Apple Experiment

Come down and get a slice of apple and a slice of lemon.

When you get back to your seat:1. Take a bite of one side of your apple.2. Immediately squeeze lemon juice over the apple flesh that is now

exposed from the bite.3. IMPORTANT! Don’t get lemon juice all over the apple. Make sure

that it is ONLY on the area that you just bit!4. Set the lemon aside and wipe any lemon juice off of your hands

with a napkin.5. Take another bite from the opposite side of your apple slice.6. Set your apple aside.

What Are Enzymes?What Are Enzymes?

• Enzymes are __________ ((tertiary and quaternary structures).

• An enzyme is a _________ in cellular reactions.

• A catalyst accelerates a

reaction.

EnzymesEnzymes

• Are ________ for what they will catalyze

• Are _________

• End in -_____-Sucrase-Sucrase-Lactase-Lactase-Maltase-Maltase

How do enzymes work?• Each enzyme has a unique 3-D shape, including a

surface groove called an ______ _____.

• The enzyme works by binding a specific chemical reactant (_________) to its active site, causing the substrate to become unstable and react.

• The resulting __________ is then released from the active site.

How Do Enzymes Work?How Do Enzymes Work?

Enzymes work by _______ ______ which ________ activation energy.

Enzyme-Substrate Complex

The substancesubstance (reactant) an enzymeenzyme acts on is the _________.

EnzymeSubstrate Joins

______ ___________ _____• A specific region of an enzymeenzyme molecule

which binds to the substratesubstrate.

EnzymeSubstrate

Active Site

Shape of a Protein

…A job well done

• An enzyme fits with its substrate like a ____ and ____.

EnzymeAnimation : Gary E. Kaiser http://student.ccbcmd.edu/biotutorials/proteins/enzsub.html

View : http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html

Enzymes are ____ ________ in the reactions they catalyze.

Think of them as tiny machines in manufacturing.

The more machines, the faster you get more _________.

Image:

Wine Bottling : www.morrison-chs.com/timingscrews/index.html

Wine Vats: www.lymebaywinery.co.uk/pages/about_us.htm

Formats for writing a chemical reaction.

( ________ )

_______ + ________ -----------> _________

( ________ )

__________ -----------> ______ + ______

4 levels of Protein Structure

How Do You Stop an Enzyme?

_______________

• Changing of protein shape through some form of external stress

• A denatured protein can’t carry out its function because it is a different shape!

Factors Affecting Enzyme Activity

• Temperature

• pH

• Cofactors & Coenzymes

• Inhibitors

Temperature & pH

• Think about what kind of cell or organism an enzyme may work in…

• Temperatures far above the normal range _________ enzymes (This is why very high fevers are so (This is why very high fevers are so dangerous. They can cook the body’s proteins)dangerous. They can cook the body’s proteins)

• Most enzymes work best near __________ pH (6 to 8).

Coenzymes & Cofactors

• Non-protein substances substances (zinc, iron, copper, (zinc, iron, copper, vitamins) vitamins) are sometimes needed for proper enzymatic activity.

• Coenzyme versus Cofactor: What’s the difference?

_________ more general term. Includes inorganic and organic molecules.

_________ type of Cofactor, But specifically organic molecules. Image:

EnzymeCofactor : Public domain Wiki, Ribbon-diagram showing carbonic anhydrase II. The grey sphere is the zinc cofactor in the active site.

Coenzyme : Vitamin B12

• ExampleExample::

Most _________ are coenzymes essential in helping move atoms between molecules in the formation of carbohydrates, fats, and proteins.

• Exclusively synthesized by ___________ (found primarily in meat, eggs and dairy products).

Image: VitaminB12 : NIH, Public Domain www.nlm.nih.gov/.../ency/imagepages/19516.htm

Two Types of Enzyme Two Types of Enzyme InhibitorsInhibitors

1. ___________ ____________:1. ___________ ____________: Chemicals that resembleresemble an enzyme’s enzyme’s normal substrate normal substrate and competecompete with it for the active siteactive site.

Enzyme

Competitive inhibitor

Substrate

1. Competitive inhibitors:1. Competitive inhibitors: Resembleesemble an enzyme’s normal substrate enzyme’s normal substrate and competecompete with it for the active siteactive site.

Image: Competitive Inhibition : www-biol.paisley.ac.uk/.../chapter3_2.html

Two Types of Enzyme Two Types of Enzyme InhibitorsInhibitors

_______________ ______________:_______________ ______________:

Do not enter the active siteo not enter the active site, but bind to another part bind to another part of the enzymeenzyme causing the enzymeenzyme to change its change its

shapeshape, altering the activealtering the active sitesite.

Enzyme

active site altered

NoncompetitiveInhibitorSubstrate

Enzyme InhibitorsEnzyme Inhibitors

Blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance.

Many _____ are enzyme inhibitors.

Enzymes are also used as _________ and __________.Images

Dead Bug : www.kansas.gov/help_center/user_testing.html

Prescription Drugs : www.patentdocs.us/.../08/by-kevin-e-noon.html

Featured Enzyme #1: Catecholase

• Catecholase is present in most ______ and __________.

• It is the enzyme that facilitates the ________ of cut or bruised fruits and vegetables by catalyzing the following reaction:

(______________)

_________ + _____ ----------------- _____________ colorless substrate

brown product

Featured Enzyme #1: Catecholase & Noncompetetive Inhibition

_________ juice and other acids are used to preserve color in fruit, particularly apples, by lowering the ____ and removing the copper site (cofactor)necessary for the enzyme to function.

catecholase

catechol + O2 -------------------------- polyphenol

colorless substrate brown product

Featured enzyme #2: Bromelain• Pineapple contains enzyme bromelain, which can

_______ _________.

• Jell-O is made of gelatin, a processed version of a structural protein called _________ that is found in many animals, including humans.

• Collagen big, fibrous molecule makes skin, bones, and tendons both strong and elastic.

• Gelatin you eat in Jell-O comes from the collagen in cow or pig bones, hooves, and connective tissues. (Yummie!)

• Examine 2 containers:

a. In one, cooked pineapple was used to make jello.

b. The other, uncooked pineapple was used.

Key to BlanksP2: protein, catalyst

P3: specific, reusable, ase

P4: actice site, substrate, product

P5: weakening bonds, lowers

P6: Substrate

P7: active site

P8: lock, key

P10: not consumed, product

P11: reactant, reactant, enzyme, product, reactant, enzyme, product, product

P13: denaturation

P15: denature, neutral

P16: cofactor, coenzyme

P17: vitamins, bacteria

P18: competitive inhibitors

P20: noncompetitive inhibitors

P21: drugs, pesticides, herbicides

P22: fruits, vegetables, browning, catechol, oxygen, catecholase, polyphenol

P23: lemon, pH

P24: digest protein, collagen