campfire answer questions from handout put on page 36 warm up
TRANSCRIPT
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)
Class Norms
Common Board ConfigurationDATE: 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.
AgendaInteractive 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.
H2O2 -----------> H20 + O2
• A reaction is at equilibrium when reactants and products form at the same rate.
CO2 + H2O H2CO3
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
45Squar
e
“L”
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 anenzyme 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 anenzyme at certain places called active sites.
The enzyme bringssubstrates together and weakens their bonds.
The catalyzed reaction formsa product that is releasedfrom the enzyme.