Today 1/28
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Using what you learned with the online
simulation and notes yesterday explain this
graph:
(i.e. what is it showing, what is it comparing, what are
the two lines, what are A and B, etc.)
https://www.youtube.com/watch?v=wp_yy
DEEC3k
Today 1/27 in journal:
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TURN IN IPHONE LAB!!!
To review for quiz 1. Name each monomer and 2.
Name the macromolecule that it would build
1.
3.
2.
4.
The “Big Picture”
DNA
Gene
Protein
Cell
Tissue/
Organ
Organism/
Trait
ENZYMES
HOW MUCH WOOD COULD A
WOOD CHUCK CHUCK IF A WOOD
CHUCK COULD CHUCK WOOD?!
Eat:
Cellulose
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Need:
Enzyme cellulase
(to break down into glucose)
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What WOULD have the ability to
digest wood and why?
What is lactose intolerance?
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Eat: Lactose
Need: Enzyme
lactase
(to break down into
glucose (and
galactose))
Intro Video…
https://www.youtube.com/watch?v=XTUm-75-PL4
What is an enzyme?

Also called a
catalyst
 Protein that speeds
up the rate of a
reaction.
 Not changed during
the reaction.
Why are enzymes important?

Decreases the amount
of energy needed
(activation energy) for a
reaction to occur.
 As a result, the reaction
happens faster.
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Simulation:
http://web.biosci.utexas.edu/psaxena/
MicrobiologyAnimations/Animations/E
nzyme-Substrate/micro_enzymesubstrate.swf
Green line is reaction without enzyme
Red line is reaction WITH enzyme.
What would happen if we did not
have enzymes or they did not
work properly?

You would DIE!
 No enzymes =
reactions happening
too slowly so body
can’t get what it
needs to survive.
How Does an Enzyme Work?

Because only certain substrates will fit
in certain enzymes they are often
compared to a LOCK & KEY MODEL
How does an Enzyme Work?

Each enzyme has a
specific shape which
causes it to bind with
specific reactants
Parts of an EnzymeSubstrate Complex:



Substrates- reactants that fit with
enzyme
Active site- site on enzyme that
substrates bind to
Products- created from
combining of substrates. This is
what leaves the enzyme
How Does an Enzyme Work?

Enzymes work one of two
ways
– Bind two reactants to make
one product (see picture on
right)
– Break bonds in large
molecule to make many
smaller ones (see picture
below)
One reactant is broken apart to make two products. Orange structure is enzyme,
green & blue parts in first part of picture are substrates.
Two reactants bind together
to make one product
What may alter enzyme
functioning?
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

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pH, salt concentration,
temperature
All will DENATURE enzyme.
Changes its shape so it no
longer accepts substrates so
can’t create products.
This would slow down/stop
reactions from happening in
body.
Ex. Frying an egg- Check out
this animation:
– http://www.sumanasinc.com/we
bcontent/animations/content/pr
oteinstructure.html
And of course… a song....
https://www.youtube.com/watch?v=NdMVRL4oaUo
Can you answer these questions about the
picture below? (Check answers on next
page.)
1.
2.
3.
4.
5.
6.
7.
8.
9.
What type of macromolecule is an enzyme?
What is another name for enzyme?
What is the enzyme term for #2?
What is the enzyme term for the site on the enzyme where the sucrose
attaches?
What is added at #3?
What is the enzyme term for the glucose & fructose created at #4?
Has the enzyme changed in this reaction?
What types of factors could denature the enzyme?
What will happen if the enzyme is denatured?
Can you answer these questions about the
picture below? ANSWERS
1.
2.
3.
4.
5.
6.
7.
8.
9.
What type of macromolecule is an enzyme? Protein
What is another name for enzyme? Catalyst
What is the enzyme term for #2? Reactant
What is the enzyme term for the site on the enzyme where the sucrose attaches?
Active Site
What is added at #3? Water (H2O)
What is the enzyme term for the glucose & fructose created at #4? Products
Has the enzyme changed in this reaction? No- has same shape so can be
reused
What types of factors could denature the enzyme? pH, temperature, salt
What will happen if the enzyme is denatured? Active site is changed so reactants can no
longer fit into enzyme so reaction can’t happen. This means you can no longer break down sucrose
to get the glucose & fructose so cells can’t absorb these glucose & fructose molecules to use them.
Cell may “starve” for these molecules.
Can you answer these questions about the
graph below? (Check answers on next page.)
This graphs shows how an enzyme
functions at different pH levels.
1.
2.
This enzyme works best at
which pH?
Would you find this enzyme
in your stomach or blood?
How do you know?
This graphs shows how an enzyme
functions at different temperatures.
1.
2.
This enzyme works best at
which temperature?
What would happen to the
reaction (enzyme activity) if
the temperature were to reach
70⁰C?
Can you answer these questions about the
graph below? ANSWERS
This graphs shows how an enzyme functions
at different pH levels.
1.
2.
This enzyme works best at which pH? pH 7
Would you find this enzyme in your stomach
or blood? Blood How do you know?
Stomach has acidic environment so would
need an enzyme that works best at an
acidic pH level.
This graphs shows how an enzyme functions at
different temperatures.
1.
This enzyme works best at which
temperature? 40⁰C
2.
What would happen to the reaction
(enzyme activity) if the temperature were
to reach 70⁰C? Enzyme would be
denatured after about 45⁰C so reaction
would stop, which means cells can’t
get what they need.
Extra Resources:
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Tutorials:
http://www.phschool.com/atschool/phbio/active_a
rt/enzyme_action/
http://www.learnerstv.com/animation/animation.php?
ani=324&cat=Biology
Simulation:
http://web.biosci.utexas.edu/psaxena/MicrobiologyAni
mations/Animations/EnzymeSubstrate/micro_enzyme-substrate.swf
Animations:http://www.kscience.co.uk/animations/ani
m_2.htm
http://highered.mheducation.com/sites/0072495855/s
tudent_view0/chapter2/animation__how_enzymes_w
ork.html