Getting Food to The Cells (1)

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Students will be able to use a textbook to gather information about the structure and function of the organs in the digestive system.

Big Idea

Food and oxygen follow a path to get to the cells.

Ready. Set. Engage

5 minutes

Learning Goal:  Gather information about the digestive system and the respiratory system asnd how the body uses these systems to get food and oxygen to the cells.

Opening question: What parts in the digestive and respiratory system can you name?  

Students come in the room, get ready (get their stuff), get set (get settled in their seats), and engage in writing the learning goal and answering the essential question on the board.  I reward the students with Rock Star tickets.  

Today's question is a pre-assessment so I ask students about their answers to get a temperature on where we are with the learning.  I discover that students can name many of the parts, but don't necessarily connect parts with the big ideas.

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


5 minutes

I ask the students to write these words on post-it notes.  If you have a student assistant you can have this done in advance to save time.

Tissue - stomach lining

Cell - blood cell

Organ - small intestine

Organelle - nucleus

Organism - person

System - digestive

Atom - carbon

The students' job is to put these into order from smallest to greatest. I can walk around and see their thinking.  If I see major misconceptions I stop the class, do a mini-lesson, and then let them try again.  Today, I stop and do a mini lesson on the word atom.  Once I have done this, students are more successful with the task.


5 minutes

My focus now is to help students set up their notes and show them how to skim and scan.  I start this by having students get out their notebooks.  In my class, we keep all processing pieces such as, thinking maps, two-column notes, and picture notes in a notebook.  I have students make a giant stick figure on two different pages.  One is titled "Getting food to the cells - Digestive system". The other is titled "Getting oxygen to the cells - Respiratory system".

Then, I put the relevant page numbers on the board and make sure that each table has the right number of books.  I use our text book for this.  If you don't have a textbook you could use any reading that covers the structure and function of the organs in each system. A great free online source for texts is Ck-12. 

I tell the students that we will NOT be reading every word today.  (This usually gets a cheer!) Instead we will be skimming and scanning.  I model this strategy, sharing that I skim and scan using my background knowledge to pick out words.  For example, in the warm up today the students were supposed to list the organs of the systems they had heard of.  The first part I think of when I am thinking about food is the mouth.  So, I skim and scan the pages to find the section on the mouth.  Once I find it I read and take notes on the structure and function of the mouth on my stick figure sheet.  

Guided Note Taking

10 minutes

The strategy that students are going to use here collaborative and independent note-taking.

Just as I did in the Focus Section, I model my thinking, this time with the esophagus and the small intestine, stopping to ask kids questions about how we should find information and what information we should write down.  The students are expected to be helping find the information and record it in their notes.  I carry my text around with me so that I can make sure that students are completing this task.  I also use random questioning to pick students to help find the information, choose what is important, and help word it in the notes.  

Collaborative Practice

20 minutes

Working collaboratively is the focus now, as I stress that we are working together so that everyone has a chance to learn. To collaborate, they must communicate. And when they communicate, they have to process what they (think) they know into words, which increases the rigor of the activity as well as makes it more memorable.  I use these collaboration norms:

  1. Stay on Task.
  2. Listen to each other.
  3. Help others out.

The students are now expected to get the rest of the information on the digestive system and the respiratory system in their notes.  

I go around the room using a program like Class Dojo to keep track of the positive behaviors I am seeing.  

I record the behaviors on my tablet as I walk around the room.  Meanwhile I have the site pulled up on the computer up front.  This allows the positive comments to Pop-Up on the screen.  

Here is a screencast showing how use class dojo.  I find it a very powerful tool to encourage students to engage in the work.  

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Lab Set-up

7 minutes

Now I set up the lab demonstration (Crossing the Membrane) that we are going to do on the following day.  

I use this lab as a demonstration for two reasons. First, my projector was broken and I was teaching in the library and they didn't want me to do a student lab.  Second, I thought the ideas of the lab were simpler than the procedure and the students might have lost the big ideas if they started using the chemicals.

This lab is designed to show that large molecules like starch, will not pass through a cell membrane, while small molecules like sugar will.  The students have already made a connection to these nutrients in our discussion of the mouth. (The mouth contains chemicals that break down starch into sugar.)  This is a pretty simple lab to demo but a relatively hard one to do with students.  You should make your own decision on what is best for your kids.  

I simply get a beaker of water and add corn starch and corn syrup to it.  I make a little bag of dialysis tubing and just put water in it.  It is necessary to use really tight rubber-banding!  Place the dialysis bag in the beaker and wait for a day to see what crosses through the membrane.  In order to test this, you will need iodine and Benedict's solution.

For today, I simply present the students with the title and the purpose of the lab.  I have the students write their hypothesis and then I demonstrate the procedure by getting the dialysis tubing ready.


3 minutes

Closing Statement:  Today out learning goal was to gather information about the digestive system and the respiratory system and how the body uses these systems to get food and oxygen to the cells.  We did this be skimming and scanning texts and taking notes and we are preparing a lab for tomorrow. 

Closing Question: What is the path that food and oxygen takes to get to the cells?

Read more about effective ways to close your lesson, no matter how much time you have left!