Enzymes

Which reaction is more efficient?

C12 H22 O11 +maltase C6 H12 O6 + C6 H12 O6 +maltase 20 sec

C12 H22 O11 C6 H12 O6 + C6 H12 O6 20 min

What makes the 1st reaction different from the 2nd?

Catalyst (General Name)

• Inorganic or organic substances that speed up the rate of chemical reactions without entering the reaction itself

• Catalyst are needed so that chemical reactions take place in a timely manner in an organism

Enzymes (Biological Name)

• Enzymes are biological catalysts!• Organic catalysts that allow chemical reaction in

living organisms to take place quicker than without an enzyme.

• Biological enzymes are protein compounds• Enzymes are used to speed up reactions in the

synthesis or the hydrolysis of biochemical reactions

Enzyme Vocabulary

• Active Site: the area where the enzymatic reaction takes place

• Substrate: The substance that the enzyme works on

• Products: the substances formed after an enzymatic reaction

• Activation Energy: the initial energy needed for the reaction to begin

Hydrolysis with an Enzyme

Characteristics of Enzymes

• Most enzyme names end in –ase (catalase, maltase, lipase, DNAase, protease)

• Enzymes lower the activation energy needed to start a chemical reaction

• Enzymes can be destroyed (DENATURED) if they are not kept in the proper conditions ~ 45o Celcius

• Enzymes begin to lose their conformation (amino acid folding) at high tempresults in losing their function

So What?

• Enzymes are needed so that organisms can carry out biochemical reactions efficiently and in a timely manner

• Enzymes allow us to break and make molecules when we are in need of them

• Enzymes LOWER the ACTIVATION ENERGY IN A CHEMICAL REACTION that’s why the reaction goes faster.

Lock and Key Theory

• Just like how every lock has a particular type of key that will open it, each enzyme has a particular substrate that it can act upon based on – Size, shape, and specificity of the substrate

Induced Fit Model

• The active site on the enzyme changes (wraps around) to fit the shape of the substrate

• Results in enzymatic activity and product formation

• This means that an enzyme can work on more that one substrate if this model is used.

• This model is not as rigid as the lock and key theory. It suggests that the enzyme is more relaxed and can be changed if needed.

Induced Fit Model

Enzymes at work!

Enzymes are not part of the reaction

• Enzymes can be re-used in chemical reactions

Let’s Review Enzymes

• http://www.lpscience.fatcow.com/jwanamaker/animations/Enzyme%20activity.html

Questions to ponder?

• Most enzymes in your body work at what temp?• If that temperature changes how would this

affect enzyme activity in your body?• Can people die from improper enzyme activity? • What would be the biological effects of this?

The pondering answers

• Body temp is about 98.6-98.7• Enzyme activity would slow down due to the

enzymes becoming denatured• Absolutely…ever seen people freeze or

dehydrate to death…enzyme activity stops…remember Titanic

• Enzyme activity slows down and biochemical reactions can cease

3-2-1 Summary

• 3 parts to an enzymatic reaction is…

• 2 ways to recognize an enzyme is…

• 1 way to destroy an enzyme is…

Facts about enzymes

• As we age, the levels of our body enzymes generally decrease.

• If you are lactose intolerant, you are lacking the enzyme lactase in your body

• Amylase is an enzyme found in our saliva and in the enzyme blend released from the pancrease.