Bacteria (Updated)


Captions are on! Click CC at bottom right to turn off. When I was a little kid, my parents would
let me take my favorite set of dinosaurs into the tub…probably to persuade me into taking
a bath. I remember my dinosaurs well! In fact, I used to know all of my dinosaurs. I had epic dinosaur battles. Sometimes my sister would play with them,
too…just…a little differently. Anyway, I remember that one day, unfortunately,
my favorite stegosaurus lost his head. I mean, literally, it just popped off. And while I was determined to get my parents
to fix it, we discovered that there was stuff growing in the toy. Now, I realize what was actually large enough
to be visible was likely mold, but at the time, my mother told me that Sergeant Stegosaurus
would have to retire from the bathtub, and I’d have to get a new one because bacteria
had taken over. It led to two misconceptions I developed about
bacteria: (1) that bacteria were only found on or in things that had gotten contaminated
somehow and (2) that bacteria are always bad and that is why Sergeant Stegosaurus required
replacing. Those are both not correct. First of all, there probably were bacteria
in the dinosaur along with the mold. But that shouldn’t be surprising, because
bacteria are everywhere. Bacteria are found in our houses- yes, even
very clean houses- and they are found outside. Bacteria colonize our skin and our digestive
system. That addresses the first misconception that
you only find bacteria on contaminated or “dirty” surfaces. And as for the second misconception, well,
bacteria sure do get a bad reputation. Now I’m not disagreeing that the toy should
have been thrown out. That was a good decision. There was probably mold that was in that toy
dinosaur- a fungus – but there was likely plenty of bacteria growing there with it. A growing community of mold and bacteria…not
ideal for a bath toy. But we do want to mention that many times,
all bacteria are lumped together as a bad thing- which shouldn’t happen, because not
all bacteria are bad. In fact, many types of bacteria are helpful
for organisms and ecosystems. We’ll give you some examples. Some of the bacteria that colonize your skin
are beneficial and actually help keep harmful strains and other types of pathogens from
growing. Bacteria in your digestive system actually
help break down food and some can produce certain vitamins. Some types of bacteria are used in producing
some foods that we eat. In ecosystems, bacteria have a very important
role as decomposers. Bacteria also have major roles in the nitrogen
cycle to fix nitrogen that plants need. These are just a few examples of helpful,
beneficial bacteria. Now that’s not to say bacteria can’t be
pathogens. Bacteria are the cause of strep throat, tetanus,
tooth decay, some forms of pneumonia, diphtheria, salmonella, cholera…I could go on. Antibiotics can be used to combat some of
these. And while antibiotics are very important for
destroying bacterial infections, we shouldn’t leave out saying that some broad spectrum
antibiotics can harm some of the “good” bacteria as well. Also, we should mention that antibiotics do
not work on viruses. Viruses are pathogens that are not made of
cells at all; you can check out our video on them. Additionally, there are vaccines which can
prevent many types of both bacterial and viral infections. Ok, so what are bacteria exactly? In the three domains of life, bacteria encompass
one of them. They come in different types of shapes as
you can see here. Some of them are heterotrophs—meaning they
consume or feed on some organic matter. But some are autotrophs—they can make their
own food. Plants aren’t the only one that can be autotrophs. Let’s take a look at a bacterium here—bacterium
is just singular word while bacteria is plural. A bacterium is a prokaryotic cell, which are
generally much smaller than eukaryotic cells like ours. If you recall from our prokaryotic vs. eukaryotic
cells video, that means bacteria do not have a nucleus or other membrane-bound organelles. But you will find ribosomes, cytoplasm, a
cell membrane, and nearly all bacteria have a cell wall. Like all living organisms, bacteria have DNA. Bacterial DNA, while still double stranded,
is arranged in a circular shape. Depending on the species, bacteria can also
have a flagellum to help with movement, a capsule which can help give them extra protection
or attachment abilities, or pili which can help with attaching to surfaces…including
each other. Oh, and many bacterial species have a plasmid. Which is basically like…extra DNA. More about that later. Bacteria have some intriguing abilities that
are different from our human cells that we’d like to mention. Unlike our own body cells which perform mitosis
and cytokinesis to divide, bacteria generally multiply even faster in a process called binary
fission. This is a type of asexual reproduction when
the bacteria can easily divide to make a copy of themselves. Since it is asexual reproduction, the daughter
cells would be expected to be identical to the parent cells unless there is a mutation. Some types of bacteria do have the ability
to share genetic material with each other. Remember how we mentioned that bacteria can
have a plasmid—an extra copy of DNA with usually just a few genes on it? Bacteria can share these plasmids with each
other in a process known as conjugation. The pili can be used to share this genetic
information with each other. If the plasmid happens to have a gene that
gives some degree of resistance to an antibiotic, this may allow the bacterium that received
the plasmid to survive exposure to that antibiotic. Which could be very problematic. You can learn more about how antibiotic resistance
can develop over time in bacteria in our natural selection video. Bacteria can also pick up plasmids from their
environment. Often when this happens it is during a time
of stress for the bacteria. In a process known as bacterial transformation,
scientists can use a type of stimulus—such as a heat shock—to induce bacteria in a
lab setting to pick up genetic material. There are all kinds of these uses for these
genetically engineered bacteria that you can explore. Some types of bacteria can form endospores. Endospores allow bacteria to be survivors
in all kinds of hostile environments: lack of nutrients, freezing temperatures, drought…just
some examples. This is a reason why hospitals have to be
very good at sterilization processes. We won’t go through the process of endosporulation—or
how bacteria reactivate after forming endospores—but this is definitely something interesting to
explore Finally, some types of bacteria (along with
other types of prokaryotes called Archaea), can be extremophiles. Unlike our own cells, extremophiles can live
in extreme environments where there may be excessive heat, chemicals that our cells would
find toxic, or even radiation. Overall, we share this planet with so many
kinds of bacteria that scientists continue to learn more about them every day. And if this kind of topic interests you, you
may want to look into the study of microbiology. So many careers- from agriculture to the medical
field to environmental work- rest heavily on the study of microbiology. Well, that’s it for the Amoeba Sisters,
and we remind you to stay curious.

100 Replies to “Bacteria (Updated)”

  1. How do two blue amoebas give birth to a pink and purple amoebas? I need to review punnet squares. Would the color blue be dominant or recessive? I think it would be dominate, and both parents are heterozygous that way they could both have the pink/purple gene but blue is what showed up. What do you think?

  2. This our newly updated bacteria video! Find our old one, from several years ago, here: https://youtu.be/kxM_9DL2GYw So what has changed in this updated video? Well, Petunia's art has come a long way as we continue to try to get better. And this video has additional info about endospores, conjugation, binary fission, and transformation that aren't mentioned in the old video.

  3. Cute video, buuuuuuuuuuut I'm sort of sad you didn't include transduction! 🙁 The big three!! I did like the drawings with transformation. 🙂

  4. I like u r anime and this topic is in 7 th class or standard or in some schools in India this topic is in 3rd class

  5. Jesus! I was looking for this video just today. So lucky it was released on the same day I am curious about bacteria after watching your ab,av, and vac video :).

    Thanks so much for enlightening humanity !

  6. I haven’t been to your guys’ channel in a while, it seems you’ve got a new animations style, it’s cute!

  7. I love watching your videos 💖
    I am from India and currently preparing for Medical entrance exam for college. To my surprise your videos really cleared my concept on mitosis meiosis and many more 🍻
    Thankyou for that ❤

  8. In the first ever intro class in my microbiology degree, the professor said something I'll never forget: that we often view bacteria and viruses as organisms living in OUR world, but in fact it is us eukaryotes that are living in THEIR world. PS: Love the animations, they're adorable and funny xD

  9. My science teacher Mr.Brown only plays your videos for explanations
    He also always says "we're going to watch an amoeba sisters video since we all love the amoeba sisters" just wanted to put that out there ^^

  10. Hi, just wanted to say yall help me so much and I appreciate you guys so much!!! Thank you and please don't stop what you guys are doing! Much love.

  11. Can you do the four important features of the genetic code, and just information/eplaining the genetic code in general please 💕

  12. Can you start putting 5 question quizzes on the side of the information bar to make sure we understand the topic?? 🙂

  13. maybe not all bateria are bad, but u r?!?!?!?!?!? get epically trolled boooonbs

    DONT LOOK AT )ME ._. REEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

    lol jk u njot bunny rabbit hahahahhaha

    .–.–.-.-.-.-..-.-.fortnite

  14. Actually, the symbol of medicine is the staff with only ONE snake around it, the staff with two snakes around it is the symbol of many gangs and criminals.

  15. I don’t know if you here this enough, but these videos have helped me so much throughout my freshman year, whether I watched these willingly trying to catch up on a missed class or being forced to watch them in bio. These videos have also helped me to prepare for the dreaded state exams that most kids just “half-ass”-my English teacher. These videos save me a lot of time and about 3 anxiety attacks I have from missing a lesson. So, thank you for using an entertainment platform to educate students. You saved my grade lol.

  16. My friend is germaphobic he is determent to be so clean that bacteria will die, i told him that microbes like mold, bacteria, amoeba, and others are everywhere even at the cleanest spot, he didn't believe me

  17. I just wanna say, I've been panicking all day due to my biology exam in a couple hours, the last biology one for this year, and where I really need the marks.
    Just sitting here going over notes, before I head out, and listening to you going over different subjects has actually relaxed me a ton, so cheers for that!
    Have a great day!

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