AMAZING ENZYMESAMAZING ENZYMES

Just What are Enzymes?• Enzymes are protein molecules that are manufactured by all plant and

animal cells. All cells require enzymes to survive and function.• Enzymes are catalysts, which means that they speed up chemical reactions,

but are not changed by the reaction. For example, digestive enzymes cause food that we eat to be broken down much faster than would occur without them, but they are not broken down in the reaction they are speeding up.

• Unfortunately, because of improper diet and the fact that heat destroys many enzymes, you may not be receiving all you need to properly support your overall health.

• Plus Life Plus uses Cold Processing in it's manufacturing. Cold processing is used to maximize and preserve enzyme activity.

• For additional enzymes support try SomaZyme. The enzymes in Somazyme naturally and nutritionally support a youthful body, provide antioxidant support, as well as support healthy pancreas and immune system function.*

• Virtually everyone of the Life Plus products is formulated with the exclusive PhytoZyme base of phytonutrients consisting of concentrations of herbs, fruits, vegetables and plant enzymes.

WHAT ARE ENZYMES?

• Enzymes are protein catalyst which speed up or slow down a chemical reaction without itself being consumed by the reaction.

• They remain unchanged

Enzyme Action

Learning objective: to describe different models forenzyme action and to investigate factors which control the rate of an enzyme reaction

14th October

More free powerpoints at www.worldofteaching.com

Lock and Key

Lock and Key

However certain substances can bind to the enzyme at sites other than theActive site and modify its activity (inhibitors/co-factors)

Idea that the enzyme is flexible

Induced Fit

Enzyme reactions

enzyme + substrate enzyme-substrate complex

Enzyme reactions

enzyme + substrate enzyme-substrate complex

E +S ES

Enzyme reactions

enzyme + productenzyme-substrate complex

E +PES

enzyme + substrate enzyme-substrate complex

E +S ES

Enzyme activity

How fast an enzyme is workingRate of Reaction

Enzyme activity

How fast an enzyme is workingRate of Reaction

Rate of Reaction = Amount of substrate changed (or amount product formed) in a given period of time.

Enzyme activity

Five Variables

Enzyme activity

Five Variables

Temperature

pH

Enzyme Concentration

Substrate Concentration

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Enzyme activity

Variable you are looking at

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Temperature

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Temperature

0 20 30 5010 40 60

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0 20 30 5010 40 60

40oC - denatures

5- 40oC Increase in Activity

<5oC - inactive

Effect of heat on enzyme activtyIf you heat the protein above its optimal temperature

bonds break meaning the protein loses it secondary and tertiary structure

Effect of heat on enzyme activty

Denaturing the protein

Effect of heat on enzyme activty

Denaturing the protein

ACTIVE SITE CHANGES SHAPE SO SUBSTRATE NO LONGER FITS

Even if temperature lowered – enzyme can’t regain its correct shape

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pH

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1 3 42 5 6 7 8 9

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Narrow pH optima

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Narrow pH optima

WHY?

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Narrow pH optima

Disrupt Ionic bonds - Structure

Effect charged residues at activesite

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Enzyme Concentration

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Enzyme Concentration

Enzyme Concentration

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Substrate Concentration

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Substrate Concentration

Substrate Concentration

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Substrate Concentration

Substrate Concentration

Active sites full- maximum turnover

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Substrate Concentration

Substrate Concentration

Active sites full- maximum turnover

ENERGY CHANGES

• When chemical reactions take place bonds are broken and formed.

• Breaking bonds require energy it is endergonic.

• If the energy is in the form of heat it is Endothermic

ENERGY CHANGES

• Froming bonds give out energy it is exergonic.

• If the energy is in the form of heat it is Exothermic.

ENERGY CHANGES

• Metabolism consists of anabolism and catabolism.

• Anabolic reactions: Large complex molecules are built from smaller ones. The reactions are endergonic.

• Eg: Protein Synthesis– Photosynthesis

ENERGY CHANGES

• Catabolic reactions: large complex molecules are broken into smaller ones.

• The reactions are exergonic

• Eg. Respiration

• Endergonic reaction: requires energy, usually ATP

• Exergonic reaction: releases energy, occurs spontaneously

Endergonic and Exergonic Reactions

+

+reactants products

energy

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reactants

productsenergy

∆G > 0

∆G < 0

If exergonic reactions occur spontaneously, why isn’t the paper in front

of you on fire?

• An exergonic reaction

Just as the person may need a push to get started down a hill, many of the exergonic reactions that living

organisms depend on for survival may need a “push”.

∆G < 0

Figure 6.12 Energy profile of an exergonic reaction

EA = activation energy

In living organisms the “somethings” that provide that push are called enzymes

Without enzyme:

With enzyme:

Figure 6.13 Enzymes lower the barrier of activation energy

Most enzymes are protein molecules with a specific 3-dimensional shape

enzyme “induced fit”

substrate

Active site

Enzymes catalyze reactions in living organisms: 1. Bring reactant molecules close together

2. Make bonds easier to break/form

Notes about enzymes• Enzymes only increase the rate of

exergonic reactions, they can’t cause non-spontaneous reactions to occur

• Only the substrate will be altered, the enzyme will be released to work again

• Enzymes are one type of catalyst

What determines how well an enzyme works?

• Binding of enzyme and substrate

• Temperature at which the enzyme functions

Can a species’ enzymes be shaped by natural selection?

• Does the same enzyme show variation from one individual to another?

• Is the form of enzyme an individual produce a heritable trait?

• Does the form of enzyme individual produce affect its survival/reproduction?

Figure 6.16 Environmental factors affecting enzyme activity