Cellular Respiration - Discovery

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Objective

Students will be able to discover basic ideas about cellular respiration.

Big Idea

Where does (almost) all energy come from?

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Purpose of Lesson:

The purpose of this lesson is to introduce the concept of energy to the class, gather information about prior knowledge and discover where the energy originally comes from.

  

Major Strategies to Watch for:

1. Thinking maps- Circle map and flow map used to organize and house information.

2. Last one standing-Elicit many ideas and share with the class in a slightly competitive format.

Ready. Set. Engage!

5 minutes

Learning Goal: Discovery where the energy that we use comes from.

Opening Question:  Where do you think the energy that we use in our lives comes from?

Students record their opening question on their learning goal sheet and are ready to start class 3 min after the bell has rung.  I reward students who get started early with ROCK STAR SCIENTIST tickets.  

Follow the links to learn more about the beginning of class strategies and ROCK STAR scientist tickets.   

Hook

5 minutes

Once the students are ready for class to begin, I draw their attention to the learning goal and let the students think-pair-share about where energy comes from.  Then I preview the Where Does Energy Come From video by explaining that our goal is to figure out where energy comes from.  I encourage the students to look for their ideas in the video and see whether they were right!  That gives them a purpose for viewing.

I also let them know that the video is done from the perspective of a caveman. Finally, although the this video is a great introduction, it ends abruptly. This is fine for our purposes because we are simply introducing the topic.

Pre-Assessment

5 minutes

Pre-assessment is important in teaching because it lets you know the level to teach to. However, it doesn't have to be a pencil and paper quiz or worksheet. I find that I am constantly pre-assessing at the beginning of lessons and altering my lesson plan slightly. This might look like spending more time in one area than another or in skipping activities entirely. 

Today's pre-assessment is the question, "What is energy?"

I set this up by going back to the learning goal and restating that we are trying to figure out where energy comes from but that before we do this we need to know what energy is.  

I find that generally the class falls out into three groups.

  1. The students that have a strong idea of what energy is.
  2. The students that can give examples of energy but not explain it.
  3. The students that really have no clue about energy yet.

Here are two examples of student work.

 

Depending on the size of the categories, you can shape the class to meet the learning level of MOST of the students. For some students today's work might be review. That's okay, because review makes ideas stronger and these students will have a chance to extend their thinking later. For some students today's work may be brand new.  That's okay too because these students will be working on these concepts for the whole unit. In my class, the majority of the students are in category 2.  

To answer the pre-assessment question, I have students draw a circle map in their lab notebooks. They put the word energy in the middle. Then I gave the students 30 seconds to write some ideas down. Once they write their ideas down they get to visit three other people in the room to get more ideas.  This is a great way to stir the room and get a higher level of engagement. I walk around listening to the ideas and figuring out where most students are in their learning.  

Discovery Activity

10 minutes

The purpose of this section is to raise the amount of ideas that students have about energy. To do this the students get out their lab notebooks and make two lists. The trick is to put the students under the right amount of time pressure that activates their thinking but doesn't shut them down.

The first list is titled, "Ways I have used energy today." To get students started on this list I model - thinking about my day and offering a small list of ways I used energy before I got to school. For example: 

-The alarm went off (sound, light energy).

-I took a hot shower (heat energy).

-I turned up the heater in the house (energy).

-I got dressed. 

Kids get the idea and start offering their own ideas.  At this point I tell them that they have one minute to list all the ways they've used energy so far today.

Once the kids have their list it is time to start on the second list, "What types of energy did I use?"

This time instead of modeling I ask one student to share a way they used energy. Generally, someone says something like, "I turned on the lights." Then I ask them to identify what that type of energy is. The kids will all say that it was electricity. At that point, I ask them to make a new list of all the different types of energy they can think of and tell them that I am giving them two minutes. 

This is a point where the students tend to naturally diverge. The category 3 students with very little idea of energy come up with only a few ideas. The category 1 students come up with many and varied ideas.  

Once the 2 minutes are up I ask all the students to stand up. I use the strategy, "The last one standing." I say, "If you have one type of energy stay standing. If you thought of two types of energy stay standing." I continue this until only one student is standing and then I ask that student to read their list. This is always interesting because invariably you will find some misconceptions to address. I put the types of energy on the board, breaking in only to correct any seriously egregious errors. Generally, the students are very engaged in this because they are trying to "bust" the "last student standing". It's important to keep this competition friendly and focused.  

Discussion

7 minutes

Now that students have a better idea of the concept of energy and some solid examples of energy uses and types, it is time to get to crux of the lesson, determining where the energy came from. The students again use their lab notebooks and we will be making flow maps. 

Energy, and its sources, are tough concepts to master. I model several examples for students before turning them loose. I like to start with an example that takes us back to photosynthesis. I choose one of the ways I used energy today as an example, walking into school. Then I trace back where the energy came from while making a flow map.  

Walking into school -----> food -----> sugar------> photosynthesis-------> sunlight! 

Here is a screencast of what this might look and sound like in class.

Unable to display content. Adobe Flash is required.

Once I've done a simple one, I'll look at a more complicated example.

Alarm clock----> Electricity----->oil---->dead plants and animals---->photosynthesis---->sunlight

Depending on the students, I might do several more examples getting help from the students along the way. At some point, the students are ready to work with a partner making their own flow maps. I walk around the class using praise-prompt-leave.

 Praise- prompt- leave is a strategy I use that sounds exactly like what it is.  You start by praising something in the student's work, prompt them with the next challenge, and the walk away.  The purpose behind this strategy is that it keeps a continuous level of rigor up by keeping the student working on the assignment as well as pushing that cognitive load back onto the students.  This is a great strategy to use if you see students doing work as quickly as possible.

A student work example is attached.  I like how this student traced the entire path.  It is also interesting the way she made a differentiation between plants and oats.  She did trace the path forward instead of backwards.  I'll have to do some more thinking on whether that is really important to learning or if either is fine. 

Closure

2 minutes

Closing Statement: "Today we looked at different types of energy and traced those all back to the sun.  Now we know that the sun is the source of most energy on Earth!"

Closing Question: We know that we get our energy from the food we eat like plants and animals.  Where do plants get their food from?  What substances do they use to produce energy?

For this closure, I'm choose to use one of the probes from Page Keeleys books, Uncovering Student Ideas in Science vol.1,2,3, and 4.  In this probe, "Is it food for plants,"  students are using the information they learned in the last unit to connect to the need for plants to produce energy. I've attached a student response below. This student response shows a moderate amount of understanding.  They have picked carbon dioxide and water from the list, but are also still listing soil as a food.  This is probably the most common misconception about plants students have.  The student also listed sunlight which makes me think that I need to continue identifying the differences between energy and matter.

Closure depends greatly on timing and is not as easy to plan in advance as opening.  You can find more information about how I manage closure here