme present.
Ene r
gy
abso
rbed
Ene r
gy
rele
a sed
Reactant
Products
Acti
vati
on
ener
gyTime
What was the effect of having an enzyme present for the reaction?
Ener
gy a
bsor
bed
Ener
gy r e
leas
ed Reactant
Products
Comparing Reactions Which line would represent a reaction without an enzyme present?With an enzyme present?
ENZYMES aka: Catalysts
A type of protein that speeds up chemical reactions by lowering the activation
energy.
Enzymes are specific. Enzymes work like a
lock and key. Specific enzymes
work with a specific chemical reaction.
We call the reactants of that reaction
substrates.
enzyme
substrate(reactant)
How does it work? The substrate binds to an active
site on the enzyme.Only a certain substrate fits into
the active site!
Match the substrates to their enzyme based on the “lock & key” model.
When the substrates bind, the chemical reaction occurs, and the
product is released.
What happens to the enzyme?The enzyme remains unchanged
& ready for the next set of substrates.
Enzymes work most efficiently within a certain range of temperature and pH!
Temperatures outside the range can change the shape
A pH value outside the range will cause the enzyme to change shape and be less efficient
WHY?
When an enzyme loses its shape it is said to be denatured.