WEBVTT 00:00:00.000 --> 00:00:03.020 (MUSIC) 00:00:06.520 --> 00:00:06.960 I’ll 00:00:06.960 --> 00:00:11.020 never forget a circular red spot I developed on my arm when I was in elementary 00:00:11.020 --> 00:00:12.020 school. 00:00:12.020 --> 00:00:16.491 It left a lasting memory in my mind, because it was something called ringworm and, with 00:00:16.491 --> 00:00:20.260 my active imagination, I thought I was now infected a ring-shaped worm. 00:00:20.260 --> 00:00:23.830 I learned you’ve got to be careful about names, because ringworm isn’t caused by 00:00:23.830 --> 00:00:24.840 a worm at all. 00:00:24.840 --> 00:00:29.570 It’s actually a fungus which it turns out is pretty common and can be carried by many 00:00:29.570 --> 00:00:31.900 things like pets or soil. 00:00:31.900 --> 00:00:37.230 And since up to that point, I was used to antibiotics as a way to treat infections, 00:00:37.230 --> 00:00:39.940 I assumed I’d be given antibiotics. 00:00:39.940 --> 00:00:41.260 But I wasn’t. 00:00:41.260 --> 00:00:44.829 I was given an antifungal cream instead, and it went away. 00:00:44.829 --> 00:00:49.410 So, it made me wonder – what made it different from the bacteria that had made me sick in 00:00:49.410 --> 00:00:50.540 the past? 00:00:50.540 --> 00:00:51.760 Why wasn’t I given antibiotics? 00:00:51.760 --> 00:00:55.210 Well antibiotics target bacteria. 00:00:55.210 --> 00:01:00.420 Antibiotics can destroy bacteria by affecting their ability to reproduce, damaging their 00:01:00.420 --> 00:01:05.799 cell walls, or interfering with their ability to make proteins that they need to survive. 00:01:05.799 --> 00:01:07.310 Just some examples. 00:01:07.310 --> 00:01:12.740 But it turns out bacterial cells and fungal cells are very different cell types. 00:01:12.740 --> 00:01:18.170 In fact, fungal cells have more in common with your cells- which are animal cells- than 00:01:18.170 --> 00:01:20.350 they have in common with bacterial cells. 00:01:20.350 --> 00:01:25.709 And that has a lot to do with the comparison of prokaryotic cells with eukaryotic cells 00:01:25.709 --> 00:01:27.159 which is what we will focus on. 00:01:27.159 --> 00:01:31.420 First, just a refresher---recall that the modern cell theory includes the statement 00:01:31.420 --> 00:01:35.499 that all living things are made of one or more cells. 00:01:35.499 --> 00:01:36.499 All living things. 00:01:36.499 --> 00:01:42.069 In the three domains of life, prokaryotes are organisms that can be bacteria or archaea. 00:01:42.069 --> 00:01:47.570 They are unicellular which means they are single-celled organisms. 00:01:47.570 --> 00:01:53.979 Eukaryotes are organisms that fit all in this last domain Eukarya---eukaryotes may be protists, 00:01:53.979 --> 00:01:56.429 plants, animals, or fungi. 00:01:56.429 --> 00:02:03.399 They can be unicellular or they can be multicellular, which means they can be made up of many cells. 00:02:03.399 --> 00:02:04.710 Like you! 00:02:04.710 --> 00:02:09.930 By the way, just to clarify: the word "prokaryote" is typically used to refer to the organism 00:02:09.930 --> 00:02:10.940 itself. 00:02:10.940 --> 00:02:15.320 When you are describing its cell, you are describing a prokaryotic cell. 00:02:15.320 --> 00:02:19.920 Same for eukaryote- "eukaryote" typically refers to the organism itself and when you are 00:02:19.920 --> 00:02:24.390 describing its cells, those are eukaryotic cells. 00:02:24.390 --> 00:02:28.320 Prokaryotic cells and eukaryotic cells do have a lot in common. 00:02:28.320 --> 00:02:29.330 Both have DNA. 00:02:29.330 --> 00:02:33.210 That’s critical because DNA is the cells’ genetic material. 00:02:33.210 --> 00:02:39.530 Both prokaryotic cells and eukaryotic cells have ribosomes, which are small organelles---an 00:02:39.530 --> 00:02:41.960 organelle being like a “tiny” organ. 00:02:41.960 --> 00:02:45.040 The ribosomes have the important job of making proteins. 00:02:45.040 --> 00:02:46.840 Got to make protein. 00:02:46.840 --> 00:02:50.570 Both cells have cytoplasm, the jelly fluid within cells. 00:02:50.570 --> 00:02:56.000 Both of them have a cell membrane- also known as a plasma membrane- which is critical because 00:02:56.000 --> 00:03:01.760 it controls what goes in and out of the cell and therefore maintaining homeostasis. 00:03:01.760 --> 00:03:03.650 All cells have a cell membrane. 00:03:03.650 --> 00:03:08.250 Now as for cell walls---most prokaryotic cells have cell walls. 00:03:08.250 --> 00:03:13.310 Many eukaryotic cells---plant cells and fungus cells for example—can have cell walls. 00:03:13.310 --> 00:03:18.480 But there are plenty of eukaryotic cells that don’t have cell walls such as animal cells. 00:03:18.480 --> 00:03:24.540 What makes prokaryotic cells and eukaryotic cells different is especially interesting. 00:03:24.540 --> 00:03:27.980 Eukaryotic cells are more complex than prokaryotic cells. 00:03:27.980 --> 00:03:30.690 They tend to be larger than most prokaryotic cells. 00:03:30.690 --> 00:03:34.900 And to help me remember some more differences in this next part, I like to remember that 00:03:34.900 --> 00:03:41.760 “pro” in prokaryote rhymes with “no” and “eu” in eukaryote rhymes with “do.” 00:03:41.760 --> 00:03:44.930 Prokaryotic cells have no nucleus to contain their DNA. 00:03:44.930 --> 00:03:49.850 So, you will find their DNA is not contained within a nucleus; it’s a bit messy here. 00:03:49.850 --> 00:03:53.190 They have no membrane-bound organelles. 00:03:53.190 --> 00:03:57.900 Membrane-bound organelles are fancy organelles that have their own membrane like the nucleus, 00:03:57.900 --> 00:04:02.280 mitochondria, the endoplasmic reticulum, and the Golgi apparatus. 00:04:02.280 --> 00:04:08.290 A big indicator of eukaryotic cells is this nucleus- eukaryotic cells DO have a nucleus 00:04:08.290 --> 00:04:10.370 to contain their DNA. 00:04:10.370 --> 00:04:15.681 Depending on what type of eukaryotic cell it is---it could have different types of membrane-bound 00:04:15.681 --> 00:04:16.839 organelles. 00:04:16.839 --> 00:04:22.789 For example, a plant cell is likely to have chloroplasts while an animal cell would not. 00:04:22.789 --> 00:04:25.900 Wow, look at all this alphabetized vocabulary. 00:04:25.900 --> 00:04:30.150 If you want to try to practice your skills, pause the video and see how many of these 00:04:30.150 --> 00:04:35.949 vocabulary words you can use to compare and contrast prokaryotic cells with eukaryotic 00:04:35.949 --> 00:04:36.949 cells. 00:04:36.949 --> 00:04:42.629 It’s important to grasp that all cells of living things fall in one of these two categories. 00:04:42.629 --> 00:04:47.860 And understanding the characteristics of these two cell types can help us better understand 00:04:47.860 --> 00:04:54.639 the diversity of living things whether they are archaea, bacteria, protists, fungi, plants, 00:04:54.639 --> 00:04:55.729 or animals. 00:04:55.729 --> 00:05:00.499 And in the case of my example- realizing whether an infection you’re dealing with involves 00:05:00.499 --> 00:05:07.509 prokaryotic cells (such as bacteria) or eukaryotic cells (such as the fungus). 00:05:07.509 --> 00:05:10.800 Well that’s it for the Amoeba Sisters, and we remind you to stay curious!