Download Enzyme - Northwest ISD Moodle

AGENDA – 9/11/2015
• Take out journal and pick up an exam study guide!
• Bell-Ringer: RERUN
• Enzyme Discussion and Notes
• If time, work on Exam Study Guide!
Homework:
– UNIT 1.1 Test: Wednesday, 9/16
– EXAM STUDY GUIDE!
Bell-Ringer: 9/11/15
RERUN – Toothpickase Lab
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Recall: Summarize what you did yesterday.
Explain: Explain the purpose.
Results: Describe the results and what they mean.
Uncertainties: Describe what you are still unsure about.
New: One new thing you learned.
Enzymes:
“Helper” Protein molecules
Review Macromolecules
• Proteins  Amino acids
• Carbohydrates  Sugars
– (monosaccharides, polysaccharides, glucose)
• Lipids  Fatty acids and a glycerol molecule
• Nucleic Acids  Nucleotides
Proteins
• Chains of amino acids
AA
• Many proteins are
enzymes
• Enzymes catalyze
chemical reactions
AA
AA
AA
A
A
AA
Proteins Shape
• A protein’s shape is determined by the
order that amino acids are joined in
• The shape of a protein determines its
function
Hemoglobin
antibody
enzymes
polymerase
Protein Structure
Four Levels of Structure allow for any shape
2-28
Degrees of Protein Structure
Proteins have four stages or steps to how they are built, and
end up in their final shape.
Primary Degree of Structure:
The order of amino acids in the
chain.
Secondary Degree of Structure:
Spirals and pleats
Degrees of Protein Structure
Tertiary Degree of Structure:
Big folds
Quarternary Degree of Structure:
Binding with other folded proteins
Chemical reactions of life
• Processes of life
– building molecules
• synthesis
+
– breaking down molecules
• digestion
+
Hydrolysis
• A water molecule is absorbed to break
apart a polymer. This is called
Hydrolysis.
Hydrolysis Simplified
Dehydration Synthesis
• Monomers can be linked together through the
process of Dehydration Synthesis Because Water is
Formed!
Dehydration Synthesis Simplified
Nothing works without enzymes!
• How important are enzymes?
– all chemical reactions in living organisms
require enzymes to work
enzyme
• building molecules
– synthesis enzymes
• breaking down molecules
We can’t live
without enzymes!
+
enzyme
– digestive enzymes
– enzymes speed up reactions
• “catalysts”
+
Enzymes as catalysts
• Catalyst - Speeds up
chemical reactions in
living organisms by
decreasing the energy
needed to start the
Energy
reaction (activation
energy)
Without a catalyst
With a catalyst
Time
Enzymes aren’t used up
• Enzymes are not changed by the reaction
– used only temporarily
– re-used again for the same reaction with other
molecules
– very little enzyme needed to help in many
reactions
substrate
active site
product
enzyme
Basic Enzyme Diagram
The substrates
have reacted
and changed
into the product
Enzyme is
unchanged
Active site
It’s shape that matters!
• Lock & Key model
– shape of protein
allows enzyme &
substrate to fit
– specific enzyme for
each specific
reaction
Lock and Key Model
Two substrates
Enzyme
Active site of the
enzyme
Lock and Key Model
The substrates fit like a key in a
lock
Enzyme
The active site is
like a lock
Lock and Key Model
The activation energy for these
substrates to bind together has
been lowered by the enzyme.
Chemical reaction!!!
Enzyme
In Biology when a word ends in –ase it is more
than likely it’s an enzyme.
Guess what polymers are broken down by these
enzymes and what monomers are created?
Polymer
Monomer
•Protease ________ ___________
•Sucrase ________ ___________
•Lipase ________ ___________
Enzyme vocabulary
• Enzyme
– helper protein molecule
• Substrate
– molecule that binds to the active site and what
enzymes work on
• Products
– what the enzyme helps produce from the
reaction
• Active site
– part of enzyme
that substrate
molecule fits into
Enzymes are very complex
structures whose shapes and
functions can be affected by many
factors
What factors affect enzyme
function?
pH
Temperature
pH
• Effect on rates of enzyme activity
– changes in pH changes protein shape~
Denatures
– most human enzymes = pH 6-8
• depends on where in body
• pepsin (stomach) = pH 3
• trypsin (small intestines) = pH 8
What is an acid?
• An acid is a solution that has an excess of H+
ions. It comes from the Latin word acidus that
means "sharp" or "sour".
• The more H + ions, the more acidic the
solution.
What is a base?
• A base is a
solution that has
an excess of OHions.
• Another word for
base is alkali.
• Bases are
substances that can
accept hydrogen
ions
pH Scale
• pH is a measure of how acidic or
basic a solution is.
• The pH scale ranges from 0 to 14.
• Acidic solutions have pH values
below 7
• A solution with a pH of 0 is very
acidic.
• A solution with a pH of 7 is neutral.
• Pure water has a pH of 7.
• Basic solutions have pH values above
7.
pH
intestines
trypsin
What’s
happening
here?!
reaction rate
stomach
pepsin
0
1
2
3
4
5
6
pH
7
8
9
10
11
12
13
14
Temperature
reaction rate
human
enzymes
37°
temperature
What’s
happening
here?!
Graphing enzyme activity
Optimum
Enzyme activity
Denaturation:
enzyme is ruined
Increasing
activity
20
30
40
50
Temperature (C)
60
The optimal temperature for this
enzyme is __________
Optimum
Enzyme activity
Denaturation:
enzyme is ruined
Increasing
activity
20
30
40
50
Temperature (C)
60
Order of amino acids
• Wrong order = wrong shape = can’t do its job!
chain of
amino acids
DNA
folded
protein
right shape!
folded
protein
chain of
amino acids
DNA
wrong shape!
For enzymes…
What matters?
SHAPE!