Fungi - 2

by Jason Amores Sumpter
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now, fungi. Morphology is going to be a little strange. Let's say, compared to what we've seen thus far, fungal bodies are mostly made of what are called Haifa. These long filaments that are actually, um, made up of one or sometimes many, many cells and are surrounded by a kind of tube shaped cell wall that will enclose all of them in a filament, you can see a microscopic image of Haifa here. Um, there these Phil mentis strands, you see, and we can see a non artist rendition of a Haifa here. Um, each of these blocks actually represent individual cells and essentially, um, they While the cells are, uh, technically independent, they do have pores between each other and, um, these blockages or these divides in the cells, I should say they're not actually blockages. They allow passage between the cells. These divides are called SEPTA. So here this is a septum. That's gonna be the singular form of the word. And it's worth noting that, um, these fungal cells right, these Haifa have a kindness cell wall which is actually a modified beta glucose polymer. You might remember that beta glucose is what is used to make cellulose. Interestingly enough here, however, the sub units have been modified with and amino acid like group and essentially, uh, it this'll polymer. Um X is a tough sell wall for the fungal cells, and it's actually also present in insects shells, interestingly enough, And that's why when bugs die, their shells hang around and don't decompose or anything. Because, uh, there's really not a lot that digest kite. It's a very tough, resilient material. That's why you know, you can keep, for example, an insect shell from a dead insect from, you know, really, really, really long time ago, and also why fungi tend to be or tend to have these resilient, hardy cell walls. Now Haifa refers Teoh, a Nen vivid jewel filament, and we use the term Hi Fay Thio. Refer Thio Multiple Haifa. So that's the plural form. The entirety of a fun guys fungus is Hi hi fi Hi Fay are called the Mycelium, so that's essentially the the mass of the fungus, which is made up of all these interwoven haIf A that is called Mycelium. So you might hear those terms used interchangeably from time to time. But just know that mycelium is that the totality of the Haifa Haifa of Ah, Phangnga the totality of the haIf a of a fungus say that five times now, fun guy actually perform what's called extra cellular digestion. And essentially, what they do is they release enzymes and absorb the nutrients that get are The enzymes will break down compounds releasing nutrients, and these nutrients get absorbed through thief fungal. Hi, Fay. Now it's worth noting that might sound really strange, but humans technically also perform extra cellular digestion, Right? We put food into our gastrointestinal tract, and we release enzymes from cells around the G I tract that break down our food. And then those cells absorb the nutrients as the food gets broken down. The difference, really is that, um we're doing this inside of our bodies, whereas fun guy, uh, don't always, uh, funk. I don't usually do it like that. They will actually, uh, x or secrete these enzymes to the environment, break down the stuff and then absorb it. So, uh, not as weird as it sounds, but still different than the way humans do it. Now, some parasitic fungi actually have these. A special hi Fay called Historia and again singular here is gonna be a story. Um, all these Latin words I know, Um, so ah ah, story. Um, that's gonna be the singular form. And you can see them here. These air all plant cells and these dark bits that you see inserted into the plant cells. Those are the historia, and you can tell because the fungus has been stained this darker stain. So this band, you see, that's the fungus. And these nubs, it's inserting into the plant cells, those air, the storia. And this is what parasitic plants air gonna dio uh, some parasitic. I'm sorry, some parasitic fungi you're going to do to extract nutrients from plant cells. Now, with that in mind, fungi actually generally are really helpful to plants. Okay, so sometimes their parasitic always some bad apples in the bunch, right. But, uh, fungi are actually essential thio many, many land plants. And they actually formed this symbiotic association of haIf A and roots of vascular plants. Obviously, because vascular plants are the only plants that have roots and a supposed to resides might recall from plants. Now, this association of roots and fungi can be seen here in white. That is the fungal body and the little brown bits are roots. Basically, what you're looking at is, um, someone kind of like pulled a plant, flipped it upside down and brushed some of the dirt off the roots. And that's that's what we're looking at here. Now there are actually two ways that these micro Resi can form and notice that term. Micro resi right riz I that's referring Thio roots Maiko is referring thio fun guy. So we have fungal roots. Basically now, as I said, they're essentially two different versions of my core. Is I the Actually, it gets a little more complicated. You know, Azaz, I hope you realize by now we have to simplify things a little bit just to make it manageable, to talk about and to paint some broad strokes pictures. But essentially you can have Acto Acto Micro is I which, uh, form on the outside of plant cells the extra cellular surface. Um, they don't penetrate into plant cells, and you can see an example of this right here we have the artist's rendition in purple thes purple stringy bits. Those are the fun guy, and you can see that While they don't actually penetrate the plant cells, they will penetrate into the root of the plant and grow around the cells. And here you can see a new image on image of the Ecto Mike. Or is I around a route? So we're all this stringy stuff. Is the fungal body forming around the route? But it can also go the other way. Our bus killer fungi, which are sometimes referred to as Endo Micro Rizal, right endo, meaning internal. So our bus secular fungi will actually penetrate into the cells in the roots of plants. Um, however, in both instances, this is a beneficial relationship to the plants, just two different strategies. So the, uh, the main relationship here is that the fungi helped the plants get certain nutrients and help them obtain water. And in return, the fungi are provided with nutrients by the plants. So with that, let's conclude this video and I'll see you guys next time