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Mechanism of Timing and Control

Added Apr 22, 2016 •

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hi sister Anderson welcome to biology Essentials video number 25 hynynen control I'm going to talk about timing and control in plants and animals and even in bacteria by talking about something Lakeview if you ever travel and that is called a jet lag and the reasons that like nasty is that you get used to a specific time you said it was called circadian rhythm according to the amount of light that you get with the time of the day and when you fly somewhere else like this is across International everything is kind of out of whack and take your body up a little while to accommodate for that but we can because you can set up a new circadian rhythm podcast I'm going to talk about physiological events and that's going to be events that occur within a specific organism that allow us to do time or control and so and two big things you should understand about plans are phototropism that's how we grow towards or away from light and then photoperiodism how to plant respond to changing amounts of light throughout the season going to talk about the animals in the importance of circadian rhythms but we also find circadian rhythms in a fungus or in a plant as well they're all tied to the time of the day and then finally I'm going to talk about timing in and controlling bacteria and they use something called Quorum sensing a poem is we have a group of people together to vote bacterial figuring out can talk I can communicate between bacteria the same species and even between interspecies and and pretty crazy tennis awesome so I'm with the start by talking about phototropism phototropism is going to be grow towards light be called that pawsitive phototropism set the plant where to grow you can see it like over here it's going towards it and not only as the stem Grand growing toward this you can see that all the leave oriented so they can pick up the amount amount of light I'm negative phototropism would be growing in the other direction and so immediately when you plant a seed the roots are going to show negative for the compass and they're actually going to go down into the dirt or away from that and then we have gravitropism as well gravitropism in beer the gravity plant do that how does it doesn't a muscle doesn't have nerve how do they grow towards lights for has a grill away from the light well they use a plant hormone called oxen to do that this is option is a series of plant hormones that hormones are hormones in general this are chemicals that move around in and have a specific of fat into Austin what often does is it causes cells to lengthen what it really does is loosens up the cell wall and cell when you loosen up the cell wall the cell wall as water flows into the plant that actually makes it larger I'm looking for example that I put the light for the sun over on this side  end represents of the plant dramatic but let's say this is the stem of a plant that can be this time of this point right here okay I put the sun over on the side like it it's nice it looks a little happier for the sun is over here what oxen does is oxen will move inside the plant possible always move away from the light and positive phototropism but it's going to move away from the writing this correction now what is that due to the cells causes the cells to get larger than to let me turn clear this out of the way so what happens to the cells of the oxen will the cells are the auctioneers are going to get longer and it's kind of a any fun tonight as long these ones are going to change it all I couldn't quite get the animation right but what is that really going to do well instead of making it just holler on that side since all so they're connected it's going to cause this them to actually grow towards the light on another with some seeds are all attached here the whole Singh is going to move in this direction and it's going to move towards the Sun and so you could see that vampire to clear this all off and look they have put the phone on the other side song is over on this side now the auction would move in this direction and then the Stanley going to stand up like that it's plants to do is it's a physiologic respond to changes in the amount of light and I can go towards or away from the lights and they do that using oxen  photoperiodism has photo in well that means light but what they're sensing is the amount of light throughout the day the time in a dream again and weed plants you something the phytochrome phytochrome is going to be a protein that I'm inside plan and when it absorbs light it will change of confirmation in other words Sally has this red phytochrome confirmations but when it absorbs light it'll switch to a far red phytochrome so it's actually going to change it and by the amount of phytochromes that have changed their shape they can tell what time of the day it is now why would you want to know what time of the day it is or how much a light there is in a day well that tells you what season it is and that's super important I'll talk more about that in the next podcast it determines if you survive or not I'm going to do if you can classify plants and find the Day flower the length of the day and more importantly is actually the length of the night and so poinsettias will actually flower around Christmas Mayflower when the days are really really short for the nights are really really long and they're fencing that using these cytochrome or Arab DOCSIS is a is a is a lot of the time in studies in biology it's actually going to require a long day lettuce is an example of a certain the really long days are really short night flower or a dandelion doesn't care dandelions I can apply at all the time but independent of the amount of lights that they give the disallowed plants that kind of on to their physiologically respond to their environments plants move their leaves during the day and that's called a circadian rhythm but we have a circadian rhythm as well letter words that as long as the light is out our light is going to go through the eye and we're going to send that in something called the pineal gland at the small gland inside brain looks like a Pinecone but what it's going to do this going to release a chemical in your brain called melatonin melatonin is going to set our clock where are internal clock and so if you look through this is a guy this from Wikipedia pretty cool I'm so in the morning  will have a high blood the sharp rise in blood pressure rate before we getting out we stop making melatonin in the morning bowel movements or wake me at 8:30 in the morning is pretty funny that's coordination is looks like about 2:30 in the afternoon start making melatonin at night what does it mean we are set on a 24-hour schedule until our body according to the amount of light sets itself on the schedule and so that's why jet lag is a problem with you move some we're already on a different schedule until now we have to wake up at this time or have to wake up at that time so it's hard for us to do that doesn't take it for a few days and you can find us a new a new circadian rhythm the first time I read about Quorum sensing in bacteria it's freaking me out what it really is is a way that bacteria can communicate with other members of their species reasons and was of another species into a quorum is a group of in getting together and talk and communicate and something were going to give off with a cold Auto and deuces in other words protein that essentially just say I'm here and if you are one bacteria by itself a lot of those are just going to kind of go unanswered however if there are more bacteria and they give out their autoinducer the chances that one of those will bouncing to a another bacteria is going to be much greater and if we even have more bacteria there's more autoinducer than to have any have more bacteria going to even so what does that mean that you can see how crowded it is and if they're all by themselves they're going to have one behavior and if they're not they're going different radius of the really complex where the bacteria can actually communicate until what they can do they can start giving off  other proteins four different picks up the side of inducer 2km crowded it can send other proteins out that that are going to trigger a specific response so what am I buy a trigger specific respond well for example it could allow them to communicate and work together to solve could increase their virulence in other words bacteria might grow to the point where there's so many of them now it's time to actually attack where they could form biofilm are they can move really really quickly and so all Quorum sensing is a way to communicate that. About Siri to say hey this is how crowded it is different behaviors depending on that so did the real complex behaviors that we that we never even Xavier years ago and so that's how animals and bacteria respond to the timing and and they can sense their environment and I hope

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Mechanism of Timing and Control

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