10/20/14• Have your HW out• Current science• Quiz 2.1-2.2 back• Review the ws (1st period we’ll fold too)• Real world protein example: sickle cell• Protein Intro

• Protein pennies

• Enzyme Lab• Prelab

• HW: individual lab information

Real world example!

Hemoglobin Carries Oxygen

Quaternary Structure: this is 4 “subunits” stuck together

Hemoglobin is a different shape with oxygen bound

Change of Shape is Critical• In lungs conditions cause hemoglobin to bind oxygen

•Near muscles conditions cause hemoglobin to release oxygen

What if an Amino Acid is Changed?

Sickle-Cell Hemoglobin

Just 1 Amino Acid Difference

Glutamic Acid Valine

Correct a.a is hydrophyllic

Incorrect a.a is hydrophobic!

Hydrophobic pushes in b/c “hates” water

Effe

cts

of S

ickl

e C

ell

• http://www.youtube.com/watch?v=1fN7rOwDyMQ• 4:50• http://www.dnalc.org/resources/3d/17-sickle-cell.html• 0:58

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

The Penny-Picker Enzyme

• Function of Penny-Picker:• Pick up pennies and flip them over• 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 (enzymes don’t have eyes!) 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 all 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

• Come up with a definition of denaturation.

Procedure - Trial 3: Coenzyme

• Again 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 & moving

• Record data on white board

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 approximately 50/50 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 move it to the edge of the table & flip it to tails 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

*No Need to take notes or memorize for quiz – this is just to exemplify importance of enzymes

• Where do genes come from?• The connection to venom!• https://www.youtube.com/watch?v=z9HIYjRRaDE

Pre lab- enzymes