Agenda
• Briefly review Quiz
• Briefly review worksheet
• Current Event
• Intro to Enzymes and Penny-Picker
• Enzyme Catalysis Pre-Lab
• HW: Finish Pre-Lab (write individual preliminary
procedure)
• Gone Thursday? – must come Thursday morning to
turn in your preliminary procedure and take exit slip
2.1.I
• 2 pts per question
• Atomic # is
• # of protons
• What determines the element
• If neutral # of protons = # of electrons
• NOT necessarily # of neutrons
• Atomic mass is P + N
• Atomic Charge is P – e (neutral if P=e)
2.1.II
• 0.5 pts per part
• 19Protons = K = potassium
• Mass = protons + neutrons = 19 + 20 = 39
• I didn’t take points off but 39.1 is NOT correct since this atom has
20 neutrons. 39.1 would be the average for all atoms
• 19P, 18e- = charge of 1+
• Explain any of the above for 0.5 or WHY K forms 1+ ion is
fine
2.1.III
e
e
e
e
ee
e
e
e
e
ee
e
• N wants 3 bonds and has 2 lone pairs
• N is very electronegative
2.2.I
• Polar (unequal) covalent (sharing)
• Non-polar covalent = equal sharing
due to equal electronegativity
• Ionic bonds form between ions
• Ions can form when electrons are
stripped
2.2.II
δ+
δδ+
δ+
δ-
δ+
δ+
δ-
δ+
δ+
δδ+
2.2.III
• Lots of partial charges
• Lots of H-bonds
δ-
δ+
δ-
δ-
δ-
All non-polar bonds
No partial charges
No H-bonds
δ+
δ+
δ+
δδ-
Hydrophilic
Hydrophobic
What is Heat?
ENZYMES
Protein Catalysts
Enzymes Are Catalysts
• Not used up in
the reaction
• Help chemical
reactions
occur
In Chemical Equations
• Sucrose
Amylase
Maltose
• Sucrose + Amylase  Maltose + Amylase
Enzymes are Proteins
• Bonds with substrates (reactants) in
active site
Enzymes Are Specific
• Have complementary structures
allowing them to bond with only
certain substrates
Realistic Diagram
Enzymes Help Break Bonds
All Chemical Reactions Involve Breaking
Bonds in Reactants
• Allows new bonds to form instead
Enzyme-Substrate Reactions
• Both are molecules just floating around in
solution
• When they happen to come in contact with each
other, they can form temporary bonds
The Penny-Picker Enzyme
• Function of Penny-Picker:
• Pick up pennies and flip them over and move them to a
corner of the desk
• No looking! Enzymes have no eyes!
• The pennies represent a toxic byproduct of cellular
processes that must be converted to a safer form
• Active site:
• Specific to ONE substrate. What’s the substrate?
• Pennies
• Only holds ONE penny at a time
Data Table
• On your whiteboard make the following table:
After 10s
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
After 20s
After 30s
After 40s
Procedure - Trial 1: Baseline
• Spread out pennies on table HEADS side up
• Without looking grab pennies and flip them over, putting
them in the corner of your table
• One person flips pennies for FOUR 10-second intervals
without looking; one person times and counts
• Record data on your whiteboard.
• DO NOT REPLACE THE PENNIES BETWEEN TIME
INTERVALS
Procedure - Trial 2: Denaturation
• Spread out pennies on table HEADS side up
• Repeat procedure for flipping pennies in four 10-second
intervals
• THIS TIME:
• Hand used to flip pennies gets taped around all four fingers (partial
denaturation)
• Record data on white board
Procedure - Trial 3: Coenzyme
• Spread out pennies on table HEADS side up
• Repeat procedure for flipping pennies in four 10-second
intervals
• THIS TIME:
• Enzyme has the help of a teammate, representing a coenzyme
• Coenzyme picks up pennies and hands them to enzyme for flipping
• Record data on whiteboard
Co-Enzymes
*No Need to take notes or memorize for quiz – this is just to exemplify
importance of enzymes
Procedure - Trial 4: Competitive Inhibitors
• Spread out pennies on table with a mix of HEADS and TAILS
up
• TAILS pennies represent competitive inhibitors. Molecules
that have a similar shape and bind to the active site, but
cannot be broken down.
• Repeat procedure for flipping pennies in four 10-second
intervals
• THIS TIME:
• If your partner picks up a HEADS penny they flip it and move it to the
corner and you count it
• If your partner picks up a TAILS penny you must stop them and tell
them to put it back down
• Record data on whiteboard
Procedure – Trial 5: Non-Competitive
Inhibition
• Spread the pennies out as before
• Make your hand into a fist
• Tape it closed
• This represents an inhibitor that binds to the enzyme and
permanently alters its shape
• Try to pick up pennies for each of the 4 intervals
• Fail to pick up pennies and die
Non-Competitive Inhibitors and Venoms
Enzymes Lab
• Will be run next Monday
• Today – Prelab, Individually write preliminary
procedures (S.P. 0.1)
• Thursday – As a group write one final
procedure
• Monday – Conduct experiment
• Goal: Examine how environmental factors
affect the rate of an enzyme catalyzed reaction
Pre-Lab
• Discuss each question as a group (except
last 2 to be done individually)
• Get approval from Mr. Mahon before
proceeding to the next question
Preliminary Procedure
• Will be evaluated for S.P. 0.1
• Think about what makes a strong experiment
as discussed in unit 1
• While you should all be designing an
experiment to assess the same hypothesis –
each person’s procedure should be
individual
• Thursday you will take the best aspects of
each person’s procedure to make your group
procedure