[Bio3] Activities for 18-19 Nov 2013

  1. Day 1 for all sections – Library pair work on The Search for the Genetic Material available here or via your photocopy person. Please submit to your class president when done. Class presidents will collate and place the submissions in my cubbyhole at the Bio Unit.“Visit http://www.dnai.org/timeline/ and explore the various important scientists’ contributions and fill in the blanks with their contributions to the discovery of DNA as the genetic material.”
  2. Day 2 for Charm and Gluon – Please proceed to ASTB 203 for your enzyme quiz. Pass your enzyme worksheets (if you haven’t yet) to Sir Leo before the quiz.
  3. Day 2 for all sections – Deadline of the Enzyme Lab Rep (thanks to those who have submitted!)

[Bio3] Computer-aided activity on enzymes

Hello ChElGluGrav! Welcome to the third quarter! 😀

  1. Please work on the pair SW mindfully.
  2. Make sure you understand each answer you write on your worksheet.
  3. Submit your worksheets at the end of the period for grading.
  4. Announcements for next week:
    • Submit your Biomolecules pre-lab, data table, and answers to questions (with APA citations and list of references) during the second meeting next week.
    • We will have a laboratory activity on enzymes during the first two meetings of next week (Nov11-13) and we will meet at SHB109.
    • Groupings will be the same as in the biomolecules activity.
    • Please download the procedure for the lab activity here. Instead of a pre-lab, please do Part II, Steps 1-4 before coming to class on the first meeting next week.
    • A short quiz on enzymes will be given on the second meeting next week before the second part of the lab activity. 


Overview: Enzymes and activation energy

View Part I of the animation at http://www.sumanasinc.com/webcontent/animations/content/enzymes/enzymes.html , click on “show narrative” and answer the questions that follow.

  • What is the activation energy (EA) of a reaction?
  • How do enzymes affect the EA of a reaction?

Enzyme structure and function
View http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html, click on “text” and answer the next question:

  • On a molecular level, how does the shape of an enzyme enable it to perform its function? Use all the following terms in your answer: active site, substrate, enzyme-substrate complex, and product.

View http://www.wiley.com/college/boyer/0470003790/animations/enzyme_binding/enzyme_binding.htm, click on “Binding Models” and answer the next question:

  • What is the difference between Emil Fisher’s lock-and-key model and Daniel Koshland’s induced fit model? What is the current model like?

Factors that affect enzyme action

  • Knowing what you know about the nature of enzymes, predict how the following factors affect enzyme function:

Factors Effect on reaction rate if factor is reduced/decreased Effect on reaction rate if factor is raised/increased Brief explanation as to why these factors affect enzyme function and reaction rates in that way

    • a. Enzyme concentration
    • b. Substrate concentration
    • c. Inhibitor concentration
    • d. Temperature
    • e. Size of container
    • f. pH
  • View http://moleculesoflife2010.wikispaces.com/file/view/Enzyme+Model.swf and test your hypotheses using controlled experiments (you may need to use a timer to assess reaction rates). Do your results agree with your predictions? Write a short summary of your results below.

View http://programs.northlandcollege.edu/biology/Biology1111/animations/enzyme.html and click on “Enzyme Inhibitors” and answer the question below.

  • What is the difference between a competitive and noncompetitive inhibitor?

View http://programs.northlandcollege.edu/biology/Biology1111/animations/enzyme.html and click on “Allosteric Enzymes” and answer the question below.

  • What are allosteric enzymes?
  • We learned in Bio2 that the haemoglobin molecule exhibits cooperativity. What happens to the structure of haemoglobin once oxygen binds to a subunit?

View http://programs.northlandcollege.edu/biology/Biology1111/animations/enzyme.html and click on “Feedback Inhibition” and answer the question below.

  • Feedback inhibition regulates metabolic pathways that use more than one enzyme. How does feedback inhibition work?