Presentation on theme: "CAMPFIRE Answer questions from handout put on page 36 Warm up."— Presentation transcript:
CAMPFIRE Answer questions from handout put on page 36 Warm up
Honor time limits Actively participate (Have S.W.A.G.) Listen respectfully to your colleagues Place cell phones on vibrate or silent mode Participants may write burning questions on a sticky note and place on the parking lot BE PRESENT (Develop H.O.T.S. for Science)
DATE: September 15, 2014 ESSENTIAL QUESTION: Why are the actions of enzymes important to us? Home Learning: Textbook (page 62) Answer Questions 30-35 (on left side) Objectives: Explain the role of enzymes as catalysts that lower the activation energy of biochemical reactions. Identify factors, such as pH and temperature, and their effect on enzyme activity.
Interactive Journal Role of Enzymes Complete Roles of Enzymes graphs on page 36 in ISN Exit Ticket
Bonds break and form during chemical reactions. Chemical reactions change substances into different ones by breaking and forming chemical bonds. Reactants are changed during a chemical reaction. –Products are made by a chemical reaction. H 2 O 2 -----------> H 2 0 + O 2
A reaction is at equilibrium when reactants and products form at the same rate. CO 2 + H 2 O H 2 CO 3 Bond energy is the amount of energy that breaks a bond. –Energy is added to break bonds. –Energy is released when bonds form.
Variables Independent Variable Condition or factor that is manipulated by a scientist during an experiment Dependent Variable Factor that changes throughout the experiment Constant Condition that is controlled so that it does not change during an experiment
Warm Up Which of the shapes on the right will combine with the “L” on the left, to complete the square (objects can only be rotated, not flipped) 1 2 3 4 5 Square “L”
CO 2 + H 2 O H 2 CO 3 Review Which are reactants? Which are products? This reaction is at ______________.
Chemical reactions release or absorb energy. Activation energy is the amount of energy that needs to be absorbed to start a chemical reaction.
Exothermic reactions release more energy than they absorb. –Reactants have higher bond energies than products. –Excess energy is released by the reaction. –Example: Burning of paper – gives off heat
Endothermic reactions absorb more energy than they release. –Reactants have lower bond energies than products. –Energy is absorbed by the reaction to make up the difference. –Example: plants absorbing sunlight to make food
A catalyst lowers activation energy. Catalysts are substances that speed up chemical reactions. decrease activation energy increase reaction rate Q: What was our catalyst during the lab?
Enzymes allow chemical reactions to occur under tightly controlled conditions. Enzymes are catalysts in living things. Enzymes are needed for almost all processes. –Most enzymes are proteins. –Q: What conditions did we change in our lab? –Q: What were the ideal conditions?
Disruptions can prevent enzymes from functioning. –Enzymes function best in a small range of conditions. –Changes in temperature and pH can break hydrogen bonds. –An enzyme’s function depends on its structure.
An enzyme’s structure allows only certain reactants to bind to the enzyme. substrates (reactants) enzyme Substrates bind to an enzyme at certain places called active sites.
The lock-and-key model helps illustrate how enzymes function. –substrates brought together –bonds in substrates weakened Substrates bind to an enzyme at certain places called active sites. The enzyme brings substrates together and weakens their bonds. The catalyzed reaction forms a product that is released from the enzyme.
Answer the following questions in Interactive Notebook Textbook (page 62) Answer Questions 30-35 (on left side)