okay so today we are going to talk about the protests the protest material that are in this lecture are contained within chapter 28 of your textbook which is Campbell Biology 10th ediction your textbook divides this chapter into six main sections I have sort of subdivided or set off sections 2 through five because they are specifically about the wide variety of the kinds of protests whereas SE one and six apply to all protests here is a nice example of a protest this is a kind of a stentor you will be able to observe living ones of these in lab so definitely take a moment to check out the stentors oh stentors are found in most freshwater systems uh they can easily be found in puddles and we definitely have them in the ponds here on campus okay so let's talk about what protests are first off protests are are ukar that means they are in the domain ukaria which make them makes them different from bacteria and arkans bacteria and arkans are in two different domains and are made of procaryotic cells protus however are made of eukaryotic cells eukariotic cells are a bit more complex than procaryotic cells specifically because they have little subdivisions inside of them little compartments inside of them these little compartments are what we call organ ORS these organel are actually specifically designed for specific functions for example there's organel that are specific for breaking down molecules sort of digesting things there are other organal that are specific for um getting an extracting energy from food sources uh there are other organel that are good for making things that the cell needs for example maybe a hormone the cell is uh exuding keep in mind it's important to bear in mind that organism and most eukariotic lineages are protests so most ukar are protests I know the ukar you're used to seeing are plants animal and fungi those are not protests protests are any ukar that is not in Kingdom Plante kingdom Animalia or kingdom fungi the word protest means a catchall group it just means all the rest of the UK carot there are many many kingdoms of ukar within what we call the protests okay so most eukaryotic organisms are protest well it turns out most protests are single celled what that means is most ukar are single celled unbeknownst to us because these are so tiny we never actually really see them so since we have now moved from procaryotes in the last chapter to ukar and this chapter I would like to take a moment to talk about how we got eukaryotic cells um so there's a lot of evidence that suggests that UK carots originated through endosymbiosis endosopic is basically a relationship a mutualistic relationship between two species and in this case um so both species live in a close Association but endosymbiosis is when one species one organism lives in inside the other organism the other organism is what we call the host so you have a symbiant that lives inside the host often and usually endosymbiotic relationships are also mutualistic meaning that both organisms involved in the relationship benefit from the relationship okay so how on Earth did we get eukaryotic cells through endosymbiosis it turns out as far as we can tell that the original organel in UK carot specifically mitochondria and all the different kinds of plastids an example of a plastid is a chloroplast as far as we can tell those used to be independent free living procaryotes and at some point they were engulfed by the ancestors of early eukaryotic cells mitochondria was one group of procaryotes and uh mitochondria evolved by endosymbiosis of some sort of proteobacterium there are actually prot bacteria Free Living proteo bacteria in the world that very much resemble mitochondria that are in all uh eukaryotic cells plastids on the other hand evolved by a later endosymbiotic event of a photosynthetic cyano bacteria now of course you are plenty of cyano bacteria still in the world you looked at some uh this week in lab um these plastids very much resemble Free Living cyano bacteria for example there are cyanobacteria that look just like chloroplasts here's a nice sequence of diagrams attempting to demonstrate the sequence of events here okay so up in the very top left we have our ancestral procaryote and it has its DNA just kind of floating around in the cytoplasm keep in mind the DNA generally stays waded up in one little spot well over time this ancestral procaryote of course does have a number of infoldings a lot of pro carrots have that but these infoldings became so concentrated that it ended up um enucleating or surrounding the DNA this particular procaryote was heterotrophic meaning it ate other procaryotes for its f for example potentially it ate an aerobic bacterium in this particular instance for some reason the bacterium that it engulfed to eat did not get digested and that bacterium ended up Surviving and even IND independently reproducing inside of the larger procaryote what we now have now is actually a eukaryotic cell and so you can see that that bacterium over time became so endosymbiotic it actually cannot survive outside of the larger cell and as a matter of fact the larger cell relies so much on that mitochondria for cellular respiration that the larger cell cannot rely without the mitochondria in a separate endosymbiotic event we have the ma the mitochondria already in this particular cell but this particular cell had a second engulfment of a bacterium in this case a photosynthetic bacterium and at this point this ancestral photosynthetic ukar uh this ukar is so dependent both on the plastids for example maybe a chloroplast for making for capturing energy from the Sun and then the mo Andria for releasing that energy from sugar molecules that this entity exists as a singular entity so what is some evidence supporting this entire idea that UK carots evolved as a result of endosymbiosis of other procaryotes which ended up becoming some of these organel well first off the inner membranes of monoch condriac are just like the membranes of procaryotes second off these two or groups of organel the mitochondria and the plastids have their own DNA okay so for example if I were to grab one of your cells you would have your DNA in the nucleus of your cell but also all the little mitochondria in yourself would have DNA as well matter of fact they not only have their own DNA they also have their own ribosomes those little new those little mo excuse me those little mitochondria yes uh go through their own kind of transcription their own translation they go through their own um cycle of reproduction within your cells um under their own sort of schedule that has nothing to do with the schedule of your cell reproduction your mitosis of your cells um the ribosomes that are insides of those organel are also like procaryotic ribosomes oh and the DNA itself is more similar to procaryotic DNA than it is to eukaryotic DNA all of those things suggest that the mitochondria and the plastids used to be Freel living procaryotes okay well there's a lot of different kinds of protest as I've mentioned the dominant group of ukar on the Earth are what we just call the protus kind of makes sense because the word protus means a catchall group okay so protest actually exhibit more structural diversity and more functional diversity than the other three groups of UK carots that we're going to examine this semester the other three groups of ukar are the fungi the plants and the animals so protus are all the rest it's any ukar that is not in kingdom fungi Kingdom analia or Kingdom uh Plante now most protos are single celled however there are plenty of colonial protos and multicellular protos for example seaweed algae that is a kind of protus it is not a plant uh single sub protus actually can be very complex keep in mind that even if an organism is single celled it's still having to do all of the biological functions that you with your billions of cells are able to do so a single cell does the same job that your body does with its billions of cells so single cell organisms can be quite complex now protos are the most nutritionally diverse of all the ukar we have protests that are photo autotrophic uh meaning that they capture their energy from sunlight that's what the photo part of the word means and that they breathe in a little carbon dioxide for their carbon Source these photo autotrophic protus contain chloroplast and actually go through photosynthesis we also have heterotropic protus specifically chemoheterotrophic protus remember these are organisms whose mode of nutrition is to get energy from chemicals and carbon from chemicals so these organisms absorb organic molecules or ingest larger food particles we also interestingly enough have protests who are able to sort of mix it up if you will these are protest that when they are in sunlight can go through photosynthesis and when they're in the dark or where there is no sunlight they can become chemoheterotrophic and eat other things now some protus reproduce asexually Maybe by something a little bit like mitosis or a little bit like binary fusion uh while other protests reproduce sexually some protests even have meosis and gtes and fertilization so we have the entire spectrum of sexual versus asexual reproduction within the group we call protests right now as far as we can tell we can divvy up all the ukar into four main supergroups now I'd like to point out these are not kingdoms these are just large groups of organisms that as far as we can tell through DNA analyses these are slightly more Rel related to each other within each group than they are to each other between each group okay so but our understanding of the relationships between these groups does change rapidly um and this particular topic is the one that changes the most from one edition to the next edition of the textbook so if you have an older edition of the textbook this might be slightly different in your edition of the textbook we are going with what the information in addition 10 has though which is as follows these are the four main supergroups of all UK carots as discerned through DNA analysis okay so on the left hand side of the screen we actually have a single line coming up onto our screen scen and that represents the ancestor of all UK carots you can see that single line divides into four main lines which extend all the way to the center of the screen the top group are the excava the excava as you can see are all sort of highlighted yellow all three of those groups are considered procaryotes or excuse me all three of those groups are considered protests so all of the excava are protest our second group is the largest group it's the S CLA which stands for strop pales alvit and Ryans uh so that group again are all protests as well our third group are the archip plastids now the archip plastids include three main groups of protus but also the land plants are considered archo plastids so the land plants descended from an ancestral protus that is now what we consider part of the archo plastin super group our very last group are the unicons Unicon I'd like to point out that five of those are protus the uh yellow highlighted ones but two groups the fungi and the animals are their own separate kingdoms and are not considered part of the protests I'd like to also point out the DI or the images that are on the right hand side of the screen we have the excava we have an little example there there I believe that's Giardia our um s clay we've got some diatoms right there you'll be able to see diatoms in lab the um the another s Clay is at the bottom there that's a radiolarian it's another kind of s we actually are not going to be able to see those in lab the arip plasas that includes um a lot of the photosynthetic protests and that is volvox in that image right there it looks sort of like a balloon with other balloons in of it and they're usually green you'll definitely be able to see those both um in prepared slides and living specimen in lab and then finally the unicons Unicon and then that image right there is a picture of an amoeba you'll definitely be able to see living amibas and prepared slides of amibos in lab let's take a closer look at the plases as I mentioned before as far as we can tell plastids and mitochondria both origin ated as free living procaryotes that were engulfed by another kind of procaryote and they ended up existing within that proo as an endos symbiot and to where they both both of the symbiant now rely so much on each other that one cannot live without the other so mitochondria Rose first through descent from a bacterium that was engulfed by a cell from an AR um um the arkans the plasted lineage on the other hand evolved later from a photosynthetic Sun cob bacteria that was engulfed by a heterotrophic eukarion so the plasted lineage was already was engulfed by something that was already a ukar this is what's called serial endosymbiosis this is where you have a procaryote engulfed one time to make a UK carote then a UK carote engulfs another kindo procur a second time it's best to understand through this diagram so we have what's called primary endosymbiosis where we have um some sort of heterotrophic ukar that ends up Okay so we've already got our heterotrophic UK carote and this heterotropic ukar ulves a photosynthetic cyanobacterium and that cyanobacterium ends up evolving into a chloroplast what makes this primary endosymbiosis is because we have a cell that engulfs a procaryote so when the endos symbiot the one living inside is a procaryote becomes is derived from a procaryote that's what we call primary endosymbiosis it turns out primary endosymbiosis led to the diverse a wide range of diversity of different kinds of pro procaryotes including green algae including red algae what's interesting is that these algae ended up becoming engulfed themselves on several occasions during eukariotic Evolution red and green algae underwent secondary endosymbiosis in which they were in turn ingested by the heterotrophic protest so here we have our little red and green algae and they are in turn engulfed by another kind of heterotrophic UK carot this leads to secondary endosymbiosis okay so what makes it secondary endosymbiosis it is secondary endosymbiosis when the symbiot that is engulfed is a UK carote secondary endosmosis led to even further uh diversity of the protus so let me quickly review primary and secondary endosymbiosis primary endosymbiosis is when the symbiot the one that ends up inside is a procaryote secondary endosymbiosis is when the symbiant the one that ends up inside is a UK carote which implies that that little symbiant already went through primary endosymbiosis this primary and secondary endosymbiosis does help explain the huge range of diversity that we have within just the protus and keep in mind the protus are the dominant group of ukar nots on Earth so the huge variety of UK carats on Earth can be explained by primary symbiosis and then secondary endosymbiosis both primary and secondary endosymbiosis are both independent from the Sy endosymbiotic theory of how we got uh mitochondria to begin with keep in mind that's just endosymbiosis it's not necessarily primary or secondary all right let's go ahead and talk about diversity of protu what we just covered is material that applies to all the protus now let's go ahead and start looking at those four main groups of protus the first group are the excavat the excavates these include a couple of different characteristics types of protu produce with modified mitochondria and protu with a unique kind of flagella if you remember from the procaryotes chapter a fagella is basically a tail a tail that can be moved around to help Propel an organism in its environment so together though the clay excava is characterized by its cytoskeleton um it has some features that are unique to that group you don't really have to know those features it's just one it's one of the characteristics it has this Unique Kind of SK cytoskeleton some members of the excava even have uh a feeding groove on the outside of their single cell a little area a little um divot if you will on the outside of of their their membrane which they use in helping to capture food the excava as you can see have been expanded in that image I'd like to point out the other three superg groups of protus are below it the SAR clade the archip plast is and the unicons right now we've expanded just the excava to look at it more closely but the excava include three main groups keep in mind there's thousands of species Within These groups you just need to know the larger groups uh but the diploids the parabasalids and the N ugino zoans are all excavat the diplomonads and the Paras basilides both lack plastids so no chloroplast no other kinds of plast but they do have slightly modified mitochondria the dipl Lonas and the parisit are characterized by usually living in anerobic environments for example the diplomonads these guys have mondri that are greatly reduced that we call mitosomes instead these organisms derive energy from their anerobic uh environments so they go through anerobic biological Pathways biochemical Pathways anerobic remember means going through cellular respiration the absence of oxygen these also have two nuclei they have two equal siiz nuclei not sure how that works out genetically and they also have multiple flagella not just a single one a nice example of a diplon is giardia Giardia is uh the reason you don't want to just randomly drink water from streams lakes and rivers in North America this is the thing that gets that is in there that it actually can make you uh have digestive problems afterwards so it's kind of a protus and it's in most most North American Natural streams lakes and rivers and it's why you don't want to drink the water parab basilides on the other hand um also have reduced mitochondria called hydrogenosomes uh these generate some energy anerobic a nice example of a parapac silid that actually um is a problem for humans is called tronus vaginalis a tronus vaginalis is a pathogen it's a sexually transmitted disease and it can cause yeast infection looking symptoms in human females and there's a nice picture of one right there that's a single celled organism there the last group of the excava are the euglenoids the ugoo excuse me um the ugino or ukina is a really diverse clay and it includes most of the different modes of nutrition within a single clay you've got predatory heterotrofos you've got photosynthetic autot tropes You' got ones that can mix it up for example ugina can mix it up and you've even got parasites the main feature that makes all ulina together in the same group group is that they have they inside the aella they have a unique cytoskeleton feature um it's a rod and it's made of it's a crystal Rod it's it's made of specific kinds of um crystalline kind of compounds that is different from other protu there are a couple of kind of ukoo couple of main groups there's the Cano plastids and the ukids this is a picture of the cross-section of that crystallin Rod that runs inside the fagella of the ukoo so let's talk about the canop plastin this is a subgroup of the ukoo the canol plastids have a single mitochondria um and inside that mitochondria is uh the DNA is all kind of in a mass called a canop plast um the free living species of canal plastids are consumed consumers of bacteria proc carots they live in aquatic environments and some damp terrestrial environments some of them can be parasitic a couple of examples of a Cano plastids that actually affect humans uh trypanosoma and uh the tricos genus um generally causes various kinds of sleeping sickness in humans um and so uh Shaga disease is one example of a trypanosoma disease and it is a Cano plastid Shaga disease is actually transmitted by the sety fly and it is common in um tropical areas these little gray ribbon looking things are actually tripan and they actually the they're swimming amongst human red blood cells right there the little red puffy almost Duty looking things those are little innocent red blood cells and the little eel looking thing is the trypanosoma it's a sing single celled organism you'll definitely be able to see these during lab the other group of the ukoo are the ukids now the ukids have one fella maybe two fella emerges from a little pocket at the end of of the cell some species are mixotroph they can be both autotrophic for example when there's sunlight and heterotrophic when there's not sunlight I will tell you you'll have the opportunity to look at Living ukids during last today here's a nice diagram of IDs um and as you can s they see they've got their fella coming out of a little pocket at the end of the cell now you will be able to examine living ukids during lab now these ukids when you put them in with other kinds of protus they become heterotrophic they become predators and so please please be careful about not intermixing the living organisms uh Because by the end of both the labs for this week uh all the amibas will be consumed by the ukids if they get all mixed up so try to keep them apart if you will our second super group of all UK carots is the S clave socalled for strop pile alveolate and raran this second group just like the excava is solely made up of protests now the S clave is a very diverse super group but as far as we can tell they all came from the same ancestor let's start with the strop pales the strop pales are grouped together um because most of them have a hairy flagellum a hairy tail paired with a smooth flagellum so wherever you have a hairy one you also have a smooth one um it includes some of the most important photosynthetic organisms on Earth uh these make up a lot of phytol Plankton are from protest that live in this group your first type of strop pile are the datom you'll definitely be able to look at some prepared slides of datom during lab now diatoms are single cell algae I would like to point out that the word algae just means a protest that is photo autotrophic a photosynthetic protest that's what the word algae means datom are single cell algae with a unique feature uh datom have a sort of a cell wall that is made of silicone it's glasslike and so datom come in a very sort of geometrical shape to them you can see an image of a datom here on the lower right hand of the slide that is just one of the thousands of shapes these come in but they always look very geometric co uh they are a major component of phytoplankton uh why do phytoplankton matter well phytoplankton are absorbing the majority of carbon dioxide out of the atmosphere they actually do quite a bit more work than trees do um in addition they are the base of the food chain for any aquatic environment uh what's interesting is these cell walls that these diom have make it so fossilized diom are very very um they stay along for around for a long time so we find lots of fossil diatoms the second group of strumental piles are the golden algae now golden algae are named because they're golden this just means that they actually have specific um pigments in them uh so yellow and brown carotenoids another example of an organism that has uh carotenoids or things like carrots um sweet potatoes these kinds of things now the cells of golden algae are typically B flatulate um with both fala near one and I would like to point out golden algae are um mostly single celled but a lot of them are Colonial and so a lot of them live together in colonies here's a nice example of a colony of golden algae and they tend to reflect this Golden Light although they are photosynthetic for the most part some of them can be mixotrophic our third group of the strumental piles are the brown algae now brown algae tend to be the largest of the algae they are all multi-celled and most are Marine the brown algae are what you usually refer to when you're talking about seaweed and so for example the giant seaweed which you usually call kelp can live in Fairly deep parts of the ocean and extend way up into the top layers of the ocean now brown algae do have specific parts of their body just like you have arms and legs and a torso brown algae also have Parts the part part that it grabs on to the bottom of the seafloor is called the hold fast so the hold fast is almost root-like that it helps the brown algae grab onto a substrate so it anchors the algae and then it also the sort of the middle body part is the stemlike Stipe so sort of like a a trunk of a tree if you will is the stype and the leaflike blades extend off of this dip there are a lot of similarities between brown algae and plants um however ever the brown algae and plants evolve through different lineages so those similarities are not homologous they're not from ancest ancestors they are analogous they are due to similarities to similar environments here's a nice picture of a brown algae