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Color after Biuret Test
Catalyst #4: October 27th, 2014 Which macromolecule is the Iodine test used to detect? You perform Benedict’s test on a solution and the solution turns orange. Which macromolecule was present in the solution? 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
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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
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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!
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Objectives: SWBAT identify the major components of a chemical reaction. SWBAT identify and analyze the effects of enzymes on biological reactions.
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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?
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Chemical Reactions Many processes occurring in living organisms involve chemical reactions Digestion, cell division, muscle contractions, etc.
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Chemical Reactions: Key Point 1
A 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?
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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
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CFU 1 Which of the following is the best definition of a catalyst?
A substance that decreases the rate of a reaction but is not used up during the reaction A substance that decreases the rate of a reaction and is used up during the reaction? A substance that increases the rate of a reaction but is not used up during the reaction A substance that increases the rate of a reaction and is used up during the reaction
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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
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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
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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
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Why is it important? 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!
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CFU 2 Which of the four macromolecules are enzymes? Answer: Proteins
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CFU 3 What effect do enzymes have on the rate of a chemical reaction?
Answer: Increase the rate
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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
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Energy of Reactions: Key Point 5
All chemical reactions require energy
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Activation Energy: Key Point 5 cont.
The minimum amount of energy needed for a reaction to occur is known as the activation energy
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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?
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Enzymes & Activation Energy: Key Point 5 continued
Enzymes increase the rate of reactions by decreasing the activation energy of the reaction
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CFU 4 Which curve (upper or lower) shows the energy change for a reaction with an enzyme present? Answer: Lower (black)
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CFU 5 What is the definition of activation energy?
Answer: The minimum amount of energy needed for a reaction to occur
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Other Uses of Enzymes Other uses of enzymes include: Bread production
Wine production
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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
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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
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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 equation 6 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. Enzyme Think Tac Toe
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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?
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October 28th, 2014 We will be completing the Macromolecule Tests Mini-Assessment. 3 questions! You need a sheet of paper labeled “Macromolecule Tests Quiz”
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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)
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Announcements Dojo Honors rubrics Office hours tomorrow Edmodo poll
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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
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Announcements Dojo Office hours today
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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.
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Enzyme-Substrate Complex
Products Active Site Enzyme Enzyme-Substrate Complex
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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.
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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?
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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
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Catalyst #5: October 29th, 2014 What effect do enzymes have on the rate of chemical reactions? How many different substrates can an enzyme bind? What is activation energy? How do enzymes speed up chemical reactions?
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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
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Announcements Mastery Packets due NOVEMBER 3rd (MONDAY!) Edmodo poll
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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
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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
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Factors Affecting Enzyme Activity
Most enzymes work best at an organism’s natural temperature (98.6°F for humans) and pH (7)
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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
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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
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Enzyme Trashketball Enzyme worksheet: TURNING IN FOR A GRADE
Everyone will answer the next question. A RANDOM person from your team will be called on to answer. Anyone can take a shot!
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