Enzyme Reactions

Enzyme Characteristics

• Most often are proteins

• Biological catalysts – speeds up chemical reactions

• Reusable – Used in multiple reactions• Summer t-shirt

• Specific – One type of enzyme for one type of reaction

Enzyme substrate reactionsSubstrate: Substance that the enzyme is working on

Active Site: Location where enzyme attaches to the substrate

Enzyme Example: Salivase

• Found in saliva

• Begins the digestive process of carbohydrates in the mouth

• Makes it easier for carbohydrates to be digested– Process would NOT start and

probably would not finish if salivase was absent = Too much energy would be needed!!!

How Enzymes Work

Reaction

Energy

Plot of the Story: You need a lot of energy to begin a chemical reaction

Activation Energy

How Enzymes Work

Reaction

Energy

Enzymes reduce the amount of activation energy needed to start a reaction

How Enzymes Work

Reaction

Energy

Less energy is used to conduct the reaction so more reactions may occur thanks to an enzyme

Our Hero!

Another Enzyme Example

• The Dilemma: How do we move these cinder blocks from my room to Mr. Hobb’s room?

• Possible Solutions???

Enzyme Example: Take 2

Typical Ways Enzymes WorkEnzymes may

hold two molecules together in a specific way so that they can react

Example: Dehydration synthesis

Typical Ways Enzymes Work

Enzymes may twist molecules

into more reactive forms

Typical Ways Enzymes Work

Enzymes can break apart macromolecules into monomers

Ex. Hydrolysis

Factors that limit enzyme-substrate reactions

• Amount of Substrate– When all substrate is used up, the reaction stops

• Temperature– Most enzymes in our body function best at 37C– Hotter temperatures may destroy the enzymes

Another Enzyme Example: The Pancreas

• Function: Secrete enzymes to break down macromolecules during digestion

• Importance: Without these enzymes we would not be able to break down food sufficiently to monomeric units

Pancreatic Enzymes: 4 Types

• Proteasis – Proteins

• Lipases – Lipids

• Carbohydrases – Carbohydrates

• Nucleasis – Nucleic Acids

Jell-O• Jell-O contains a

protein called GELATIN which causes Jell-O to gel

Without Gelatin, Jell-O would fail to gel and you would have liquid Jell-O

Jell-O Continued

• Certain Fruits contain enzymes known as proteases that destroy gelatin

ProteaseLiquid Jell-O

Jell-O Continued

• Certain dish and laundry soaps have incorporated these fruit derived enzymes in efforts to remove stains from dishes and clothing

Jell-O

• In today’s lab we are going to investigate which fruits contain these enzymes

• You will be working by yourself on this one• You will need to include the following sections in

your report– Introduction– Methods– Results: A table indicating whether or not a fruit

contains enzymes– Conclusion

The Fruits of Interest

• Apple

• Banana

• Pineapple

• Kiwi

• Orange

• Lime