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

• N wants 3 bonds and has 2 lone pairs• N is very electronegative

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e

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- δ+

δ+

δ+

δ+

δ-

δ- δ+

δ+

δ+

δ+

δ-

2.2.III

• Lots of partial charges All non-polar bonds• Lots of H-bonds No partial charges

No H-bonds

Hydrophilic Hydrophobic

δ-δ-

δ-δ- δ+

δ+δ-

δ+

δ+δ-

What is Heat?

ENZYMESProtein Catalysts

Enzymes Are Catalysts

•Not used up in the reaction

•Help chemical reactions occur

In Chemical Equations

• Sucrose Maltose

• Sucrose + Amylase Maltose + Amylase

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 After 20s After 30s After 40s

Trial 1

Trial 2

Trial 3

Trial 4

Trial 5

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