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Word Splash
• Enzyme Active Site
• Biological Catalyst Activation Energy
• Substrate Denatured
• Lock and Key Reusable
Key Concept
• Enzymes are proteins that speed up chemical rxns in living cells by lowering the amount of activation energy (EA) needed to get them started
Chemical Reactions require E
• Energy is needed to start a chemical reaction.
• This energy is used to
break the bonds within the reactant molecules
• The amount of energy needed is called activation energy (Ea).
Function of Enzymes
• Enzymes make rxns go faster by
reducing the amount of activation energy
needed for the reaction to start
What’s needed to get the rock rolling down the hill on its own? ENERGY INPUT
Activation Energy
A catalyst speeds up the rate of the reaction by reducing the amount of activation energy needed to start the reaction.
Because enzymes have the job of catalysts in living things they’re called biological catalysts.
Enzymes are Biological Catalysts
Enzymes are protein molecules.
How Enzymes Work
Each enzyme has a unique shape with a special area called an active site
Enzyme Shape determines Function
Enzyme – Substrate Complex• One or more molecules called
substrates bond to the enzyme’s active site.
• Together they form an enzyme –substrate complex.
Lock and Key TheoryAn enzyme’s specific shape allows it to fit with only one substrate like a
lock and key.
Enzyme – Substrate Complex• Once the enzyme and substrate
combine a shape change occurs.
The shape change provides the energy needed to caused bonds in the substrate to break or form resulting in new molecules , called products, being formed .
They are then released from the active site.
Enzymes help reactions go faster
An enzyme flick
Let the show begin....
EnzymesEnzymes are reusable – they can be used
over and over again to _______________ a specific reaction.
Each enzyme is unique in its shape and catalytic activity.
Different environmental factors affect how quickly an enzyme can speed up a reaction.
There are certain environmental conditions that cause each type of enzyme to work its best – Optimal condition
Enzymes are Unique
pH
Temperature
Substrate Concentration-amount of substrate molecules
Enzyme Concentration- amount of available enzyme
Factors that Affect Enzyme Activity
The environmental conditions that cause each type of enzyme to work its best are called – optimal level.
For example, 98.6 ° is the optimal temperature for enzymes to work in the human body.
Optimal Conditions
Enzyme Activity Graphs
https://www.youtube.com/watch?v=HnbNcQlzV-4
Affect of Substrate Concentration
Certain conditions can change an enzyme’s shape which makes it unusable.
Denature – change a molecule’s shape
Enzymes can be Denatured
Many diseases are caused by a missing or defective enzyme. Lactose intolerance – missing ______________ __________________________________________ Phenylketonuria (PKU) – missing phenylketonurase. __________________________________________
Enzyme Activity Graph with zones of activity/inactivity
Quick Facts about Enzymes
• Enzymes are protein molecules
• Enzymes function to make reactions
go faster
• Are reusable
• There are about 2000 different enzymes in each one of your cells
• Each enzyme fits with only ________ substrate molecule
• Names usually end in -ase
General Types of Enzymes
• Amylases –
break starch to glucose
• Lipases –
break lipids to fatty acids
• Proteases –
break proteins to
amino acids
• Nucleases – break nucleic acids DNA and RNA to nucleotides
Factors that affect Enzyme Action
How do enzymes work?• Each enzyme has a unique 3-D shape, including a surface
groove called an ACTIVE SITE.
• One or more molecules called SUBSTRATES chemically bond to the enzyme’s active site.
• When joined they are called an ENZYME-SUBSTRATE COMPLEX
• Changes in how the atoms are bonded occur resulting in new molecules being made called PRODUCTS .
• Products are then released from the active site.