Wayne County Regional Enhancement Education Millage Proposal

 

School districts in Wayne County have placed a proposal on the November 8th ballot to provide added funding for our schools. It is the “Regional Enhancement Millage Proposal.”

If approved by the entire county, the 2 mil proposal will generate approximately $6.2 million from Dearborn but the District will receive $7.8 million in additional funding for our schools.  Money would go to local schools starting this year and the millage expires after six years.  Read more

Wayne County Regional Enhancement Education Millage Proposal

 

School districts in Wayne County have placed a proposal on the November 8th ballot to provide added funding for our schools. It is the “Regional Enhancement Millage Proposal.”

If approved by the entire county, the 2 mil proposal will generate approximately $6.2 million from Dearborn but the District will receive $7.8 million in additional funding for our schools.  Money would go to local schools starting this year and the millage expires after six years.  Read more

Notice for AOL Email Accounts

Dear Parents,

If you are an AOL email user, please be aware that you may not receive email notifications due to AOL policies. We are working to resolve this issue with AOL.

Thank you for your patience while we work with AOL to make sure you get classroom notifications from your teacher.

Sincerely,

Technology Department

Enzymes

Life is built on chemical reactions.  All of the processes of life involve building molecules (synthesis) or breaking them down (digestion).  Whether building up molecules or breaking them down, all cells need enzymes to help out with these chemical reactions.

PepsinEnzymes are reusable proteins–or sometimes RNA molecules–that help to speed up chemical reactions.  Because of this, enzymes are considered catalysts.  Each enzyme is the specific helper for a specific reaction.  Enzymes are named for the reaction they help.  For instance, the enzyme sucrase helps to break down sucrose.  Protease enzymes help break down proteins. As you can see, an enzyme’s name usually starts with a word that is similar to the molecule it breaks down or builds up, and ends with the suffix -ase.

In order to do its job, an enzyme needs to be the right shape.  Since enzymes are usually proteins, there are several factors that can affect the ability of an enzyme to do its job.  One way that an enzyme’s effectiveness could be limited is if its amino acid chain is out of order.  Since different amino acids have different chemical properties, having just one or two of the wrong amino acids in the wrong place could completely change the structure of the enzyme molecule.  When an enzyme’s structure is changed, it can no longer perform its function.

There are other factors that affect enzyme activity.  Each of these also affects the enzyme’s shape.  Take temperature, for instance.  All enzymes have a temperature at which they operate best, called the optimum temperature.  temperature and enzymes2For humans, the optimum temperature is around 37 degrees C (or 98.6 degrees F).  Go too high above the optimum temperature, and the protein could unfold or lose shape.  If the temperature gets too low below the optimum temperature, molecules slow down and the enzymes have a lower chance of actually running into the molecule that they are meant to work on.

Finally, pH affects the activity of an enzyme.  The pH of a solution is a measure of how acidic or basic the solution is.  Based on a range of 0 to 14, the lower the pH, the more acidic the solution is.  On the other hand, the higher the number, the more basic the solution is.  Most solutions inside cells are around a pH of 7, which is considered neutral.  For this reason, most enzymes operate best at a pH of 7.  However, there are certain enzymes within the human body that operate best at other pH levels, such as the enzyme pepsin in your stomach.  Pepsin operates best at a very low pH–around 2 or 3–which explains why your stomach contains acid.  Your stomach is only acidic because it is providing the conditions for pepsin to do its work.  As was the case with temperature, the wrong pH level for the wrong enzyme could mean its shape will change and it will no longer be able to do its job.

Preparing for Friday’s Test: Study Guides!

To help you prepare to demonstrate your understanding of cell division (chapter 8 in Modern Biology), I have made several study tools available to you.  The following resources have been and will continue to be available to you:

  1. the Mitosis Pretest and sections 8-1 and 8-2 quizzes on iLearn
  2. vocabulary list with definitions, available by clicking the “Vocabulary” tab at the top of this site
  3. virtual flashcards on StudyBlue.com
  4. NEW! Shared folder containing notes and resources from this unit, available by clicking the “Notes” tab at the top.  You will need to log in with your dearbornschools.org ID.
  5. the vocabulary study guide distributed in class
  6. the online practice quizzes and study guides available with the online textbook.  Click here for instructions on how to get to the online textbook.
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