Download Enzyme!

Welcome to Class!
10-30 and 10-1
Complete the following:
 Biomolecules 2-D Lab due
 New entry “Role of Enzymes and Factors affect
Enzymes”
Agenda
 Lecture notes on Enzymes
 Concept Maps
 Homefun:
 Study for your test on Monday Oct 5 and Tuesday Oct
6
Chemical Reactions and Enzymes
Chemical Reactions
A chemical reaction changes one set of chemicals into
another.
reactants
product
reactant
products
Energy in Reactions
Chemical reactions that release energy occur spontaneously.
Chemical reactions that absorb energy require a source of energy.
Which reaction occurs spontaneously?
Activation Energy
Activation Energy
Enzymes
Enzymes lower activation energy and speed up chemical
reactions in cells.
Enzymes in the Body
Carbonic anhydrase speeds up this reaction by a factor of 10
million.
The Enzyme-Substrate Complex
Substrates
Product
Active Site
The active site of the enzyme and the substrate have
complimentary shapes.
Substrate
Enzyme
Active Site
The active site of the enzyme and the substrate have
complimentary shapes.
Enzyme! The Play
Develop a short play or
demonstration that
illustrates how enzymes
catalyze reactions.
Flow of energy through life
•
s2
Life is built on chemical reactions
s3
Chemical reactions of life
•
Processes of life
–
building molecules
•
–
synthesis
breaking down molecules
•
digestion
+
+
Nothing works without enzymes!
•
How important are enzymes?
– all chemical reactions in living organisms require enzymes to work
• building molecules
– synthesis enzymes
• breaking down molecules
enzyme
– digestive enzymes
– enzymes speed up reactions
We can’t live
without enzymes!
+
enzyme
+
s4
Enzymes are proteins
•
Each enzyme is the specific helper to
a specific reaction
– each enzyme needs to be the right shape for the job
– enzymes are named for the reaction
they help
• sucrase breaks down sucrose
• proteases breakdown proteins
• lipases breakdown lipids
• DNA polymerase builds DNA
Oh, I get it!
They end
in -ase
s6
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
Enzyme vocabulary
•
Enzyme
– helper molecule
•
Substrate
– molecule that enzymes work on
•
Enzyme-substrate complex
– enzyme & molecule temporarily joined
•
Active site
– part of enzyme
that substrate
molecule fits into
s10
What affects enzyme action
• Correct protein structure
– correct order of amino acids
– why? enzyme has to be right shape
• Temperature
– why? enzyme has to be right shape
• pH (acids & bases)
– why? enzyme has to be right shape
Metabolic
A
enzyme 1
B
Notice that C can produce either D or F.
This substrate has two different enzymes
Pathways
that work on it.
enzyme 2
C
enzyme 3
enzyme 5
Enzymes are very specific. In this case
enzyme 1 will catalyze the conversion of
A to B only.
19
D
F
enzyme 4
E
An anabolic reaction
Energy
Catabolic and Anabolic
Reactions
ATP
ADP + Pi
Energy
A catabolic reaction
Menu
More about Enzymes:
What Affects Enzymes
Regents Biology
What affects how well an enzyme
works?
• Correct protein structure
– correct order of amino acids
– why? enzyme has to be right shape
• Temperature
– why? enzyme has to be right shape
• pH
– why? enzyme has to be right shape
Enzyme concentration
•
Effect on rates of enzyme activity
– as increase amount of enzyme = increases how fast
the reaction happens
• more enzymes = more frequently they collide with
substrate
Enzyme concentration
reaction rate
What’s
happening
here?!
amount of enzyme
Substrate concentration
reaction rate
What’s
happening
here?!
amount of substrate
s17
Temperature
reaction rate
What’s
happening
here?!
37°
temperature
Temperature
• Effect on rates of enzyme activity
– Optimum temperature
• greatest number of collisions between
enzyme & substrate
• human enzymes = 35°- 40°C (body temp
= 37°C)
– Raise temperature
• denature protein = unfold = lose shape
– Lower temperature T°
• molecules move slower
• decrease collisions
s19
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
pH
• Effect on rates of enzyme activity
– pH changes protein shape
– most human enzymes = pH 6-8
• depends on where in body
• pepsin (stomach) = pH 3
• trypsin (small intestines) = pH 8
s21
For enzymes…
What matters?
SHAPE!
Regents Biology