Word of the day

• Catalyst: – A substance that increases the speed of a

chemical reaction AND lowers the amount of energy needed

AgendaLatin and Greek QuizEnzyme NotesEnzyme Study Tool

Review

• There are four macromolecules– Carbohydrates– Lipids – Nucleic acids – Proteins

• Monomer: amino acids

• Polymer: polypeptide chains

Let’s study one protein:Enzymes

What do Enzymes do?

• Our body makes many enzymes

• Enzymes are specialized proteins that breakdown or combine molecules into things our cells need

Catalysts

Catalysts: decrease (lowers) the amount of energy needed to start a reaction (activation energy).

Enzyme = catalyst

Each enzyme is specific to a reaction

Ex: Lipase, Protease, Amylase, Lactase, Sucrase, Catalase(Think of a Lock & Key)

Enzyme Animation

• http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html

In our lab toothpickase…

• What represented the enzyme?

• What represented the substrate?

• What represented the product?

Induced Fit Model

• The active site on the enzyme is temporarily reshaped each time the molecules bind

Like a lock and a key – that you have to jiggle

How do Enzymes Work?

1. A substrate(s) fits into a active site on the enzyme.

2. The enzyme lowers the energy required to complete the reaction.

3. The product is released by the enzyme.

Factors that affect rates of enzymes:

1. Temperature—work best at body temp.

Cold = slow, Hot = denatured (change shape)

2. Concentration of enzyme--more enzymes to do the work = faster

3. Concentration of substrate—more to work on = the slower it goes

4. Competition with inhibitors—other substances (ex: drugs) block active site = they work slower

5. pH—each enzyme has a “best” pH. Out of that range they denature.

In our toothpickase lab…..

• What did we do that showed enzyme concentration?

• What did we do to show substrate concentration?

• What did we do to represent the environment?

Denatured Enzyme• Definition: a change in the shape of the enzyme molecule

making the enzyme useless or less effective.

• The substrate no longer “fits” into its’ Active Site.

• Substrate does not fit enzyme does not work

Enzyme Animations

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

Can you……..?

• Define the key words: enzyme, catalysts, substrate, active site, activation energy, products, denatured and substrate specific

• Describe how an enzyme works.

• Describe factors that affect enzymes.

An Enzyme in Action

Can you describewhat is happening here?

ActiveSite

Substrate 1

Substrate 2

P1 P2

Product

P3 P4Which would be the substrate and product for this enzyme?

Substrate 1 and products 3/4

Assignment

• Make a study tool– Must have the word or concept– Must have a picture representing the

word/concept– Must have a written definition of the

word/concept