In everyday life, we attempt to
achieve as much speed as possible.
Stairs V.S Elevator/ Lift
Hand Wash V.S Washing Machine
Knife
V.S
Blender
Things that speed things up
Chemical Reactions
A
B
X
C
Y
D
Z
So what are those that
speed up the reaction
called?
Catalyst
Definition:
A catalyst is a substance which can alter or speed
up a chemical reaction, without itself being
chemically changed at the end of the reaction.
Breakdown of Potassium Chlorate (VII)
2 KCIO3
Potassium
chlorate (VII)
2 KCIO3
Potassium
chlorate (VII)
2 KCI
heated to more
than 400 ºC
CATALYST
Manganese (IV) oxide
Gentle heating
Potassium
chloride
2 KCI
Potassium
chloride
3 O2
Oxygen
3 O2
Oxygen
Without manganese (IV) oxide
With manganese (IV) oxide
Temperature
Without manganese (IV) oxide
With manganese (IV) oxide
Rate of oxygen production
Manganese (IV) oxide is a catalyst
Catalysts
Inorganic Catalysts
E.g. manganese (IV) oxide
Organic / Biological
Catalysts
So what are organic/
biological catalysts?
Enzymes
What are Enzymes
• Biological catalysts
• Made in the cytoplasm under instruction from
genes which are located on the chromosomes
in the nucleus.
• Made of Protein
What are Enzymes
Definition:
Enzymes are biological catalysts made of
protein which speed up the rate of chemical
reactions without themselves being changed
at the end of the reactions.
So what chemical reactions
do the enzymes catalyse?
Chemical Reactions Enzyme Catalyse
• Build up substances (Anabolic Reaction)
Enzyme
A
B
C
• Break down substances (Catabolic Reaction)
Enzyme
X
Y
Z
Chemical Reactions Enzyme Catalyse
• Reversible Reactions
Enzyme
A
B
C
D
Build up Substances (Anabolic Reactions)
Enzyme
A
B
C
Definition:
Synthesis of complex molecules from
simpler ones.
Build up Substances (Anabolic Reactions)
A
Enzyme
C
B
Examples
Building Protein from Amino Acids
Amino Acids
Polypeptides
Building glycogen from glucose.
Glucose
Glycogen
Protein
Breakdown of Substances
(Catabolic Reactions)
X
Enzyme
Y
Z
Definition:
Breaking down of large, complex molecules
into simpler ones.
Breakdown of Substances
(Catabolic Reactions)
X
Enzyme
Z
Y
Examples
Breakdown of Glucose during Respiration
Breakdown of poisonous substances to harmless substances (Detoxification)
Hydrogen peroxide
(poisonous substance)
Catalase
Water
+
Oxygen
(non-poisonous substances)
Chemical Reactions Enzyme Catalyse
• Reversible Reactions
Enzyme
A
B
C
D
Definition:
Reactions that proceed in the forward or
backward reaction.
Chemical Reactions Enzyme Catalyse
• Reversible Reactions
Enzyme
A
B
C
D
With so much chemical reactions
and enzymes around the world, how
do we differentiate them?
ENZYME
Now, how do we name the
Enzymes?
Naming of Enzymes
• At first, they were named after
scientists that discover them.
• Enzymes are named after the
substrate on which they act and with
a suffix “-ase”.
Naming of Enzymes
• According to Type of Nutrient
(Carbohydrate, Proteins, Fats)
• Specific names for each type of
nutrient
Carbohydrate
ase
Naming of Enzymes
Specific Carbohydrate
(names ending with “ose”)
Will have their ending of “ose” being
replaced with “ase”.
ase
Maltose
Substrate Name +
-ase
ase
Cellulose
Starchase
Amylase
ase
Protein
Substrate Name +
-ase
Naming of Enzymes
Specific Protein
Names will have “in” as endings.
Pepsin
Renin
Proteins to polypeptides
Polypeptides to amino acids
ase
Lipid
Substrate Name + -ase
Activity:
What type of nutrient
does the enzyme
target?
Maltase
Renin
Amylase
Lipase
Erepsin
What we learn today.
• Definition of Catalysts
• Example of a Catalytic Reaction
• Types of Catalysts
• Definition of Enzymes
• Reactions Catalysed by Enzymes
• Naming of Enzymes