BONUS EPISODE! Student-led Podcasts | Explore a Cell with Vancouver iTech Preparatory

Join me and some new friends as we shrink down and travel through a cell, checking out organelles along the way. It's a cell biology adventure!

This episode was written and performed by the 6th graders in Kelsey Starke's classes at Vancouver iTech Preparatory. Thanks to WSU's John Hinz for the expert factcheck.

Can't get enough cell bio?

• Check out the National Geographic cell biology collection
• Enjoy PBS Learning videos about life sciences
• Take a another trip through a cell with Amoeba Sisters
• Peep the National Science Foundation kids' video about cells

 As always, submit burning questions at askdruniverse.wsu.edu.  Who knows where your questions will take us next.

Transcript

Dr. Universe: Welcome back, friends. Today I get the amazing experience of shrinking with the first ever shrink ray here at iTech Prep. I will get to dive into the different parts of cells. 

Cells are tiny. Most cells in a person or plant are only about 10 to 20 micrometers in size. That's one-tenth the width of a human hair. Well, here I go.

Hello, tiny parts of cells, organelles, or whatever else you go by. I am here and excited to explore the extracellular matrix.

Students: Welcome to the extracellular matrix, or as we call it, the body's telephone lines. Let's start the tour. 

The ECM forms a network that gives tissues their structure and mechanical properties. The structure is a 3D network of proteins and carbohydrates that provides a supportive scaffold. It's on the outside of cells. 

The function of the extracellular matrix is to keep the tissue shape. It's also important for the connection.

Thank you so much for introducing me as the connection. The extracellular matrix connects the cell through proteins that span the inside and outside of the cell. They're transmembrane proteins called integrins.

Dr. Universe: Wow. There's so much to learn about the parts of a cell. Well, off I go to visit the cilia. Farewell, extracellular matrix.

Students: Bye!

Dr. Universe: Hello, scientists. This is the cilia, right?

Students: Yes. And did you want to know something cool? Cilia are kind of like brooms sweeping bad stuff off the cell.

Dr. Universe: That's very interesting. How are they able to do that?

Students: The cilia are like tiny hairs connected to the cell. The suck away all fluids and debris.

Dr. Universe: Interesting. What happens if the cilia suddenly disappear?

Students: Very bad things. Without cilia, the cell wouldn't be able to sweep away that garbage, potentially killing the cell. Some cells use cilia to move, so they would be stuck.

Dr. Universe: That's so awesome. Do you know anything else?

Students: Sadly not, but the cilia are extremely important organelles. They're very intriguing. Remember, biology is not for the faint of heart.

Dr. Universe: Hey, scientists talking to you from the cilia. Wait. I see a big, long, whip-like thing above me. What is that?

Students: Oh. Hi, Dr. Universe. That big thing you mentioned is the flagellum. The flagellum propels a cell through its liquid environment. The flagellum is important because it helps cells escape danger and move. 

The cell uses its flagellum like a tail. So the flagellum is technically like a tiny natural outboard motor or boat propeller.

Exactly.

Dr. Universe: How interesting. How about the structure of the flagellum?

Students: What a great question. It depends on the kind of cell. Some flagella have three main parts: a filament, a hook and a basal body. 

The filament is a long spiral tube shaped structure that extends from the surface of a cell and acts as a propeller for movement. And a hook in a short, flexible, tube-shaped structure that connects the rigid spiral filament to the rotary motor embedded in the cell membrane, which is the basal body. Other flagella have basal body and a shaft.

Dr. Universe: That's so interesting. Do all cells have a flagellum?

Students: No. Not all cells have a flagellum. Only bacteria, some archaea, some protests, and some eukaryotic cells, such as sperm cells do.

Well, that's all we have for you, Dr. Universe. Good luck getting inside the cell.

Dr. Universe: It looks like I have just encountered a solid barrier called the cell wall.

Students: That's right. Our job is to provide support and protection to a plant, so it acts like a central and protective layer. The cell walls thick, because its purpose is to be a protective layer for plant cell—like a mom protects their kids.

Oh, the cell wall has three layers that wrap around the cell and keep it safe. These layers are made of cellulose, which are long chains of sugar that act like strong fibers for extra protection.

Dr. Universe: How cool. Do all cells have this?

Students: No, not all cells only have this kind of cell wall. Bacteria and fungus have the cell wall just made of. Other animal cells do not have cell walls.

The cell walls main job is to provide structural support and shape to cells, and also protects them from mechanical stress and keeps them from bursting from excessive water intake. Cell walls help other cells by providing structural support and protective barrier, and a means for intercellular communication.

Dr. Universe: What is that thing over there?

Students: That is a cell membrane. All types of cells have cell membranes. It is like a gate that controls what enters or leaves the cell.

That's right. It could even be considered a bodyguard. And it works well with vesicles. Vesicles are like little transport bubbles that gather things from outside of the cell or releases waste from inside of the cell.

Hey, Dr. Universe. Here's another fact about the cell membrane. Did you know that cell membranes sometimes wraps around the material it brings in, holding it inside? It's like the cell is giving the material a big hug and then swallowing it.

Dr. Universe: Wow, I didn't know that. Can you tell me more about the function of the cell membrane?

Students: So the cell membrane is a protective barrier that controls what enters and exits the cell. It maintains the cell shape and integrity and allows for cell communication and tissue formation.

Yes, the cell membrane even separates and protects the interior of the cell from the outside environment or extracellular space.

Welcome to the cytoplasm. In cell biology, the cytoplasm is everything inside the cell—well, except the other cell parts.

Dr. Universe: Oh wow. This place is fascinating.

Students: Oh, yes it is. Did you know the cytoplasm is like the jelly like substance filling a cell that holds all the cells, parts or organelles in place. It is mostly water, salt, and other materials that the cell needs to function like structural proteins and enzymes.

Also, Dr. Universe, did you know that the cytoplasm is mostly water? It's about 75 to 80 percent water. And it is also important for holding all the other parts in place. Small molecules travel fast through the cytoplasm, and big molecules travel slowly. Isn't that fascinating?

Dr. Universe: That is fascinating. Good thing I'm small.

Students: It can have the consistency of both a liquid and a gel. A property known as sol gel behavior. It can even solidify to a gel like state when a cell is under stress. This allows some cells to temporarily shut down. This change protects the cell's internal structures until the nutrients are available again.

Dr. Universe: Oh! Whoa! That's awesome sauce.

Students: Well, it's the basic material by Dr. Universe. Have a good ride!

Dr. Universe: Whee! I am now in the cytoskeleton. Where are these young scientists who are going to guide me through the cytoskeleton? Hello?

Students: I'm a cytoskeleton. I provide a cell with a skeleton of protein fibers that maintains the cell's shape and allow things to move in a cell. The cytoskeleton is a network of protein that provides support to eukaryotic cells. It is made of three filaments microfilaments, intermediate filaments, and microtubes.

The cytoskeleton helps the cell keep its shape and keeps organelles in their spot. It's also like a highway. Vesicles and organelles can use the protein filament tracks to travel to other parts of the cell.

Dr. Universe: So I should probably use the cytoskeleton to see the rest of the cell. Huh?

Students: Yes, that is exactly what you should do. Also, fun fact the cytoskeleton contingent upon the cell is divided. Isn't that cool?

Dr. Universe: Wow. So cool.

Students: And welcome to the one and the only vacuole.

Dr. Universe: Oh, cool. Is there anything we should know before we go inside?

Students: Just be ready to step inside the vacuole. The vacuole is the main storage center, so there will be a lot of cell sap, waste, and water inside. The vacuole can take up most of the cell—sometimes up to 90 percent.

Dr. Universe: Can vacuoles be in any other cells? 

Students: Yeah, vacuoles can be found in plant, fungal, and sometimes animal cells.

Dr. Universe: What else does the vacuole do?

Students: Oh, Cora knows that. It holds water and waste and helps with digestion. It contains enzymes that help break down the waste.

Dr. Universe: How does the vacuole work?

Students: Together with other parts of the cell, the vacuole works with the cell wall to create turgor pressure, which keeps the plant strong. It works with the golgi apparatus to pack and transport proteins. It also partners with the cell membrane to control what enters and exits the cell.

Dr. Universe: Cool. Does it work with any other cell parts?

Students: Yes. And you're about to learn about that. Bye.

Dr. Universe: It looks like I have come to a lysosome.

Students: Welcome to the garbage can! That's what we sometimes call a lysosome.

Dr. Universe: Oh, really? Why do you call it that?

Students: In animal cells, the lysosome acts as the cell's digestive and recycling center by breaking down waste. So it collects the garbage like a garbage can.

Lysosomes work with the endoplasmic reticulum, Golgi apparatus, mitochondria and endosomes to break down their waste, too. In plant cells, the vacuole does this job. Dr. Universe, you should check out the peroxisome.

Dr. Universe: That's right. Let's get started.

Students: Peroxisomes are actually pretty cool. They are sometimes called the cellular detoxifiers. They are found in eukaryotic cells, including those of animals, plants and fungi. There isn't a single job title for peroxisome. It's an organelle, not a person. They break down fatty acids and make special lipids like plasmalogens that make up a cell membrane. Did you come through the cell membrane today?

Dr. Universe: Whoa, that's really cool. Tell me more.

Students: These cell parts can save lives, but they're actually really small, typically ranging from zero point one to one point five micrometers in diameter. Their shape and size can change based on what the cell needs.

Dr. Universe: I'm so glad we have these. Then do peroxisomes work with any other part of the cell?

Students: Yes they do. Peroxisomes work with other cell parts, including the endoplasmic reticulum. You will visit that part later. The ER and peroxisomes need to constantly exchange materials to make the lipids.

Now, here are some fun facts about the peroxisome. The peroxisome was once thought of as a permanent trash can. But now we know they are more specialized waste handlers.

Dr. Universe: They also seem like a recycling center, don't they? They break down fatty acids and amino acids and clean them up to be used again, converting them into useful materials for the cell?

Students: That's exactly right, Doctor universe.

Dr. Universe: Wow. This was very interesting. Thanks for that quick tour. Now time for me to go on to the chloroplast.

Students: Hello. We are here to give you helpful information about the cell parts called chloroplast, and we might share some helpful facts, too.

Dr. Universe: I can't wait to see what you guys have created.

Students: The chloroplast's primary job is photosynthesis. It captures light energy using chlorophyll, a green pigment, and uses it to power the changing of water and carbon dioxide into glucose and oxygen. It's kind of like a solar powered factory.

Dr. Universe: Oh, wow. That's so cool. Can all cells do this?

Students: No. Only plants, algae, and some protists and some bacteria.

Dr. Universe: I wish I could do that. Then I would never have to eat again.

Students: That would be cool, but, sadly, we can't. Inside of a chloroplast are stacks of things that look like discs called thylakoids. They're surrounded by a jelly-like liquid called stroma.

Dr. Universe: What are thylakoids? They sound very interesting.

Students: Thylakoids are structures that turn light energy into high energy molecules used to create the sugar glucose. They're like batteries that hold usable energy for a cell.

Dr. Universe: Wow. Thank you guys for giving us helpful information about an important plant cell part. But we still have many more parts to learn about.

Students: Welcome to the centriole, Dr. Universe. As you've noticed in the other parts you have visited, each organelle is directly related to its function.

Dr. Universe: Thanks for the welcome. I have noticed that. In that case, what does the centriole do?

Students: Centrioles help animal cells divide. They are sometimes called the cell's construction crew because they are like supervisors at a work site. They organize microtubules and sometimes form structures like cilia and flagella. Centrioles are paired in barrel-shaped organelles. They are located in the cytoplasm of animal cells near the nucleus.

Dr. Universe: How does its shape or how it's made help it do its job?

Students: Fantastic question. Its barrel structure is made up of microtubules, which are like hollow tubes. They help stabilize the cell before cell division.

Dr. Universe: Wow, that's so cool. I'm learning so much from this.

Students: Want a joke? Well, I've got one for you. Why are centrioles good at math?

Dr. Universe: I don't know. Why?

Students: Because they know how to divide.

Dr. Universe: That was a very good joke. Have a fantabulous rest of your day. Goodbye.

Wow. What is this awesome place?

Students: Hi. This is the mitochondria, the energy generator for the cell. I was just watching it make some energy.

We can tell you all about what the mitochondria does to help the cell and why it is, um—I forgot. Maybe he knows.

I don't know. Maybe she does.

I can tell you about what the mitochondria does. Mitochondria is a powerhouse for the cell. It breaks down food and turns it into energy for the cell. It is important because if we did not have it, we would die because the cells would have no energy to work. And if your cell don't work, would die.

Did you know that there can be one to two thousand mitochondria in one cell? There are low and high energy cells, too.

Dr. Universe: Wow. Thanks for telling me what the mitochondria does.

Hey, scientists. I just encountered an organelle and got inside of it. What is this cell part that I'm in?

Students: This is a nuclear envelope. And did you know that the nucleus is the control center of a eukaryotic cell?

A nuclear envelope's job is to act as a protective barrier. It separates the cell's genetic material from all the other parts of the cell, using tiny doors called nuclear pores.

An interesting thing about the nuclear envelope is that, in most higher level eukaryotic, it completely breaks down and then reforms every time the cell divides.

Dr. Universe: How interesting. I didn't know that. Do all cells have a nuclear envelope?

Students: The nuclear envelope is found in all eukaryotic cells, including animals, plants, fungi, and protists cells. These cells have a different nucleus enclosed by their nuclear envelope, unlike bacteria.

Dr. Universe: That's so cool. What job do you think the nuclear envelope would have in the real world?

Students: I think if a nuclear envelope had a human job, it would be a police officer, because it keeps the good things safe and the bad things out.

Dr. Universe: How creative. This was a great tour of a nuclear envelope. Thank you.

Hello, guys. I just got through the nuclear envelope and I can't wait to learn about the next part I encounter. Wait, where are we?

Students: Oh, we are in the nucleus, and we are here to figure out how it works and why it is there and why it needs to be there. Follow us and see the wonders of the nucleus.

Dr. Universe: Oh, I'm so excited to be here. I wonder how it works.

Students: The main job of the nucleus is to hold the DNA and keep it safe. It acts like the cell's control center, protecting the cell's DNA. If the nucleus stopped working, the cell would eventually die because it wouldn't have instructions. Also, it is usually only 10 percent of the cell, although it can be bigger or smaller in some cells.

Dr. Universe: Wait, so there's only DNA in the nucleus?

Students: Actually, there is an interesting part of the nucleus called the nucleolus. You'll visit that soon. 

But before you go. A fun fact about the amazing and complicated nucleus is that nucleus is way smaller than a grain of sand. You can line up about 80 cell nuclei across one grain.

So that's all. Bye, Dr. Universe. I hope you learned a lot about the nucleus and how it works.

Hello, doctor universe, welcome to the DNA. I will be telling you about how the DNA works.

Dr. Universe: Thank you. I'm excited to learn. What does DNA do?

Students: DNA provides instructions. It's like a blueprint for making proteins. Proteins are molecules that build, repair and carry things. They also do a bunch of other cool jobs.

Dr. Universe: That sounds important. How does DNA do this?

Students: DNA holds the genetic code in a double helix, which looks like a twisted ladder.

Dr. Universe: Sounds interesting. Tell me more.

Students: Did you know that we share around 40 to 50 of our DNA with cabbage?

Dr. Universe: Are you telling me I'm 50 percent the same as cabbage?

Students: Well, thanks for showing me around the DNA.

Dr. Universe: Hi there, young ones. Now we're in the nucleolus. How cool is that?

Students: Hello. Welcome to the nucleolus, Doctor universe.

Dr. Universe: Thank you. We have some very exciting things to learn about.

Students: Yes, we do. The nucleolus is a ribosome factory. It also acts as a stress sensor. Sometimes viruses target it. Have you been to the ribosome yet?

Dr. Universe: No, not yet, but I can't wait till I do. How does it make ribosomes?

Students: Well, a ribosome is made of two subunits, so it has to make both of those in order to do that. It has three main components: the fibrillar center, the dense fibrillar component, and the granular component.

Dr. Universe: Why does it need three compartments?

Students: Each component is a different stage of ribosome production.

Dr. Universe: Thank you for helping us learn about the nucleolus. Stay science-y.

Now that I'm out of the nucleus, I really hope I encounter a ribosome like the last group just told me about. Oh wait, I think here is one now.

Hey, little scientists, what does a ribosome do?

Students: Well, the function of the ribosome is to make proteins by reading the genetic instructions from the messenger RNA and linking blocks of amino acid together to form long protein chains.

Ribosomes are attached to rough endoplasmic reticulum, or RER. RER modifies the protein that the ribosomes make.

So, ribosomes are essential molecular machines. They read the genetic code and assemble the proteins. Proteins do everything in the cell, so ribosomes are essential.

Dr. Universe: That's so cool. Thanks, little scientists. Now let's move on to the next part.

Look at that structure with all those ribosomes on it. Let me talk to this scientist and ask. Hello there. What is this?

Students: Hello, Dr. Universe. This is a rough endoplasmic reticulum.

Dr. Universe: I wonder what a rough endoplasmic reticulum is and why it's called that.

Students: I wondered that, too. Let's take a look around it. It's kind of like a network of sacks with small lumps on the sides. Those lumps are ribosomes that are studded around the outside of it.

Did you know that the our job is to make proteins? It's kind of like a factory. It makes proteins, modifies them to the right standards, then sends them off.

Dr. Universe: That's so cool. But why does it need ribosomes on the outside?

Students: The ribosomes on the outside helps to all eat all and make proteins. And those proteins can enter the RER to be folded and modified.

The RER sends the protein to the Golgi apparatus for further modification. They send it there because the Golgi apparatus sorts and tags the proteins by adding sugars and phosphates to the proteins.

Dr. Universe: That's pretty cool. Thanks for showing me around. However, I need to research some more cell parts. Until next time.

Hey there, young scientists. I'm very excited to explore the part of the cell called the smooth endoplasmic reticulum.

Students: We're excited to talk to you about it. The smooth endoplasmic reticulum is the opposite of a rough endoplasmic reticulum. It is found in plants and animal cells.

Yep. And its structure is made up of a network of interconnected ribosome-free tubules and vesicles within the cytoplasm. It's basically a big tube.

Wow. Its function is to make fats and hormones store calcium and to clean up toxins. Then it takes those things it makes and packages them up and sends them to the Golgi apparatus. Think of it like an Amazon distribution center.

So there you have it. All the information you could possibly ever want to know about the smooth endoplasmic reticulum.

Dr. Universe: Wow. That was very cool. Well, I believe that's it. Thank you, young scientists.

Students: You're welcome.

Dr. Universe: Hi, everybody. I just came from the smooth endoplasmic reticulum. It was amazing to learn about. But I'm really interested in learning about the Golgi apparatus.

Students: Hello, Dr. Universe. Today we will be talking about the Golgi apparatus, also known as the Golgi body. The Golgi body is found in eukaryotic cells like plant, animal, fungi, and protists cells.

Dr. Universe: Very interesting. Can you tell me more about the job of the Golgi apparatus?

Students: Okay. Great question. The Golgi apparatus is like a post office. It packages things like lipids and proteins to be sent off to other parts of the cell. Before sending them off, it checks for any mistakes and takes unnecessary parts off if that's needed.

Dr. Universe: Amazing. Now, I would like to learn about the structure of a Golgi apparatus.

Students: The structure of a Golgi apparatus is very unique. It looks kind of like a stack of pancakes that you can put syrup on and eat. This material is called cisternae. It can be different sizes depending on the type of cell and what the cell does. The special shape of the Golgi apparatus helps it do important work inside the cell.

Dr. Universe: That is really cool. I love pancakes. Does the Golgi apparatus work with any other cell parts?

Students: Yes it does. It works closely with the lysosome, which you've already visited. It actually helps make the lysosome.

Dr. Universe: Oh, wow. I feel like I know so much more. Is there anything else I should know before I go?

Students: One fun fact about the Golgi body is that its existence was only confirmed with electron microscopes in 1954.

Dr. Universe: That was really interesting. Thank you for your time.

Hi. Who are you guys?

Students: Hello. We are the vesicles. We're part of a cell. We could transport things. Kind of like a train or a car.

Yeah. Transport vesicles move enzymes, hormones, and structural proteins. We help recycle waste and transfer things. We often move on a kind of railroad tracks that are actually called microtubules. I think you learned about microtubules in the cytoskeleton doctor universe. What brings you here?

Dr. Universe: Oh, I just came from the Golgi body. And this is my last stop because you guys can sent me out, right?

Students: Yeah. We're like mini trains for the body. We also work with lysosomes, the endoplasmic reticulum, the Golgi body, and the cell membrane.

Dr. Universe: That's all very cool. But you guys do so much. From what I know, when that happens, there are more than one type.

Students: You're right. We do have many forms. Transport vesicles move things around, secretory vesicles move things out of the cell, and they are crucial for healthy organs and tissue function. There are a few more, but to keep it short, That's it.

In the self-contained structure, consisting of fluid or gas, surrounded and enclosed by a membrane built like all the other membranes seen in the cell, the lipid bilayer is made up of hydrophilic heads and hydrophobic tails that cluster together.

Oh, it's almost time for you to go.

Well, it's time for your departure from cell. I hope you had a great time. We'll hand you off to the transport vesicle now. Bye.

Dr. Universe: Thank you for taking me on this adventure. I hope to see everyone again.

That's all for this episode, friends. As always, if you've got a science question for me, you can submit it at askdruniverse.wsu.edu. That's a s k d r u n i v e r s e dot w s u dot e d u. Who knows where your questions will take us next?