How do living things get and use energy?
Learning Targets
Learning Experiences
Learning Targets
Learning Experiences
Teacher Tip Direct students to look specifically at Acetylcholinesterase
48 I can compare the activation energy of an
Students explore pre-built or student-designed models to identify the key structural components of enzymes and demonstrate enzymes that are not consumed by the reaction they mediate. Students then analyze a diagram showing how, compared to an uncatalyzed reaction, enzymes lower the energy of activation required for a reaction to proceed. This concept is reinforced through a role play activity simulating enzyme functionality. Through a series of laboratory experiments, students discover how factors that alter protein structure (i.e., temperature, pH, substrate concentration, salinity, etc.) impact the way enzymes function. These concepts are explored within the context of living systems.
47 I can use a model to illustrate the three- dimensional structure of a protein and relate that struc- ture to the biological function of an enzyme. (1)
Students explore pre-built or student-designed models to identify the key structural components of enzymes and demonstrate the relationship between the structure and function of the enzyme’s active site. Students manipulate the models to mimic the processes of competitive regulation and noncompetitive inhibition.
and Insulin models in the Molecules App and make an inference if these proteins have the same or different functions based on their structure. Simply viewing the molecules with the app will not meet the learning targets.
uncatalyzed reaction with an enzyme-mediated reaction using a diagram. (1, 6) 49 I can investigate the factors that affect enzyme function and use that data to draw conclusions about the key components of enzyme functionality in living systems. (1, 6)
Teacher Resources
an additional substrate can produce more color change, because the enzyme is not consumed. • Peroxidase demo: Peroxidase can be collected from liver or potato extract. Show that the addition of H2O2 (hydrogen peroxide) causes bubbling. Once new bubbles cease forming, show students that adding additional substrate causes new bubble formation, indicating the enzyme remains active. • Salivary amylase versus saltine cracker demo: Have students chew on a plain saltine cracker until the cracker begins to taste sweet. Explain the action of salivary amylase is breaking starch into mono and disaccharides. Ask if the same would happen given a new cracker, illustrating that the enzyme is not consumed by the reaction. • Extract peroxidase from turnip root and measure activity under several experimental conditions using a spectrophotometer. bit.ly/measure-enzyme-activity Strategy for Teaching Enzymes NMSI Laying the Foundation Lesson : Pool Noodle models are used to simulate enzyme function. Experimental Design Diagram — Teacher Created Teacher-created diagram that scaffolds students’ planning scientific investigations and can be used with any experimental design. www.hudsonalpha.org/compendium Enzymes — Alabama Science in Motion M2DesEnz Foam models illustrate enzyme-substrate interactions and competitive and noncompetitive inhibition. Available for purchase from 3D Molecular Designs. bit.ly/AMSTI-ASIM
Enzyme Role Play — (groups of four students) Two students will be assigned the role of substrates, third student will serve as the enzyme, and fourth student will serve as the timekeeper. During the first round, the two substrates wander around the room and will not avoid nor seek each other. The timekeeper will stop the timer when the substrates run into each other. Time at which they meet should be recorded by timekeeper. In the second round, the substrates repeat the action from round one, but in the second round, the enzyme will take the arm of one sub- strate and pull it toward the other substrate thereby “bringing them together” at a faster rate. Once the substrates are together, the timer stops and time is recorded. All group members should compare the non-enzyme mediated time with the enzyme mediat- ed time. Debrief activity using enzyme vocabulary. An activity in which students (the enzymes) break toothpicks (substrates), under differing conditions to simulate enzyme action and factors affecting them. bit.ly/toothpickase Enzymes — Alabama Science in Motion L1Enzymes The lab provides three activities to determine the effect of pH, substrate concentration, and temperature on enzyme action. bit.ly/AMSTI-ASIM Toothpick-ase: An Introduction to Enzymes Biology Junction Sample Enzyme Lab Experiments: • Alkaline phosphatase and PNPP (these reagents are commonly used in the AP Biology Enzyme Inhibition lab): Demo purpose is to show that adding
Teacher Resources
Molecules — Sunset Lake Software This free iTunes ® phone or tablet app provides digital models of common enzymes that can be manipulated to observe enzyme structure. bit.ly/sunset-lake-molecules Amino Acid Starter Kit — 3D Molecular Designs Uses flexible toobers and amino acid clips to model protein folding. This kit was distributed during GREAT ® workshops 2012/14 and is available as part of the Designer Enzymes Kit from ASIM – M2DesEnz. bit.ly/AMSTI-ASIM
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39
A Field Guide to the Alabama Standards
38
The Biology Compendium
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