3.16 Part II
Review Proteins
Enzyme Notes (Lecture 10)
Enzyme Video
Enzyme Handouts
Lab # 8 Enzymes
Break
Protein Review
Formation of a Polypeptide
Amino Acid + Amino Acid + … 
Polypeptide
Formation of a Polypeptide
Serine
Valine
Tyrosine
3 H2O
Cysteine
Formation of a Polypeptide
Serine
Valine
Tyrosine
3 H2O
Cysteine
Formation of a Polypeptide
A Short Polypeptide
Peptide Bond
Formation of a Protein
Polypeptide
Enzymes are Catalysts
Catalysts: substances that speed
up chemical reactions without
being affected by the reactions
themselves.
Enzyme: a protein that increases
the rate of reactions by lowering
the activation energy.
Enzymes lower AE
Activation
Energy:
the amount
of energy
needed to
start a
chemical
reaction
Enzymes lower AE
Enzyme-Substrate Specificity
Substrate: molecule on which an
enzyme acts
An enzyme binds to a substrate and
stresses the bonds of that molecule in
a way that makes a reaction more
likely to occur.
The key to an enzyme’s activity is
its shape.
Active Site: location on an enzyme
where the substrate binds
Each substrate can only bind to one
enzyme.
Enzyme-Substrate Specificity
Enzyme-Substrate Specificity
Enzymes can
be reused!
Effect of Temperature on Enzymes
Effect of pH on Enzymes
Denaturation
Enzymes become denatured
when exposed to high
temperatures or adverse pH.
How do enzymes become
denatured?
Effect of [Enzyme] on
Enzymatic Reactions
Effect of [Substrate] on
Enzymatic Reactions
Lab 9: Enzymes
Exercise I: Enzyme Quanity & pH
Group 1: pH 4,5,6
Group 2: pH 7,8,9
Share Data
Exercise 2: Effects of
Temperature on Enzyme Activity
Both Groups