every time i need better understanding of a concept, I always youtube it. I seem to find your presentations over and over again and I have to say I always walk away with a much better understanding vs a text book or class lecture. Thanks!
You are the BEST! I've learned so much from you as I work toward my nursing degree. My son (10) comes home from school every day and wants to do his "work" on Kahn academy...thank you!
I honestly think you have a photographic memory or can memorize a whole ton of information and truly outwit and teacher, by far one of the best teachers. Thank you very much!!
Question about looking at bacteria under a microscope. So if your looking under a microscope and see rod bacteria in chains it could be streptobacillus. But anthrax is also a bacillus bacteria that grows in chains. I know strepobacillus is gram - and anthrax is gram + . But how could you distinguish to similar bacteria apart?
you are the best . other channels are unable to explain this all with high animations but you do it with just words and handmade drawings . salute you .
Although the famous notion that bacterial cells in the human body outnumber human cells by a factor of 10:1 has been debunked. And the concept today is that are approximately 39 trillion bacterial cells in the human microbiota as personified by a "reference" 70 kg male 170 cm tall, whereas there are 30 trillion human cells in the body. This means that although they do have the upper hand in actual numbers, it is only by 30%, and not 900%.. This video is GOLD, khan academy is one of the reason that many other sites those days are making a really admirable effort in the field of visualsing medicene and serve it to medical students and all kinds of persons that are intrested on it. So khan made a big step towards a new era and we are so thankful that people like Shall exist. GOOD JOB GUYSS!!!!
I was reading up on Eukaryotes vs Prokaryotes which brought me to your page on The Difference Between Bacteria and Viruses which gave me a link to this page and am thrilled I came. You are so interesting to listen to and your 'course' is so fascinating. I've never watched a video on viruses that was so flawlessly and easily demonstrated. Your passion shines through and makes it all the more interesting. Kudos on clarifying and illustrating a subject that can quickly get extremely intricate. Loved every minute of it! Thanks so much.
I really hate to waste food but this experiment may help you to understand germ theory. If you take piece of bread and firmly press your index finger of your unwashed hand on on corner and then a properly washed hand's index finger on the opposite corner and wait a few days, I'm certain the corner that has been touched with a unwashed hand will look, moldy and defiled (don't eat the bread, throw away promptly afterwards)
Anja Ceklic(Period 5) Bacteria Video... I liked this video and how the guy explained the different aspects of how bacteria work. I learned that in one human cell we have 20 bacteria and all the bacteria on and in us make us us. The drawing of the eukarya and bacteria helped me understand that concept better. A question I have is do we have antibiotics that target only bad bacteria and do not kill good bacteria as well?
There has never been a video by this guy that I have not learned at least one interesting thing from, even for a topic I have never ever studied before. You should be EXTREMELY proud of what you are doing for education.
Just one thing I thought should be clarified: The majority of prokaryotic organisms have cell walls. That means that both Bacteria and Archaea do *tend* have cell walls, but they're not made from cellulose (so they're not the same as the ones you'd find in eukaryotic plant cells, for example).
Like at 6:35, he tends to repeat things as he types them. I find that this subconsciously REALLY helps me to retain the information. Khan is awesome. I have downloaded all of his videos for future reference. Thanks!
One mistake Sal, bacteria is 10% of the mass if water is removed. So if you weigh 150 pounds, around 70% water, if you remove the water. You're 45 pounds of non-water, so 4.5 pounds of non-water bacteria? It's hard to determine I guess.
SHANTI - I would like to learn more about the mutations of bacteria when the genes are switching back and forth and how this works. I think that it is very interesting that for every one cell in our body we have 20 bacteria!!
Waw ! You are very fantastic, and talented. Just like that it took you two seconds to draw a really good face that it would take me for example at least ten minutes. Very good explanation thank you so much !
I only took one year of Microbiology. Then met a doctor who was a microbiologist. Anyway, they don't all have walls but the ones that DON'T have walls are in the minority while the majority do have walls. With an exception as to how bacterial cell walls differ from animal cell walls.
I don't really understand what you mean. by positive or negative do you mean Gram Positive (blue or purple) or Gram Negative (Red or pink)? I'd imagine not all cells would be able to absorb crystal violet or saffarin. This sounds like a question for my Micro prof! I do know that they all have a barrier surrounding them, though, in some capacity. How else would they keep in the cytoplasm in and all the bad stuff out?
hey i love your videos they are full of information can you talk about structures of eukaryotic and prokaryotic cells and what is the program youre using ?
I am sorry that your three schools were ineffective for you. I appreciate my education and the system that delivered it. It did not hurt that I have had a few outstanding teachers. Your mileage may vary.
Bacteria are classified into two groups, gram-positive and gram-negative, based on differences in cell wall composition detected by Gram's staining. Gram-negative bacteria are more dangerous to other life forms than gram-positive bacteria. Bacteria are extrenily adaptable with regard to their physiological adjustment to changes in the enviroments. They are the principal decomposers a of most ecosystems.
omg, how did your handwriting improve? Tablet PC? Or just prowess? By the way, is Khan academy being maintained by a group of people or is it just by you?
If the bacteria is part of normal flora and is not harmful why is it harmful when transmitted.. and is the transmitted bacteria the same as normal flora ?Can someone please explain this to me?( I’m talking about bacteria in general )
Then they must not all have cell walls b/c you can't do gram staining with SOME bacteria. It has to have a qualifying condition of being either positive or negative. I can't remember which one and I'm not a Lab Technician. I lived with a Microbiologist though. He never mentioned that they have cell walls, but that doesn't mean they don't. But all bacteria are single-celled organisms.
That's some seriously bad math at about 3:43. He weighs 150, and bacteria is 10% AFTER taking away all the water. So rather than 15lbs, it's a lot closer to 7lbs
Great video. Only updating the information on the proportion of bacterias and cells in our body. It's about the same: 30 trillion each. Source: report from Israel.
