Alabama STEM explores is made possible by the generous suppor of Hudson Alpha Institute for Biotechnology Southern Research Solving the World's Hardest Problems, the Holle Family Foundation, Alabama Works.

Alabama STEM Council.

Alabama Mathematics, Science, Technology and Engineering Coalition.

Alabama Math, Science and Technology Initiative.

I'm home.

Two different colored tomatoes closely that very often.

I wonder why they're different colors.

Do they make them this way on purpose.

Let's find out.

Come on.

Hi, and welcome to our newest episode of Alabama STEM Explorers.

I'm Anderson.

And I'm Katherine, and we're coming to you from Southern Research in Birmingham, Alabama.

I was just doing Katherine, about my tomatoes.

I don't know why they were both different colors That's a really good question, Anderson.

And lots of fruits and vegetables have a variety of colors.

And so what we have in front of us is we have a two platters full of fruits and vegetables.

What's the first thing that you notice?

Um, they're all different colors.

That's right.

There are different colors.

And the colors come from a chemical molecule called a pigment.

Have you ever heard of that pigment before?

Yeah.

Yeah.

What do you what do you think of when I say pigment colors?

Yeah, that's right.

And so when you look at this platter, you see a lot of colors.

It kind of looks like when you go to the grocery stor and you walk in the produce aisle and it's so beautiful with all of the colors.

But so I've represented three different categories of pigments.

So if you look right here, we have some romaine lettuce, some broccoli and some spinach.

The pigment that makes those colors green is the pigment called chlorophyll Have you ever heard of Corvo before?

I don't think so.

Yeah.

So chlorophyll is a pigment.

Usually you might hear it when you think about photosynthesis in plants.

Yeah.

Yeah.

And then we also have another pigment anthocyanin and that's going to give the red, the blue and the purple color.

So the purple cabbage and the grapes and the blueberries and then the pigment that we are going to talk about today is called a carotenoid.

And that pigment gives yellow and orange and red fruits and vegetables their color.

Does that make sense?

Yeah.

I wonder how are pigments made?

That is an excellent question, Anderson.

There is a lot of really cool chemistry and biology happening to make these pigments.

And so let me ask you this.

Do you like tacos and burritos?

Of course he does it.

I exactly.

I love me a good taco.

I love going to my favorite Tex Mex restaurant.

So I want you to imagine you walk into your Tex Mex restaurant.

And what do you see?

You have the assembly line, right.

And each worker has a specific job or function to do in the restaurant.

Are you following?

Yeah.

So kind of like this diagram back here.

And so when you walk in, you start with a soft taco shell.

And that first worker, their responsibility is to add the rice or the beans to the taco shell.

And then they pass that along in the next person as the tomatoes, the lettuce, the cheese.

And it continues on to the point where maybe the next to the last person is going to fold that shell into a taco.

But they could take it one step further and they can keep on folding and make it a burrito.

Does that make sense?

Yeah.

OK, so pigments are made in a very similar way.

But instead of workers, we have what's called an enzyme And so these enzymes help this process of pigment synthesis.

So some enzymes might add things to our molecule and some enzymes might take things away.

Some enzymes might rearrange the molecule or change the structure.

And ultimately, the structure of that chemical compound is what is going to give us add the color that we see in our fruits and vegetables.

Does that make sense?

So the main point is that each enzyme has a different role or a different function.

And if one enzyme is sleeping, then you might not end up with the color that you were expecting.

Are you following still?

Yeah, but how do enzymes know what their jobs are?

That is an Adobe.

Yeah, that is an excellent question, Anderson, and I'm so glad that you asked that.

So just like our workers in our assembly line, they have a set of instructions that tell them how to fold the burrito or how to add the lettuce and the cheese and what order enzymes have a similar set of instructions.

And that is found within your DNA or within the DNA of the plant cell.

All right.

And so here I have a model of DNA.

Have you ever heard of DNA before?

Yeah.

Yeah.

What do you know about DNA?

I know that DNA helps make us.

Yeah, that's right.

And so DNA is found in everything alive.

And do you think is it is like a recipe?

It is a recipe of life.

Interesting.

Do you like to cook?

I do like to cook.

Yeah.

What do you like to cook?

I like making brownies.

Oh, I love brownies.

I do follow a recipe when you cook.

Yeah, I follow my grandmother's recipe.

But she's really protective of her recipe.

Oh, yeah, I bet.

So just like the recipe that Anderson uses to make his brownies and DNA is a recipe that tells ourselves how to behave and what to do.

So the DNA might tell this squash that it is going to be a yellow squash.

Right.

And so interesting.

Do you ever change your recipe?

I do, yeah.

One time I accidentally use salt instead of sugar.

Oh, that is something you definitely do not want to try at home.

And that made some nasty brownies.

It was very gross.

Yeah.

So just like changing a recipe and a brownie mixture, changing the DNA recipe can sometimes lead to negative effects.

So maybe it would make our tomato kind of puny and not taste good or sour, or it could also lead to some beneficial.

Outcomes like maybe it makes the tomato more resistant to a drought.

Does that make sense?

Yeah.

OK, cool.

So this is our DNA model.

But like your recipe, you said your grandma is very particular, right?

Yeah.

So your grandma does not let that recipe leave her house is that what you're saying?

Never leave the house.

And so similar to that, here is our DNA.

And our DNA is found within the nucleus of the cell, but it cannot leave the nucleus.

And so we've got to make a copy, just like Anderson has to make a copy of that brownie recipe.

We need to make a copy of our DNA recipe.

And the way that that works is we also have another molecule called RNA.

So here's our RNA molecule.

And what do you notice the difference between the two?

This one's straight.

Yeah, this one is straight is just one strand where this one has two strands.

But the point is, this is a copy.

And this copy, just like the copy of your recipe, is going to lead us to make a protein or an enzyme.

So the enzymes that are responsible for for making those pigments that make these different colors.

That is what we're talking about.

And so this message, this RNA is going to travel outside of the nucleus, just like you would travel your recipe outside of grandma's house.

And it is going to take it to the ribosome in the ribosome is my favorite part of all of biology, really in the ribosome is responsible for making protein.

And the way it does that is it takes different amino acids.

So here are these are each of these blocks represents a different amino acid, and it is going to link them together based on the sequence of the RNA.

All right.

And then it's going to fold it into a protein So this is like a protein.

It's kind of a model.

Yeah.

So this is actually a model of the protein that creates that red pigment, which is called lycopene in red tomato, but red tomato and orange tomato or different.

Right.

And that was your question is why are red tomatoes red and orange tomatoes?

Orange.

Exactly.

Yeah.

And so the difference comes down to the pigment.

And so in red tomato, it has a lot of lycopene.

And an orange tomato has a lot of pro lycopene.

So we'll grab our orange and our red tomato.

But why does red tomato have lycopene and orange tomato had pro lycopene?

All right.

Good question.

So let's think back to our tex Mex analogy.

So if you think back here, you wanted a burrito, right?

Definitely.

Yeah.

Well, let's say that this person right here, they folded into a taco within the last person who was responsible for folding it into a burrito.

Their set of instructions was wrong.

So the boss gave them their instructions and it said 9:00 p.m. when it should have said 9:00 a.m..

So they were not there when you wanted to order your burrito.

And so you ended up with a taco.

Right.

Right.

So this works very similar.

So the enzyme that is responsible for making the pigment that is red, the lycopene.

There is a mutation or a change in the instructions, a change in the DNA that makes that G or that that enzyme not work.

And so whenever it doesn't work, you end up with an orange tomato.

So just like if this person was not there, you would end up with a taco, which is still delicious, but is not quite a burrito, just like a orange tomato is still an orange tomato.

It is delicious.

A final product, but it is not a red tomato.

Does that make sense?

Yeah.

Yeah.

So the the instructions that vary are found in its recipe, which is found in the DNA.

So this is actually the instructions to make to the instructions for the enzyme that makes these pigments, the certain colors.

That instruction recipe is really long.

It's like hundred letters.

Eighteen hundred nucleotides long.

But within that recipe, there is one change, one letter change, which causes the entire recipe to to make that enzyme that converts your your pro lycopene to your lycopene, not to work.

All right.

So one letter change in eight hundred.

This molecule right here, this is for our red tomato.

And this is only 12 of those letters.

This is a 12 nucleotide stretch.

This is for our orange tomato, 12 nucleotides stretch.

Can you find the difference?

Tell me if you can find the difference between the two.

Hmm Which base is different, which bases pairing?

I can't tell.

Maybe.

Yeah.

Yeah.

Yeah, that is exactly right.

So in that that gene that is eight hundred nucleotides long, one letter has changed, which made that recipe make the enzyme not work.

And so what happens is, as it goes through this process of of copying the instructions from the DNA to the RNA to the amino acid to the protein, that one letter change is going to change a single amino acids.

You guys can see the difference between those four amino acids.

So this one is different and this one is different.

And then in the end, whenever you are folding your protein, it is going to fold it in a different conformation, which is going to inactivate that enzyme and it is not going to work.

And that, ladies and gentlemen, is how or why you have an orange tomato and a red tomato.

Wow.

Hi, my name is Caden and I was wondering, how do x rays take pictures of our bones?

Good question.

Interger of photons, visible light is about three point one electron volts like weakly tossed balls.

Most photons of visible light bounce off your skin, but x ray photons carry about 100 to 100000 electrons volts and go right through the scan.

An x ray being passes through your body.

The body tissues and bones absorb and or block the beam in varying amounts dependent on its density.

This creates a shadow that is picked up on theam or a sensor placed on the opposite side of the beam, much like when you hold a flashlight up to your hand and cast a shadow on a wall.

Mineral rich bones and teeth are much denser than skin.

So instead of traveling through, they are absorbed.

The result, an image of the film showing the bones.

So I guess originally when I got hired on, we had several clinical projects going on.

The majority of them are geared towards enrolling pediatric patients into our studies.

And what we're hoping to do is identify the cause of whatever rare disease they have So they might have seizures or they might have some other like intellectual disability or developmental delay.

And we try to figure out what's causing that.

Now, I've also kind of learned the analysis part because me and I like to learn as much as I can.

And I had some free time.

So I got the other people in our group to teach me how to analyze genomes.

So I also analyzed genomes more so lately.

That's shifted back towards doing more studying enrollment, because we've been able to bring on more studies and I've had to spend more my time doing that.

So I grew up in a family full of nerds.

We all really love science and math.

My mom was a mathematician and my dad is a physicist.

I remember when I was really young, maybe like four.

They would set up these mirrors across the house.

We turn off all the lights and we would stand at a doorway with a flashlight and try to make the light bounce back to where we were.

So we would learn about reflection and refraction.

Cooking turned into a science experiment.

It was always something that we were learning.

And so that kind of made me reassured me that I was interested in science.

When I started going to college and getting into that realm people said, oh if you like science and math, you should be a doctor.

It was just the go to.

So I followed the path that I thought I should go down.

And I did all the premed stuff and applied for medical school and did all of that.

And I went and also shadows a bunch of physicians and doing that, I had tons of questions about the medications they were prescribing or the therapies that they were using, why I gave this drug over that drug.

And they were saying, you know, you have a ton of questions about mechanistic things.

Perhaps you should look into grad school instead as well.

So I went ahead and applied for grad school and it was a great fit.

You ask a question and you get a chance to interrogate that in real time and come up with answers on your own.

And so that kind of was the path that inspired me.

And then I love that, because now I'm able to kind of apply those skills, ask those questions, you know, in different venues, and never really get bored with your job, because there's always a good question to ask.

And there's always a good thing to figure out.

Hi, I'm Neil.

And this is Nilah, and we're here at the Hudson Alpha Institute for Biotechnology.

And today we're going on a treasure hunt.

Have you been on a treasure hunt before?

Have yes.

You found the treasure?

Yes.

So you would consider yourself a pretty good treasure hunter?

Yes, I'd consider myself a pro.

All right.

So today our treasure is DNA.

OK, can you tell me what you might know about DNA?

I know that it is in a double helix and like a twisted ladder And it stands for deoxyribonucleic acid.

Exactly.

So DNA is a recipe.

And we'll talk more about recipes in just a second.

But first, if we're going to do a treasure hunt, we need a map to tell us how to get to the treasure.

OK, here is our map.

Hmm.

You think you can follow this through?

Yeah, I think so.

I think you can do.

So this is a model of a plant cell and it contains all the pieces that you would find inside a typical plant cell.

OK, we're going to have to use this as our set of instructions Here is where we want to go.

This is the DNA.

It's inside the nucleus.

It's surrounded by a membrane made of fat with another membrane made of fat and then a hard sell wall.

So we have to break through the cell wall, through the cell membrane, through the nuclear membrane and get to the DNA.

OK, we want to get rid of all the rest of this.

So what I love about this activity is that you can do this at home with things you probably have in your kitchen.

So this really cool, high tech DNA molecule, we can see with stuff that we use all the time.

We're going to look at the DNA of a strawberry.

OK, so step one, pick whatever.

Strawberry strikes your fancy.

I'm going to use this one.

That's a nice look.

And strawberry.

Go ahead and put it in one of those Ziploc bags and then seal it.

And you are going to smash it.

You're going to mash mash it to pieces.

What Nilah is doing is actually breaking the hard cell wall and she's pulling the cells apart one from the other.

Do you have a guess how many cells are in that strawberry?

I'm going to say one million.

You're absolutely right.

Somewhere between one and two million cells in that strawberry.

And what you're doing right now is breaking the cell wall.

So as you continue to mash, I'm going to start talking about step two.

We're going to use this liquid, which is called a buffer.

And a buffer is simply a set of chemicals mixed together in a liquid.

In this case, it's water.

OK.

So you can go ahead and that looks good.

Open up your bag and pour the buffer in and then keep on mixing.

This buffer is made of dishwashing soap, salt and tap water.

If you want to try to make this on your own, you'll take about a cup of water, a tablespoon of soap and a teaspoon of salt, and you'll mix them all together.

And then you'll use three tablespoons, which is about 15 mils for our experiment.

Nilah I would imagine that you help out and wash the dishes.

Yes.

So when you wash the dishes, if you've got a dish that has a lot of grease on it or you've got grease on your hands, how do you get that grease off?

I wash my hands or the pot with soap and water.

Exactly.

And there's soap in our Liszt's buffer.

And the soap actually surrounds the grease and pulls it away from your dish or from your hands.

Or in this example, it actually pulls holes in our cell membrane so that the cell contents actually leak out into the bag so that we can get through our cell membrane and through our nuclear membrane down to where that DNA is.

OK, so you're going to keep on it mashing that up.

It's kind of like a strawberry smoothie at this point.

All right.

Now we've got to separate out the seeds and the leaves and the other pieces from the liquid, which has our DNA.

So you can grab one of those high tech filtration devices right over there.

This is a plastic cup, a coffee filter and a rubber band.

And so we're essentially just going to pour that content of the bag into this cup.

Great work, you can just set that bag off to the side, and we should there we go.

We should be able to start to see the liquid seep through the filter, the seeds and the leaves and the pulp are going to stay up here.

And this is what we want.

So I'm going to set that aside for a second.

Let's talk about the fact that DNA is a recipe, Nyla.

You've already told me that you like to cook.

Yes.

What are some of the favorite things that you cook?

I like to make pancakes and spaghetti together.

Spaghetti.

Spaghetti on pancakes?

No, no, no.

Not together.

Separate separate pieces.

OK, I just just checking .

So when you make pancakes, you follow a recipe, right?

Yes And that recipe gives you instructions for how you mix things together and then what you do to get yourself pancakes.

Yes.

DNA is like that.

DNA is a set of genetic instructions that tell cells how to make all the things that they need, not pancakes and spaghetti, but the proteins that they need to do their job in this case to be maybe a fruit cell or a leaf cell or a root cell.

It's that set of information and instructions.

So now we've let the liquid filter through.

OK, you picked a great strawberry.

We have an awful lot of liquid to work with.

We can't see the DNA in here.

The DNA has is dissolved.

It's soluble in our water based solution.

OK, so we need something that DNA won't dissolve in in order to make our DNA visible.

And for that, I have a mystery liquid.

Hmm.

All right.

What do you think might be in here?

Oh, I think it's water.

If I told you I put this in the freezer overnight would still be liquid water.

No, it have some ice chunks.

All right.

So it's not water.

Let's gently let you smell some of it.

It's it's rubbing alcohol.

It has a really strong smell.

Doesn't smells like the doctor's office.

Yeah.

It makes you think maybe of going to to see the doctor.

Yeah.

All right.

So rubbing alcohol, DNA does not dissolve in rubbing alcohol.

This is alcohol that you just buy at the drugstore.

This is not the alcohol that people drink.

And it's really, really cold.

I want you to pour this cup into the tube and then let's take a look at what happens.

Well, we almost ran over there well, all right.

OK. Take a look at this.

OK, hold on to it and tell me what you see beginning to happen.

I see bubbles forming at the top.

And I also see like red strings going to the top, almost like a red cloud.

Yeah.

All that fluffy piece right there, that red cloud.

That's the DNA from those million strawberry cells.

And it's got air bubbles because when you pour poured it into the alcohol, it added mixed up in air raid and it added some air.

Yeah.

Let's actually get a closer look at that.

So take one of these sticks and just set it down right in the cloud and then just twirl it just in the cloud.

All right.

Whoa.

Yeah.

Yeah, that is the DNA from all of those cells of our strawberry.

I pull it all the way out here.

I'll take one.

Yes, you can touch it if you want.

What's it feel like it feels like slimy.

Yeah, it's a little slippery, yeah, isn't it?

It's it's not it's not rough.

So the process of what you and I have just done is exactly what happens if we were to take our DNA, if we were to go to the doctor and have a blood sample and they needed to take our DNA.

Now, they wouldn't use dishwashing soap and coffee filters, but they would break the cell open, they would separate out the key contents, and then they would make the DNA visible.

That's the instruction book for those strawberries.

Pretty cool, isn't it?

Yes.

Yeah.

Nice work, Nilah Again, this is something that you can do at home.

I hope that you enjoy the activity.

DNA is an incredible molecule.

Yes, it sure is.

Hi, I'm Morgan, and I'd like to know where our fingers get wrinkled when we put them on the water.

The distinctive wrinkling of skin on our fingers and toes after they've been in water for a while is caused by blood vessels constricting below the skin.

Scientists theorize that the treads created by thos wrinkles were an adaptation preserved from our evolutionary past allowing a better grip when wit laboratory tests confirmed the theory that wrinkly fingers improve our grip on wet arzamas objects working to channel away the water like rain treads in car tires.

Thanks for watching.

Alabama's STEM Explorers.

If you missed anything or you want to watch something again, you can check out our website, Alabama STEM Explorers dot org.

Maybe you have a question we could answer here on the show and you might grab a cool T-shirt.

Feel free to send us a video question or an e-mail on our Web site.

Alabama STEM Explorers dot org.

Thanks again for watching.

We'll be back next week.

Alabama's STEM explorers is made possible by the generous support of Hudson Alpha Institute for Biotechnology, translating the power of genomics into real world results.

Southern research solving the world's hardest problems.

The Holle Family Foundation established to honor the legacy of Brigadier General Everett Holley and his parents, Evelyn and Fred Holley, champions of servant leadership Alabama works a network of interconnected providers.

Connecting business and industry needs to a highly skilled and trained workforce.

Alabama STEM Council dedicated to improving STEM education, career awareness and workforce development across Alabama.

Alabama Mathematics, Science, Technology and Engineering, Coalition for Education, advocating for exceptional STEM education in Alabama.

Alabama Math, Science and Technology Initiative, the Alabama Department of Education's initiative to improve math and science teaching statewide.