Objective: Identify How Enzymes Are Specific to Substrates

Lesson 17. Enzyme Specificity

Objective: Identify how enzymes are specific to substrates

EQ: Why do we have so many different enzymes in our bodies?

Bridge: Give the students a handful of puzzle pieces (I bought a few puzzles from the dollar store) and ask them to put together their pieces. I mixed and matched the puzzles so that there were 2 sets of 2 pieces that fit together and a couple that did not. In many cases it is best to buy the puzzles with the larger pieces: a lot of our students have dexterity issues that you wouldn’t even guess 

Mini Lesson: Ask the students to share out what happened in their bridge. Guiding Questions: Why could they only fit together a couple of the pieces, but not other ones? What was the purpose of putting together a puzzle in the first place?

Have them take a look at part one of their activity today. Have them complete it and ask them to relate it back to the bridge. How was this the same?

Cutting and Arranging Pieces Directions: For the yellow pieces, you will need to have one piece labeled as enzyme and then 3 pieces labeled as substrate A B and C. Cutting a group of them out will give you 2 sets at least to work with.

Discuss with them that enzymes are a lot like the puzzle pieces in both of these activities: they will work when they need to do a specific job and the “pieces” are there for them to do their job. The activity that they are participating in will focus on this.

The most common jobs of enzymes are to digest large molecules (to take something big and make it into two smaller, new pieces) or to synthesize new molecules from old ones. Give expectations for work period.

Work Period: second part of the activity

**This one takes time to cut out all of the pieces for this lab. Allow yourself an hour to cut and expect sore fingers when you are done. You can cut back on time by doing a few things…

1. Make the little pieces on the back page bigger. I scanned them in so you can resize the whole image.
2. Have the kids work in groups instead of doing it themselves then you have less to cut out then just have them draw on the paper what they came up with.

Cutting and Arranging instructions:

For the colored pieces, the first set of three is the digestion reaction (the large purple breaks into the smaller red and purple pieces. The other set is synthesis where 2 pieces become something new. Cut on the lines for each group and they get all 6 pieces cut up. This is

Summary: Answer the EQ using today’s activity and the knowledge from the last few lessons.

Closing: Based on what you did today, what does a change in temperature and pH from the optimal range do to an enzyme to make it not work?

Independent Practice: Regents Questions

SPED and ELL Modifications:

Have students work together to complete all activities in this lab as it is direction intensive

Apps and Internet Activities:

You could set up this activity as a station and allow students to watch the video and post comments about enzymes and shape importance.

This article could be used as a homework or a separate station for accelerated students who tend to complete their work quickly (read and write a summary of the article)