1. which macromolecule is the iodine test used to detect? 2. you perform benedict’s test on a...
TRANSCRIPT
Catalyst #4: October 27th, 2014
1. Which macromolecule is the Iodine test used to detect?
2. You perform Benedict’s test on a solution and the solution turns orange. Which macromolecule was present in the solution?
3. The Biuret test is done on four different foods. Based on the chart below, what foods contain protein?
Food Color after Biuret Test
Egg yolk Purple
Orange Juice
Light blue
Potatoes Blue
Milk Light purple
Agenda
Catalyst (5 minutes)Chemical Reactions, Part 1 (5 minutes)Elephant Toothpaste (10 minutes) Enzymes, Part 2 (10 minutes) Enzyme ThinkTacToe Homework:
DBA #9: 11/3 Honors Projects, due Dec. 3rd
Announcements
Evolution Grade slips/Tracking Included: Mastery grades for Adaptations,
Natural Selection, Evidence for Evolution, and Classification
Additional: DBA #5 and #6, Honors FRQ from Unit 2 assessment
Dojo review tomorrow Honors rubrics Edmodo poll!
Objectives:
SWBAT identify the major components of a chemical reaction.
SWBAT identify and analyze the effects of enzymes on biological reactions.
Unit 3: Guiding Questions What molecules are found in all
living organisms?
Why do we need to eat a balanced diet that contains a variety of foods?
What is responsible for making sure that the reactions occurring in living organisms occur quickly enough?
Chemical Reactions
Many processes occurring in living organisms involve chemical reactions Digestion, cell division, muscle
contractions, etc.
Chemical Reactions: Key Point 1A chemical reaction is the
process by which one or more substances are reorganized into different substances Reactants Products▪ Reactants are the starting substances▪ Products are the substances formed▪ Examples?
Catalysts: Key Point 2
Catalysts are substances that increase the rate of chemical reactions without being used up in the reaction. To increase the rate of a chemical
reaction means to speed up a reaction
CFU 1
Which of the following is the best definition of a catalyst?A. A substance that decreases the rate of a
reaction but is not used up during the reaction
B. A substance that decreases the rate of a reaction and is used up during the reaction?
C. A substance that increases the rate of a reaction but is not used up during the reaction
D. A substance that increases the rate of a reaction and is used up during the reaction
Elephant Toothpaste Demo Reactants:
Potassium iodide Catalyst: Hydrogen
peroxide Products: Water
and oxygen
Exothermic reaction = creates a lot of heat
Real world: Hydrogen peroxide to
treat cuts the catalyst catalase in blood cells causes the bubbling
Have you ever….?
Gotten sick? Had a sugar rush? Gotten a muscle cramp? Had a scar form from an injury?
Felt too hot or too cold?
*Additional notes
Enzymes: Key Point 3
Enzymes are proteins that are catalysts for many biological processes
Enzymes increase the rate of chemical reactions They speed up the reactions, but they
are not used up during the reaction
WITHOUT ENZYMES, OUR INTESTINES WOULD TAKE WEEKS TO DIGEST OUR FOOD, OUR MUSCLES, NERVES AND BONES WOULD NOT WORK PROPERLY, AND SOON DEATH WOULD RESULT!
Why is it important?
Enzyme Characteristics: Key Point 4
Enzymes are specific: Only one type of substrate works! Lock and key
Enzymes are reuseable: Can be used over and over again and is not changed by a reaction
Enzymes can denature: Change shape because of changes in temperature or pH (Remember, proteins are 3D!)
Additional notes: Many end in the suffix –ASE-Sucrase-Lipase-Catalase
Activation Energy: Key Point 5 cont.
The minimum amount of energy needed for a reaction to occur is known as the activation energy
Activation Energy: Athletes
Say Ms. M is tired of feeling old and decides to race a student from one side of the room to the other. To prove that she’s faster, Ms. M even allows the student to start behind the starting line while Ms. M starts right on the line. Who will win? Why?
Enzymes & Activation Energy: Key Point 5 continued
Enzymes increase the rate of reactions by decreasing the activation energy of the reaction
CFU 4
Which curve (upper or lower) shows the energy change for a reaction with an enzyme present?
Answer: Lower (black)
CFU 5
What is the definition of activation energy?
Answer: The minimum amount of energy needed for a reaction to occur
CFU 6
The enzyme lactase is involved in the reaction that breaks down the sugar lactose. What effect does the enzyme lactase have on this reaction?
Answer: Lactase speeds up the reaction
Summary
Catalysts are substances that increase the rate of (speed up) chemical reactions without being used up
All chemical reactions require energy Activation energy is the minimum amount of
energy needed for a reaction to begin Enzymes are proteins and catalysts for
reactions Every enzyme can only bind one specific
substrate Enzymes speed up reactions by lowering
activation energy On a graph, reactions with enzymes have
lower activation energies and shorter reaction times
Enzyme Think Tac Toe T H I N K
Provide three examples of chemical reactions that occur in the human body.
What macromolecule are enzymes?
How do enzymes affect the rate of a chemical reaction?
What curve (top or bottom) represents a reaction without enzyme activity?
Hypothesize what would have occurred in the Elephant Toothpaste demo if hydrogen peroxide had not been added.
Identify the reactants and products in the chemical equation6 O2 + C6H12O6 6 CO2 + 6 H2O
Define activation energy.
Why is an enzyme considered a catalyst?
The enzyme amylase is involved in digesting carbohydrates in the stomach. What effect does amylase have on the speed at which your body digests carbohydrates?
Your friend was absent today. When he or she comes back, they are really confused about activation energy. How would you explain activation energy in your own words? Use an analogy (comparison) like Ms. Mitchell did with the sprints.
Exit Ticket: Slap the Door
1. What is an enzyme? 2. What are the 2 parts of a chemical
reaction? 3. What does a catalyst do to a
chemical reaction?
October 28th, 2014
We will be completing the Macromolecule Tests Mini-Assessment.
3 questions! You need a sheet of paper labeled “Macromolecule Tests Quiz”
Agenda
Catalyst: 8 minutes Enzyme Structure: 10 minutes 3D enzyme “art project”: 25 minutes Exit ticket: 2 minutes
Reminders: DBA #9:11/3 Honors Projects 12/4 Study for Enzyme Quiz (Thursday)
Agenda
Catalyst (5 minutes) Enzyme Review Questions (10
minutes) Elephant Toothpaste Demo (10
minutes) Enzyme Art Project (Remaining)
Homework: Classwork you do not finish
Study for enzyme quiz
Objectives
SWBAT define the three components of an enzyme based reaction.
SWBAT explain the lock and key model
SWBAT create a 3D model of an enzyme.
Enzyme Art Project
1. Create your own unique enzyme shape. (Think puzzle piece). Make sure your enzyme has a “groove.” Label it active site.
2. Cut out your enzyme and the piece from the groove. Label that “substrate.”
3. Create several other substrates that will not work with your enzyme.
Your enzyme and substrate must be labeled. They should be colored and glued to another sheet of paper. THEN ANSWER THE QUESTIONS ON THE BOARD.
Enzyme Art Project Questions/Exit Ticket
1. What are the three characteristics of enzymes?
2. What does the “lock and key” model mean?
3. Would your enzyme work with other substrates made in the class?
Enzyme Questions + Trashketball
Answer each of the enzyme questions independently.
Trashketball expectations/rules: When it is your team’s turn, I will
randomly call on a member of your team.
Get it right = anyone can take a shot Get it wrong = the other team can
steal
Catalyst #5: October 29th, 2014
1. What effect do enzymes have on the rate of chemical reactions?
2. How many different substrates can an enzyme bind?
3. What is activation energy?4. How do enzymes speed up chemical
reactions?
Agenda
Catalyst: 5 minutes Factors Affecting Enzyme
Performance: 10 minutes Enzyme Trashketball: Remaining
Reminders: DBA #9: 11/3 Honors Projects 12/4 Enzyme Quiz TOMORROW
Review Catalysts are substances that increase the rate
of (speed up) chemical reactions without being used up
Enzymes are proteins that increase the rate of chemical reactions (catalysts)
Every enzyme can only bind one specific substrate
Activation energy is the minimum amount of energy needed for a reaction to begin
Enzymes speed up reactions by lowering activation energy
On a graph, reactions with enzymes have lower activation energies and shorter reaction times
Factors Affecting Enzyme Activity
Enzymes work best under certain conditions
Different factors can affect the activity of enzymes (how well they work) Temperature, pH, substrate
concentration
Factors Affecting Enzyme Activity
Most enzymes work best at an organism’s natural temperature (98.6°F for humans) and pH (7)
Factors Affecting Enzyme Activity
When the temperature or pH is higher or lower than normal, enzymes do not function as well Higher or lower temperature than normal=
slower reaction Higher or lower pH than normal= slower
reaction
Factors Affecting Enzyme Activity
Recall, substrates are the molecules that bind to enzymes during a chemical reaction
The concentration (relative amount) of substrate affects the activity of enzymes Higher substrate concentration= faster
reaction Lower substrate concentration= slower
reaction