Skip to main content

You are here

Filters

Search found 3 items

Biochemistry And Molecular Biology

  • A three-dimensional model of methionine is superimposed on a phase contrast micrograph of Saccharomyces cerevisiae from a log phase culture.

    Follow the Sulfur: Using Yeast Mutants to Study a Metabolic Pathway

    Learning Objectives
    At the end of this lesson, students will be able to:
    • use spot plating techniques to compare the growth of yeast strains on solid culture media.
    • predict the ability of specific met deletion strains to grow on media containing various sulfur sources.
    • predict how mutations in specific genes will affect the concentrations of metabolites in the pathways involved in methionine biosynthesis.
  • Enzymatic avocado browning is driven by polyphenol oxidase. Mashed avocado pulp is bright green but turns dark brown over the course of two hours at room temperature in the presence of air and salt. This reaction can be accelerated or inhibited by more than 20 different testable reagents, allowing students to explore experimental design.

    The Avocado Lab: An Inquiry-Driven Exploration of an Enzymatic Browning Reaction

    Learning Objectives
    Students will be able to:
    • develop a testable research question and supportive hypothesis regarding the browning of damaged avocado flesh caused by the activity of avocado polyphenol oxidase (aPPO).
    • design and execute a well-controlled experiment to test aPPO hypotheses.
    • evaluate qualitative enzyme activity data.
    • create a figure and legend to present qualitative data that tests multiple hypotheses and variables.
    • search for and correctly cite primary literature to support or refute hypotheses.
    • know the role of reducing reagents, pH, chelators, and temperature in reactions catalyzed by aPPO.
    • explain why the effects of salt and detergent differ for aPPO experiments conducted in situ
    • (in mashed avocado flesh) as compared to in vitro (on purified protein).
    • discuss how substrate and cofactor availability affect aPPO reactions.
    • describe how endogenous subcellular organization restricts aPPO reactions in a healthy avocado.
    • evaluate food handling practices for fruits expressing PPO.
  • Sodium-Potassium pump

    Lights, Camera, Acting Transport! Using role-play to teach membrane transport

    Learning Objectives
    At the end of this activity, students should be able to:
    • Compare and contrast the mechanisms of simple diffusion, facilitated diffusion, and active transport (both primary and secondary).
    • Identify, and provide a rationale for, the mechanism(s) by which various substances cross the plasma membrane.
    • Describe the steps involved in the transport of ions by the Na+/K+ pump, and explain the importance of electrogenic pumps to the generation and maintenance of membrane potentials.
    • Explain the function of electrochemical gradients as potential energy sources specifically used in secondary active transport.
    • Relate each molecule or ion transported by the Na+/glucose cotransporter (SGLT1) to its own concentration or electrochemical gradient, and describe which molecules travel with and against these gradients.