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 Atomic mass is P + N # 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 ee e e e ee

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?

Enzymes Protein Catalysts

Not used up in the reaction Help chemical reactions occur Enzymes Are Catalysts Not used up in the reaction Help chemical reactions occur

In Chemical Equations Sucrose Maltose Amylase Sucrose 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

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