any other uses? washing detergent it is a biological catalyst…
TRANSCRIPT
Exam Time!!!!
Unmotivate
d Slow
Bored
Motivated
Faster
Interested
Reward!!!!
Reward is the catalyst.
Catalyst
“Substance which can alter or speed up a chemical reaction, without itself being chemically changed at the end of the reaction”
Speed up chemical reaction Without being chemically changed
Catalyst
catalyst
Without Catalyst• Slow reaction• Needs a lot of energy to start reaction
With Catalyst
• Faster
• Needs less
energy to start
reaction
Example of Inorganic Catalyst
Potassium Chlorate (VII) Melt during heating and produce oxygen
Reaction is slow High temperature
Add catalyst manganese (IV) oxide Reaction is faster Lower temperature
No change to catalyst at the end of the
reaction.
Enzyme
Enzyme is like a wrench
Enzyme remains
unchanged.
Like wrench, it
can be reused
over and over
again.
Enzyme is
specific
E.g. wrench can
only fit bolts of
certain sizes.
Enzyme speeds up reaction in both directions.E.g. wrench can take things apart or put them together
Enzymes
Catalyse chemical reactions in living cells
Change rate of reaction
Not chemically changed
Catalyse reaction that
Build up complex substances
Break down complex substances
Biological catalysts made of proteins
Denaturation of Proteins
When denatured,
Bonds within protein molecules broken
Enzyme changes its shape
Denaturation is caused by
High temperature
Change in pH
Recap
Enzyme and Digestion
Food molecules
Large
insoluble in water
Cannot diffuse through cell membrane
Need to break down into simpler and smaller
molecules
Soluble in water
diffusible
Enzymes and Digestion
Digestive enzymes
Enzymes that help to digest food
Example
Amylase: digests starch to maltose
Maltase: digests maltose to glucose
Proteases: digest proteins to amino acids
Characteristics of Enzymes
1. Speed up chemical reactionsDefinition
Activation Energy: Energy required to start the reaction Reactants: Starting materials for reaction Products: End materials from reaction
Characteristics of Enzymes
2. Enymes are required in small amounts Remain unchanged Reused over and over again Hence only small amount is required
Characteristics of Enzymes
2. Enzymes are specific Each chemical reaction is catalysed by a
unique enzyme Lock and Key hypothesis
Characteristics of Enzymes
2. Enzymes are specificDefinition
Substrates: Substances enzymes act on Active Sites: “pockets” on enzymes where
specific substrates will fit
Characteristics of Enzymes
Heating or change of pH will change the shape of enzyme
Active site changes shape Loses its uniqueness