How to teach the parts of a cell

Why this matters

A student can label every part of a cell diagram and still not know what any part does. Asked why a runner's legs give out, that student picks the nucleus, because a worksheet called it the control center. The labeled diagram looks finished, and the teacher has to wait for quiz day to find out.

Cell organelles and what they do

Organelles are the structures inside a cell that each do a job. The 3D cell in the Flint activity has a button for each of these eight (OpenStax Biology 2e):

• The nucleus holds the cell's DNA and directs the making of ribosomes and proteins.
• Ribosomes make proteins.
• The rough ER has ribosomes on its surface and makes proteins for membranes and for the cell to send out.
• The smooth ER makes lipids.
• The Golgi apparatus modifies the proteins and lipids made in the ER.
• Mitochondria make ATP, the energy the cell uses.
• Lysosomes use enzymes to break down waste, including worn-out organelles.
• The cell membrane controls what moves into and out of the cell.

In the Flint activity, each student gets a patient written around their own sport and finds the failing organelle by spinning and clicking the 3D cell. A labeled worksheet doesn't show whether a student knows what each part does. A student who guesses the nucleus for a patient whose muscles run out of energy gets a hint from Sparky, Flint's AI tutor, that sends them back to the 3D cell, and a student who finds the mitochondria gets a harder case with a narrated video.

Jordan's chat: a runner whose legs give out mid-5K

Jordan runs the 5K for the school cross-country team. Jordan can label a cell diagram but doesn't yet know what each organelle does.

The whole class gets the same activity: the same greeting, the same 3D cell and the same two organelles to find. Each student's chat is their own. Sparky asks about their sport, writes the patients around it, and its next message depends on what they just wrote.

Sparky uses the student's sportSparky gives a hint instead of the answerA right answer gets a harder case

J

Jordan

Interest: Runs the 5K for the school cross-country teamStarting point: Can label a cell diagram, not yet what each part does

Sparky

Hey there, future doctor! I've got two medical mysteries for you to solve today, and your only clue is a 3D animal cell you can spin and click. Before we dive in, tell me: what sport or activity do you love?

Jordan

cross country. i run the 5k for my school team

Sparky

Love it, a 5K runner! Here's your first case. Your patient is a dedicated cross country runner, just like you. They're in great shape, but after just a few minutes into a 5K, their muscles completely give out. Doctors find that the muscle cells can't produce enough energy. Spin the 3D cell, click around, and tell me: which organelle do you think is failing, and why?

Jordan

the nucleus? my worksheet said it's the control center so if it breaks nothing in the cell works

Sparky

Good thinking connecting it to the control center. But the nucleus controls the cell's instructions, not its energy production specifically. Take another spin through the 3D cell. Which organelle is actually in charge of making energy for the cell?

Jordan

oh wait its the mitochondria. they turn food into ATP, so if they cant make enough ATP the muscle cells run out of energy and the runners legs give out

Sparky

Exactly right. The mitochondria are the cell's power plants, and when they fail, a cross country runner's muscles can't keep going. The real condition is called mitochondrial myopathy.

Sparky

Here's your second mystery, and this one's a tough one. A young child who loves watching cross country races starts losing skills they used to have. They can't move well or see clearly. Doctors find that fatty waste is building up inside their nerve cells and can't be broken down. Watch the video for a clue, then tell me: which organelle is failing here, and why does the waste build up?

Jordan

the lysosomes. in the video they use enzymes to break down waste, so if one enzyme is missing the fat cant get broken down and it just piles up in the nerve cells

Sparky

Brilliant diagnosis! The lysosome is the cell's cleanup crew, and when one enzyme is missing, that waste has nowhere to go and builds up. The real disease is called Tay-Sachs disease.

Understanding check

You solved both cases, and in each one, just one organelle was failing. Why did that make the whole person sick?

Jordan

because the muscle is made of cells, so if all the cells cant make energy the whole muscle stops working

Sparky

Great start, you're on the right track with the muscle. Think about both cases: what happens when nerve cells can't clean up waste, and how does that connect to the whole body breaking down?

Jordan

the nerve cells fill up with waste so they stop sending signals, and then the kid cant move or see because nerves control that. so cells make tissues, tissues make organs, and if one organelle fails in a lot of cells the organ fails

Sparky

That is an outstanding answer. Organelle, cell, tissue, organ, whole body: one tiny failure cascades all the way up.

Found the mitochondria after one hint, then diagnosed Tay-Sachs disease without one

Jordan's first guess was the nucleus, the part a worksheet called the control center. Sparky didn't name the right organelle. It said the patient's problem was energy and sent Jordan back to the 3D cell, where Mitochondria reads "converts nutrients into ATP energy." The harder case came only after Jordan explained the energy link, and Jordan solved it from the video. Jordan's first answer to the last question covered only the runner, so Sparky asked about the nerve cells too.

Jordan is an example student, and Sparky's replies are shortened. Both conditions are real: mitochondrial myopathy causes muscle weakness and exercise intolerance, and in Tay-Sachs disease a missing lysosome enzyme lets a fatty substance build up in nerve cells.

What Flint did for Jordan

• The activity opens with a 3D cell Jordan could spin and click, so Jordan checked what each organelle does instead of guessing from a worksheet.
• Sparky wrote both patients around cross-country running, Jordan's own sport.
• When Jordan guessed the nucleus, Sparky gave a hint that sent Jordan back to the 3D cell instead of giving the answer.
• After Jordan named the mitochondria, Sparky made a 52-second narrated video on how a cell breaks down waste, without naming the organelle, for the harder case.
• When Jordan's last answer covered one case, Sparky asked a follow-up about the other.

A teacher can't do this by hand for 30 students, and Sparky does it in every student's chat.

Who guessed the nucleus, and who solved both cases

When students finish, Sparky grades each chat against the activity's rubric: identifying the organelle from symptoms, explaining what it does, and using hints to revise. The activity page shows who needs help right now, what the class does well, and what to practice next.

Set up the activity for free

The broken organelle activity is in Flint's public library, with Sparky's guidelines, greeting, 3D cell and a rubric already written. Open it, select Use activity to copy it into a free Flint account, and move it to a class. In the activity's Preview tab, select Try session myself to test the activity as a student before you assign it.

For more science activities, see Flint for science.