Textbook pages: 78-81 Figure 5-5 on pg. 80Textbook pages: 78-81 Figure 5-5 on pg. 80

You will be responsible for all definitions on pages 1 & 5 of You will be responsible for all definitions on pages 1 & 5 of the enzyme packet, and should be able to interpret the the enzyme packet, and should be able to interpret the graphs on Page 3 of the packet.graphs on Page 3 of the packet.

Enzymes: Enzymes: Proteins that are used for chemical reactions

• Enzymes can either break up or put together substrates

• Enzymes are specific – only work on certain substances.

• Enzymes are catalysts that react on substrates

• Enzymes are NOT CHANGED in the reaction

Definitions:Definitions:

ProteinsProteins: Biochemical : Biochemical compounds (macromolecules) compounds (macromolecules) made up of long polymer chains made up of long polymer chains of amino acids linked togetherof amino acids linked together

CatalystCatalyst: A substance that : A substance that causes a reaction to occur but causes a reaction to occur but does not get changed itselfdoes not get changed itself

Definitions:Definitions:

SubstrateSubstrate: A substance that the : A substance that the catalyst (enzyme) acts oncatalyst (enzyme) acts on

Ex) Lactose = milk sugar (substrate)Ex) Lactose = milk sugar (substrate)

Lactase = breaks down lactose (enzyme)Lactase = breaks down lactose (enzyme)

Active SiteActive Site: The specific : The specific region of the enzyme that region of the enzyme that combines with the substratecombines with the substrate

Lock and KeyLock and Key::

The lock is the The lock is the enzyme and the enzyme and the

key is the key is the substrate. substrate.

Only the Only the correctly sized correctly sized key (substrate) key (substrate) fits into the key fits into the key hole (active site) hole (active site) of the lock of the lock (enzyme).(enzyme).

Lactose is a 2-unit sugar. Lactase breaks it into 2 individual sugars: glucose and galactose.Can it break down sucrose as well? Why or why not?

Factors that affect the Factors that affect the rate of Enzyme Action:rate of Enzyme Action:

Enzymes work best at Enzymes work best at certain:certain:–TemperaturesTemperatures–pH pH –ConcentrationsConcentrations(See Graphs- Page 3 of Enzyme (See Graphs- Page 3 of Enzyme

Packet)Packet)

Factors that affect the Factors that affect the rate of Enzyme Action:rate of Enzyme Action:

Temperature: There is an optimum Temperature: There is an optimum (best) temperature that each enzyme (best) temperature that each enzyme works in . Increase temperature, works in . Increase temperature, increase molecule movement, increase molecule movement, increase rate of the reaction. increase rate of the reaction.

Temperature too LOW, decrease the Temperature too LOW, decrease the effect of the enzymeeffect of the enzyme

Temperature too HIGH- Protein Temperature too HIGH- Protein Denatures (breaks down/changes Denatures (breaks down/changes shape)- the enzyme will not work.shape)- the enzyme will not work.

Denatured EnzymeDenatured Enzyme

Factors that affect the Factors that affect the rate of Enzyme Action:rate of Enzyme Action:

pH: Enzymes work best at different pH: Enzymes work best at different pH levels depending on where they pH levels depending on where they are. Page 4- Enzyme Packet: Relative are. Page 4- Enzyme Packet: Relative Rate of Enzyme Action.Rate of Enzyme Action.

pH Scale?pH Scale? Acidic = 0 – 6.9 Basic = 7.1 – 14Acidic = 0 – 6.9 Basic = 7.1 – 14 #3- Enzyme A- pH of the stomach?#3- Enzyme A- pH of the stomach? #4- Enzyme B- pH of the intestine?#4- Enzyme B- pH of the intestine?

Factors that affect the Factors that affect the rate of Enzyme Action:rate of Enzyme Action:

Concentration: Concentration: Increasing the amount of enzyme Increasing the amount of enzyme will increase the rate of reaction, but will increase the rate of reaction, but it will eventually level off- why?it will eventually level off- why?For the same reason, increasing the For the same reason, increasing the substrate concentration will increase substrate concentration will increase the rate of reaction, but it will the rate of reaction, but it will eventually level off.eventually level off.

SEE ALL GRAPHS ON PAGE 3 of the Enzyme Packet

Activation EnergyActivation Energy

The energy needed to start a chemical The energy needed to start a chemical reaction.reaction.

Similar to rolling a boulder downhill, it is Similar to rolling a boulder downhill, it is the chemical ‘push’ that gets a chemical the chemical ‘push’ that gets a chemical reaction going.reaction going.

Enzymes lower the activation energy Enzymes lower the activation energy needed for chemical reactions. Less needed for chemical reactions. Less energy needed to start the reaction, can energy needed to start the reaction, can occur at lower temperatures.occur at lower temperatures.

Activation EnergyActivation EnergyEndothermic: BuildingEndothermic: Building

Activation EnergyActivation EnergyExothermic: Exothermic: BreakdownBreakdown

Enzyme AnimationEnzyme Animation

http://www.biotopics.co.uk/other/hienz.html

http://www.kscience.co.uk/animations/anim_2.htm

How Enzymes WorkHow Enzymes Work The The active siteactive site (location on the enzyme (location on the enzyme

where the substrate fits and the reaction where the substrate fits and the reaction takes place) on the enzyme attaches to a takes place) on the enzyme attaches to a substrate molecule substrate molecule

While attached to the substrate, the enzyme While attached to the substrate, the enzyme either breaks or makes a bond, resulting a either breaks or makes a bond, resulting a change to the substratechange to the substrate

Ex) Carbohydrate broken into sugarsEx) Carbohydrate broken into sugars

Amino acids bonded to make proteinAmino acids bonded to make protein

The enzyme is not changed during the The enzyme is not changed during the reaction and is free to break-down more reaction and is free to break-down more substratessubstrates

CAPT LAB: ENZYMES CAPT LAB: ENZYMES

Comparing the effectiveness of cellulase Comparing the effectiveness of cellulase and pectinase in making juice.and pectinase in making juice.

You will investigate which enzyme or You will investigate which enzyme or combination of enzymes will remove combination of enzymes will remove more juice during the process of making more juice during the process of making apple juice from applesauce .apple juice from applesauce .

Once you complete the lab, you will Once you complete the lab, you will evaluate which enzyme will be the most evaluate which enzyme will be the most cost effective plan to use in juice cost effective plan to use in juice production.production.

CELLULOSECELLULOSE

Large carbohydrateLarge carbohydrate Composes the cell walls of plantsComposes the cell walls of plants Tough and fibrous – provides Tough and fibrous – provides

structure to plantsstructure to plants

CELLULASECELLULASE

The enzyme that breaks down The enzyme that breaks down cellulosecellulose

The optimum pH generally lies The optimum pH generally lies between 4 and 5 between 4 and 5

PectinPectin

Large carbohydrate found in plant Large carbohydrate found in plant cell wallscell walls

Sticky substance used to bind Sticky substance used to bind plant cell walls to each other and plant cell walls to each other and hold cellulose in placehold cellulose in place

PectinasePectinase

Enzyme that breaks down the Enzyme that breaks down the pectin in plant cellspectin in plant cells

Used to produce fruit juice and Used to produce fruit juice and winewine

Optimum pH is 4-5Optimum pH is 4-5

CAPT Lab: CAPT Lab: Cellulase v. PectinaseCellulase v. Pectinase

Enzymes?Enzymes?Pectinase and CellulasePectinase and Cellulase

Substrates?Substrates?Apple SauceApple Sauce

CAPT LAB: PurposeCAPT LAB: Purpose

To determine which enzyme, or To determine which enzyme, or combination of enzymes, will combination of enzymes, will produce the most juice for the produce the most juice for the least costleast cost