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Hank and PhD candidate Casey Massena go deep into the chemistry of a molecule that Casey helped create! Then Jessi joins the show to show off Ecuador, one of her many conures!

Casey's paper:

Special Thanks to the Department of Chemistry and Biochemistry at the University of Montana and the Orion Berryman Research Group!

Animal Wonders:

Hosted by: Hank Green
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 (00:00) to (02:00)


H: Hello, and welcome to the SciShow Talk Show.  It's that day on SciShow where we talk to interesting people about interesting stuff.  Today, we're talking to Casey Massena from the University of Montana, who has done some amazing--what, like feels like blending between organic and biochemistry to me.

C: Yeah.

H: A little bit.  So what's your background?

C: I actually have a liberal arts degree, but um, feel in love with chemistry, especially (?~0:33) chemistry in a lab.

H: I did the opposite of you.  I started out with the chemistry degree, and then I went very liberal arts.

C: Okay.  

H: So that's unusual.  Now I've seen it happen.  What was your liberal arts degree?

C: I actually studied religion so um, a big change.  

H: Yeah, and then you got--so you just like one day stumbled into a laboratory.

C: Well, I wanted to maybe pursue a PA career and in the process took a lot of chemistry.

H: What's a PA?  

C: Oh, Physician Assistant.

H: And so now you're a grad student at UM.

C: Yep.

H: Cool.  So you, you're now doing some pretty cool research, I feel like I'm gonna say--tell me about that and then we're gonna talk about it for like, 30 minutes.  So if you're not ready for that, get ready for it.  I find this fascinating.  So give me a really, like, really brief overview.

C: So um, we're the first to use halogen bonding, which we'll talk about more in detail, to kind enforce the self-assembly of three molecular strands around iodine.  That's pretty much in a nutshell.

H: So the molecular strands then self-assemble around the iodine ions?

C: Yes.  The ions, yeah.

H: Into--

C: A triple helix, yeah.

H: And triple helixes have been created before.

C: Yeah, plenty of times in various ways, yeah.  Just not with anions.  Only one example before this, so it's kind of a hard thing to do.  

 (02:00) to (04:00)

H: So you build multiple of these strands, you stick them in a solution with iodine anions and they just assemble into these triple helixes?

C: Exactly.

H: Cool.  And that is the goal of the research is to create these triple helixes.  The process of doing it, like, how do you even know that you're on the right track when you're doing this?

C: You--when we're designing the actual strand?

H: Yeah, yeah.

C: Well that starts off actually just by thinking, like, what can I design and then you get a piece of paper, start drawing, literally, and then you take that to computer modeling so you can see it in 3D space, it's a really easy way to manipulate it, and then you get to work, actually start making the thing.  

H: So there's a lot of, I assume, like, good old fashioned organic chemistry synthesis involved?

C: Yeah, there's tons of that.  Took me quite a long time to make this thing.

H: So you--this is your project, all on you.

C: Yeah, and I thought it up, and I mean, of course there's a lot of collaboration, but yeah, it kinda just came to me one day and just pursued it.

H: Ah, that's cool.  That's cool.  So h--can you tell me how many steps are involved?

C: Last time I counted, I think it was 12-14, I wanna say, so each one requires setting up a reaction, running a purification, and then doing it all over again, so I think from start to finish it could take, I mean, if you were just working on that part, it would take probably 2 weeks to make.

H: So these I assume are carbon chains of some kind?

C: Yeah, (?~3:37) rings, and some of them are electron deficient, which gives--

H: It's unstable?

C: Well, it just kinda juices up the halogen so it can--

H: Right.  So, you talk about halogen bonding here.  I assume that there's some kind of, you know, you want the halogen bonds in a specific place in the molecule so that you'll be having them interact with the--with what?

C: Iodine, in this case.  

H: Yeah, okay, yeah.

C: And that's right, and that's what the designing is for.

 (04:00) to (06:00)

H: So are the halogens going to have a more positive charge?

C: Yeah, partial positive, absolutely.  I mean, actually, the strand itself has three positive charges that spread out, it's all conjugated.

H: Oh, okay.

C: So it's very similar to hydrogen bonding.

H: So you have a carbon halogen bond.

C: Yeah.

H: And but the halogen is super electron negative, so it's pulling, wait, no.
C: Electron positive.  

H: Electron positive.  So it's pulling, so, like--the carbon is pulling the electrons away?

C: Yeah, and the carbon is attached to some sort of group that's doing that pulling.

H: Oh, okay.

C: So it creates a electron positive region on the halogen that can then form nonconvalent interactions, just weak interactions, with anions or other species.

H: So the iodide anione needs to be in the solution before it--to do this thing?

C: Yeah.  

H: Um, like, did the iodide sort of create a complex when it like, stays in place?

C: Um, yeah, I mean, you never--in reality, it's probably a quick--

H: In and out.

C: Yeah, jumping in and out, but if you look at it over time, it's gonna spend a lot more time connected to that halogen so um, and that's what the bond is, so.

H: So you say that this idea came to you.

C: Mhmm.

H: What were you--what was your, like, thinking?  What was the goal?

C: Yeah, so I actually wanted to make a different version of this molecule, and I tried to make it and it kind of came to a cul de sac, so this was kind of a plan B and so that's what the inspiration was, like, oh, I could make a strand instead, and that's what I did, so.

H: So as a chemist, like, when you're sitting down and thinking about this stuff, what makes a molecule, makes an idea seem exciting, like something that you wanna go after and spend, you know, more than two weeks developing a 14 step process to develop it?

C: I think you always want to bring something to the table.  You don't want to make a molecule that's derivative or copying someone else, and you're standing on other peoples' shoulders so it's a really collaborative process.

 (06:00) to (08:00)

The halogen bonding community is very supportive.  It's people all over the world, and um, and so it's kind of a fun, collaborative exciting process where you, think, well, what else--what can I do that's new and how can this maybe eventually lead to an application?  So those are kind of the motivations behind it.

H: Cool.  Do you uh, have any potential applications in mind?

C: Yeah, so I mean, there are a lot, I mean, any time you can make, kind of well-defined large shape, it can have a lot of applications, but one specific one is, you know, all of our cells have these membranes, and they kinda rely ono large proteins to channel ions in and out, and those processes go wrong, you can end up with a disease like cystic fibrosis, so organic chemists are trying to design synthetic channels or carriers to serve as treatments for this, but kind of like the bottleneck right now is making huge structures, in this case large tubular structures that go into the membrane and do this transport of ions, that can be really hard synthetically, but the idea you can make one long strand, which is comparatively simple, it's 2-Dimensional, then--let self-assembly do the rest of the work, then you're a lot closer to that goal, so that's one possible application.

H: Absolutely, cool.  I was once upon a time a chemist, and I was, you know, maybe--I was a younger man.  One of the most exciting things for me was always knowing which was the most dangerous thing I was messing with when I was doing (?~7:39) chemistry, so what is the most dangerous thing involved in this particular--?

C: Um, so put a charge on these strands, we use something called (?~7:48) and it's not like (?~7:51) or anything, but basically, if you spill it on your hand or were to eat it, which--

H: Don't do that.

C: --you never do--

H: You're not doing a lot of pipetting by mouth, I hope?

C: (?~8:03)  So basically, if you were to ingest it somehow or get it on your hand, it could potentially methylate your DNA, which could lead to cancer, so it's dangerous.

 (08:00) to (10:00)

H: But you're not regularly afraid for your life?

C: Uhh...

H: I feel like chemists have a slightly shorter than average lifespan.  Not to scare you.

C: Yeah, um, I'm not too scared.  I'm not as cavalier as some of my labmates, like, my co-author, Nick, is just fearless, and he's just, I don't care.  And then I'll always say, well, we should be careful, and he always just responds like, you're gonna die of something someday.  I don't quite get the logic of that, but anyway.

H: Yeah, I don't--fearless in the chemistry lab don't necessarily mix particularly well.

C: Yeah, for sure, for sure.

H: There was a spot in my lab when I was in school and it was just blood on the ceiling, and we'd be like, how'd it get up there?  How'd it get up there though?  Like,  I understand, but up there?  Anyway.

C: Did you have any theories?

H: No, I did found out one day.  A vacuum dessecator exploded.

C: Oh, okay.  Wow, really?

H: Or imploded.

C: Imploded.

H: Hit somebody hard enough that it like, hit like an actual artery--

C: Wow, that's pretty scary.

H: Yeah, but that was years before I came in, they just didn't ever clean the ceiling.  Cool, so can we check a paper if we're interested in your chemistry?

C: Yeah, absolutely.

H: Yeah, we'll just put a link in the description.  

C: So if you wanna read it, it's kind of a lot of jargon, but you get through that and it's--

H: Does it outline the whole synthesis process?

C: Yes, it does.

H: Great.  Well, now it is time for, if you're interested, to be visited by an animal of some kind.

C: Sure.

H: A non-human animal and I don't know what it's gonna be, but let's say hello to it.

C: Cool.

J: (?~9:55) are we?

H: Oh my goodness.  

J: How are your ears?

H: Uh, this is a long distance communication strategy.

 (10:00) to (12:00)

J: Yeah, that's one of them.  I think this is just excitement.

H: Okay.

J: Yeah.  

H: Not even trying to make that noise.

J: This is just normal.  This is j--I mean, he does a quieter chatter, but this is just really normal.

H: Okay.

J: Yeah, yeah, he can scream and do the little alarm calls, which are much louder than that.

H: Okay.  

J: This is a Jenday parakeet.

H: Okay.  Whoa.  

J: Also known as a Jenday Conure.

H: Yeah, I would have said that was a conure.

J: Yeah, so conures are parakeets.

H: Oh.  What do I know?

J: What would you have called this bird?

C: A kind of parakeet probably.

J: Yeah, a lot of people think, like, oh, colorful, it's a parrot.

H: Yeah.

J: So then, it looks like a--it has a long tail, it's gonna be a parakeet, and then if that parakeet originates in South America, then it's a conure.

H: Oh.

J: Yeah.  (?~10:50)  What do you think?  You're so bright and pretty.  Do you wanna hang out with Hank?

H: Really?  Are you gonna--oh yeah, you're perfectly happy.

J: Yeah, he's a good boy, as long as you give him treats.

H: Okay.  Man, my left hand?  What am I supposed to do?  Oh, you're just--what do I do?

J: I know, you can do that.  You can do that.

H: Oh yeah, you're so gentle.

J: He's a good boy.  

H: Yeah.  'Cause it looks a little like your mouth could tear a man apart.

J: Maybe not a, like--

H: No, but like, I wouldn't want that on my finger.

J: Yeah, yeah, it could hurt.  He could break the skin.  He can't break a bone, um, there are bigger larger birds that can.

H: Yeah.

J: Like a parrot or a macaw could definitely break your bones, but yeah, not that strong, but these guys are actually one of the loudest in the Psittacine family, which is the parrot family, and they, yeah (?~11:47)

H: Yeah.  This is a good bird.  What does he like?

J: What does he like?  

H: Yeah, besides seeds.

J: Like, besides seeds? Um--

H: Like, cuddling or back scratching?

J: You know, his favorite thing in the world--you want some more?  Or do you want to try one?

C: I would love to try.

J: Oh yeah, very exciting.  

 (12:00) to (14:00)

J: Are you left or right handed?

C: Uh, right.  

J: You're right handed?  So put the treats in your right hand, unlike I did for poor Hank who had to go backwards.  Stretch one big finger out.  There you go. 

C: Cool.

J: Yeah.  

C: This is awesome.  

J: So his favorite thing besides seeds is probably his best friend.  His, I mean, not really mate, because it's a male, too, but like, they're gonna be bonded like mates, yeah.  So these guys are really social in the wild, and his best friend is actually a different species of conure, it's a half-moon conure, but they bound just as well.  Just, like, I mean, there's inter-species bonding between (?~12:44) humans too.  

H: Sure, that's great.  So it's got just a really big friend.

J: He does.  

H: That's nice.

J: Well, a little bit smaller than him.

H: Well, that's good, too, 'cause maybe you don't need to spend so much socializing time, because--

J: Exactly, yeah!

H: He's got a best friend.

J: And if they get out of, like, if they're a little bit further away, they'll both like, lean towards each and be like, I wanna by you!  And then if they, like get out of sight, then they'll contact calling back and forth. Here,  (?~13:10)  Hi.  You're a good boy.

H: Ex-pet, I imagine?

J: Yes.  Yep.  Bought actually locally at a PetSmart and um, two things happened, well, he was loud.  

H: Yeah.

J: These guys are super--they're like, one of the loudest--they are the loudest conures, I mean, (?~13:30) are the loudest.  Also, the dander from his feathers, new growth, they have like, um a sheath over their feathers and then they groom it off and it turns into dust and their dog was allergic to it.

H: Their dog was allergic to their bird.

J: This poor little dog.  So I was trying to help them with their dog, too, and I finally realized that they just couldn't live in the same house, and so we took Ecuador in and um, yeah, he's been living with us since, and hi buddy.  You did good.  You bonded right to Loulou.  So he knows one, we've been working on one, we call behaviors, some people call 'em tricks, I call them behaviors.

 (14:00) to (16:00)

We've been working on one and we'll see--you wanna try?  Ready?  One, two,--one, two, three, bang!

C: Wow.

H: Heeeyyy.

(?~14:27) Yeah, you can do a round of applause, buddy.  You did pretty good, huh?  

H: That was awesome.  Great.  And now he's gonna hang here and have his seed.  I don't mind being upside down.  I'm a bird.

J: Yum.  No, he does it all, I mean, these guys are awesome, they have these cool didodactylus feet, two toes on the front, two toes on the back so they can just flip on over.  Like going down there?  Yeah.

H: Oh, look how--

J: Nice work.  

H: Oh, look at that red belly.

J: Isn't that pretty?

H: Yeah.  

J: Yeah.  Do you want to try and get him to tip upside down on your finger?  It's pretty fun.  There you go.  Now put your thumb over one of his toes.  Yep.  

H: Oh, I didn't like that idea.  It's like, don't touch me.  Don't touch, no, don't  He doesn't trust me the way he trusts you.

J: No.  Sorry, buddy.  Do you wanna try?  

C: I don't know how, that's too advanced.

J: It is, actually, it takes--am I being too loud? I know, I know.   That was a bit of an alarm call, 'cause I was getting loud and he was like, I need to be loud too.  

H: Hm.  Must be loud together.

J: It's actually interesting because--too advanced.  It's easier for me to do it, but it takes--we have interns that come in and teach them how to handle the birds and it's one the--it is a little bit more of an advanced move.

C: Yeah.

J: Yeah.

H: To hold the bird in place.

J: To hold them up, get them to tip upside down in a comfortable way forward and then also backwards.  

H: Wow, look at that.  

J: Yeah.

H: You're like a bird juggler.

J: All over the place.  Good job.  Yeah, yeah.  These guys can live to be like, 30 years, and people buy them as pets all the time.

 (16:00) to (18:00)

J: I mean, they're gorgeous, they um, and people see them in the pet store window and they usually give them as babies, but they have, they have a baby look.  They have like these big pupils and the cute little face, and they come up and they're like, what's that?  And they play with people through the glass or bars, and then they get 'em home and they hit like, two years old.

H: Screaming all the time.

J: They mature, and they're like, give me attention, you didn't get a second one, you know, you're my mate and you need to stay with me all the time.

H: Right.

J: If you're not, I'm gonna scream because I want you to.  Yeah.

H: Yeah.  And then that's a 30 year old bird, that's hard.

J: They have up to 30 years, and they're pretty darn intelligent.  They can--who do you see?--they can learn you know, basic things like dogs can, except they're just, they're more intelligent than dogs.  They're like a one year old human, one to two year old human, but for 30 years.

H: Yeah.  Who wants a two year old for 30 years?

J: No.  A year is long enough.

H: Even if it's very pretty.  Even if it's very pretty.

J: Super pretty.  Who's that?

H: And doesn't eat very much.  

J: Ohh, thank you.  

H: Just you missed.

J: You missed everything.  Oh, no, there it is.  Ooh nice.  

H: That's good, that's not on the carpet.  

J: Nicely done.  What do you see (?~17:29)

H: Yep, that's the only--

J: That's  what he wants.

H: That's the only choice.  Thanks for visiting. 

J: Yeah.

H: You're the best.  Can you come say hi to me? 

J: Yeah.  (?~17:42)

H: Oh.  I know, I know, I'm a stranger.  But thank you for visiting us here on the SciShow Talk Show.  Thank you guys for coming on.  If you want to see more of what Jessi's up to, you can go to her YouTube channel at, and it was a pleasure to have you guys.

J: Yeah.

H: Thank you so much for coming on.

C: Thank you.

 (18:00) to (18:20)

H: And thank you for watching.  If you want to see more of this kind of thing, I know you do, you can go to and subscribe.