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 _sp---______ for what they will catalyze

Are ___re---______

Usually end in -_____--SucraseSucrase--LactaseLactase--MaltaseMaltase

How do enzymes work?

Each enzyme has a unique 3-D shape, including a surface groove called an _A_____ __S___.

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

The resulting _P_________ is then released from the active site.

How do enzymes work?How do enzymes work?

Enzymes work by _____ Weakening bonds __ which __ Loweringwhich __ Lowering

______ activation energy.

Enzyme-Substrate Complex

The reactant an enzymeenzyme acts on is specifically called the __S_______.

EnzymeSubstrate Joins

____AcitiveAcitive Site____Site____

A specific region of an enzymeenzyme molecule which binds

to the substratesubstrate.

Active Site

EnzymeSubstrate

Shape of a Protein

An enzyme fits with its with its substrate like a _L___ and _K___.

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 Not consumedin the reactions they catalyze.

Think of them as tiny machines in manufacturing.

The more machines, the faster the accumulation of --- Product.

Image: Wine Bottling : www.morrison-chs.com/timingscrews/index.htmlWine Vats: www.lymebaywinery.co.uk/pages/about_us.htm

Formats for writing a chemical reaction.

( ________ )

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

( ________ )

__________ -----------> ________ ________

One or more of the reactants in an enzymatic reaction is the substrate, the reactant(s) that specifically interacts with the enzyme.

4 levels of Protein Structure

How Do You Stop an Enzyme?

_____ Denaturation_________

Irreversible egg protein denaturation caused by high temperature (while cooking it).

_____ Denaturation_________

Alteration of a protein shape through some form of external stress

Denatured protein cant carry out its cellular function .

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 dangerous. (This is why very high fevers are so dangerous. They can cook the bodys proteins)They can cook the bodys proteins)

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

Coenzymes & Cofactors

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

Coenzyme versus Cofactor: Whats the dif?Whats the dif?

___Cofactor_____ more general term. Includes inorganic and organic molecules.

__Coenzyme___ 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 __ Vitamins______ are coenzymes essential in helping move atoms between molecules in the formation of carbohydrates, fats, and carbohydrates, fats, and proteins.

Exclusively synthesized by _Bacteria____ (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 InhibitorsTwo Types of Enzyme Inhibitors

1. _1. _ Competitive inhibition_________:_________:Chemicals that resembleresemble an enzymes enzymes normal substrate normal substrate and competecompete with it for the active siteactive site.the active siteactive site.

Enzyme

Competitive inhibitor

Substrate

1. Competitive inhibitors:1. Competitive inhibitors:Resembleesemble an enzymes normal substrate enzymes normal substrate and competecompetewith it for the active siteactive site.

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

Two Types of Enzyme InhibitorsTwo Types of Enzyme Inhibitors

________ Non-competative inhibition___:___:Do not enter the active siteo not enter the active site, but bind to another bind to another part part of the enzymeenzyme causing the enzymeenzyme to change change

its shapeits shape, altering the activealtering the active sitesite.

Enzyme

active sitealtered

NoncompetitiveInhibitorSubstrate

Enzyme InhibitorsEnzyme Inhibitors

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

Many __ Drugs__ are Many __ Drugs__ are enzyme inhibitors.

Enzyme inhibitors are also used as _ Herbicides and pesticides_____.ImagesDead Bug : www.kansas.gov/help_center/user_testing.htmlPrescription Drugs : www.patentdocs.us/.../08/by-kevin-e-noon.html

Featured Enzyme #1: Catecholase

Catecholase is present in most Fruits and vegetables

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

(catecholase)Catechol + oxygen ----------------- __ polyphenol __colorless substrate brown product

Featured Enzyme #1: Catecholase & Noncompetetive Inhibition

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

catecholase

catechol + O2 -------------------------- polyphenolcolorless substrate brown product

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

Jell-O is made of gelatin, a processed version of a structural protein called _collagen

___collagen_ that is found in many animals, including humans. 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.

Not Yummie!)--------Infact----------???

Apple Experiment

Get an apple and a slice of lemon.

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

exposed from the bite.3. IMPORTANT! Dont 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.6. Set your apple aside.