Difference between revisions of "PhET/C3/Gene-Machine-The-Lac-Operon/English-timed"
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|| 00:08 | || 00:08 | ||
− | || In this tutorial we will | + | || In this tutorial, we will demonstrate '''Gene Machine - The Lac Operon, PhET simulation'''. |
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|| 00:16 | || 00:16 | ||
− | || To follow this tutorial, | + | || To follow this tutorial, learner should be familiar with topics in high-school biology. |
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|| 00:23 | || 00:23 | ||
− | || Here I am using | + | || Here I am using: |
+ | '''Ubuntu Linux OS''' version 14.04, | ||
− | Java version 1.7.0 | + | '''Java''' version 1.7.0, |
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|| 00:34 | || 00:34 | ||
− | || Firefox Web Browser version 53.02.2 | + | || '''Firefox Web Browser''' version 53.02.2. |
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|| 00:40 | || 00:40 | ||
− | || Using this simulation, students will learn about | + | || Using this simulation, students will learn about: |
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|| 00:44 | || 00:44 | ||
− | ||1.Lactose regulation | + | ||1.Lactose regulation |
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|| 00:46 | || 00:46 | ||
− | || 2.Genes involved in Lactose regulation | + | || 2. Genes involved in Lactose regulation |
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|| 00:50 | || 00:50 | ||
− | || 3.Factors affecting '''LacZ''' gene regulation. | + | || 3. Factors affecting '''LacZ''' gene regulation. |
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|| 01:17 | || 01:17 | ||
− | || '''Promoter''' | + | || '''Promoter''' initiates transcription. |
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|| 01:20 | || 01:20 | ||
− | || '''Operator''': It is a | + | || '''Operator''': It is a segment of DNA where repressor binds. |
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|| 01:31 | || 01:31 | ||
− | || The three structural genes in '''lac Operon''' are | + | || The three structural genes in '''lac Operon''' are '''lacZ''', '''lacY''', and '''lacA'''. |
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|| 01:40 | || 01:40 | ||
− | || These genes are | + | || These genes are '''transcribe'''d as a single mRNA, under control of one promoter. |
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||01:55 | ||01:55 | ||
− | || Genes of the '''Lac Operon''' can be expressed and their proteins | + | || Genes of the '''Lac Operon''' can be expressed and their proteins '''translate'''d. |
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|| 02:08 | || 02:08 | ||
− | || '''lacY''' encodes '''Beta-galactoside permease''' | + | || '''lacY''' encodes '''Beta-galactoside permease'''. It will enable transport of lactose into the cell. |
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|| 02:23 | || 02:23 | ||
− | || Use the given link to download the simulation. | + | || Use the given '''link''' to download the simulation. |
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|| 02:36 | || 02:36 | ||
− | || To run the simulation, open the terminal. | + | || To '''run''' the simulation, open the '''terminal'''. |
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|| 02:40 | || 02:40 | ||
− | || At the prompt | + | || At the prompt, type: '''cd Downloads''' and press '''Enter'''. |
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||02:47 | ||02:47 | ||
− | || Then type | + | || Then type: '''java space hyphen jar space gene hyphen machine hyphen lac hyphen operon undrenscore en dot jar''' and press '''Enter'''. |
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|| 03:04 | || 03:04 | ||
− | || '''Gene-Machine-The Lac Operon''' | + | || '''Gene-Machine-The Lac Operon''' simulation opens. |
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|| 03:09 | || 03:09 | ||
− | || The simulation screen shows 2 tabs at the top | + | || The simulation screen shows 2 tabs at the top- |
'''Lactose Regulation''' and | '''Lactose Regulation''' and | ||
− | '''Lactose Transport''' | + | '''Lactose Transport'''. |
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|| 03:56 | || 03:56 | ||
− | || At the bottom of the screen we have | + | || At the bottom of the screen, we have- a slider to set the speed of the animation, |
'''Play'''/'''Pause''', | '''Play'''/'''Pause''', | ||
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||04:28 | ||04:28 | ||
− | || Similarly drag '''lacI gene''' and place it on the '''operon'''. | + | || Similarly, drag '''lacI gene''' and place it on the '''operon'''. |
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|| 04:51 | || 04:51 | ||
− | || '''LacI''' is a '''lac''' | + | || '''LacI''' is a '''lac repressor protein'''. |
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||05:29 | ||05:29 | ||
− | || Next assemble the '''LacZ''' gene. | + | || Next, assemble the '''LacZ''' gene. |
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||05:32 | ||05:32 | ||
− | || Drag and place | + | || Drag and place |
'''Lac promoter''', | '''Lac promoter''', | ||
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||06:46 | ||06:46 | ||
− | || This '''mRNA''' is in turn | + | || This '''mRNA''' is in turn '''translate'''d to '''LacZ''' protein. |
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||07:11 | ||07:11 | ||
− | || Observe the Interior Lactose Level meter, lactose level decreases. | + | || Observe the '''Interior Lactose Level''' meter, lactose level decreases. |
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|| 08:03 | || 08:03 | ||
− | || Click on '''Auto''' radio button on the Lactose injector. | + | || Click on '''Auto''' radio button on the '''Lactose injector'''. |
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|| 08:24 | || 08:24 | ||
− | || Observe that '''LacY''' protein | + | || Observe that '''LacY''' protein binds to the '''Cell Membrane'''. |
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||08:55 | ||08:55 | ||
− | || It blocks transcription of the '''Lac operon''' | + | || It blocks transcription of the '''Lac operon''' when there is no lactose present in the cell. |
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|| 09:17 | || 09:17 | ||
− | || Let us summarize | + | || Let us summarize. |
− | In this tutorial we have demonstrated | + | In this tutorial, we have demonstrated how to use '''Gene Machine-The Lac Operon''', '''PhET simulation'''. |
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|| 09:29 | || 09:29 | ||
− | || We have also learnt about | + | || We have also learnt about: Lactose regulation, |
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||09:35 | ||09:35 | ||
− | || Genes involved in Lactose regulation | + | || Genes involved in Lactose regulation, |
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|| 09:44 | || 09:44 | ||
− | || An an assignment, | + | || An an assignment, remove some of the components of the '''Operon''' such as Operator, Promoter and Genes. |
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||09:54 | ||09:54 | ||
− | || Run the simulation. And | + | || '''Run''' the simulation. And observe the results and give explanation. |
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|| 10:01 | || 10:01 | ||
− | || The video at the following link summarizes the Spoken Tutorial project. | + | || The video at the following link summarizes the '''Spoken Tutorial''' project. |
− | + | ||
Please download and watch it. | Please download and watch it. | ||
|- | |- | ||
|| 10:10 | || 10:10 | ||
− | || The '''Spoken Tutorial Project '''team: conducts workshops using spoken tutorials and | + | || The '''Spoken Tutorial Project '''team: conducts workshops using spoken tutorials and gives certificates on passing online tests. |
− | + | ||
− | gives certificates on passing online tests. | + | |
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|| 10:39 | || 10:39 | ||
− | || Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India. | + | || Spoken Tutorial Project is funded by '''NMEICT, MHRD,''' Government of India. |
More information on this mission is available at this link. | More information on this mission is available at this link. |
Revision as of 11:41, 14 August 2018
Time | Narration |
00:01 | Welcome to this tutorial on Gene Machine - The Lac Operon simulation. |
00:08 | In this tutorial, we will demonstrate Gene Machine - The Lac Operon, PhET simulation. |
00:16 | To follow this tutorial, learner should be familiar with topics in high-school biology. |
00:23 | Here I am using:
Ubuntu Linux OS version 14.04, Java version 1.7.0, |
00:34 | Firefox Web Browser version 53.02.2. |
00:40 | Using this simulation, students will learn about: |
00:44 | 1.Lactose regulation |
00:46 | 2. Genes involved in Lactose regulation |
00:50 | 3. Factors affecting LacZ gene regulation. |
00:55 | The lac operon is a set of genes responsible for regulating lactose metabolism in E.coli bacteria. |
01:05 | An operon is made up of 3 basic DNA components: Promoter, Operator and Structural gene. |
01:17 | Promoter initiates transcription. |
01:20 | Operator: It is a segment of DNA where repressor binds. |
01:26 | Structural gene: A gene which codes for protein. |
01:31 | The three structural genes in lac Operon are lacZ, lacY, and lacA. |
01:40 | These genes are transcribed as a single mRNA, under control of one promoter. |
01:47 | Genes in the lac operon specify proteins that help the cell utilize lactose. |
01:55 | Genes of the Lac Operon can be expressed and their proteins translated. |
02:01 | The gene product of lacZ is β-galactosidase which cleaves lactose. |
02:08 | lacY encodes Beta-galactoside permease. It will enable transport of lactose into the cell. |
02:17 | lacA encodes for β-galactoside transacetylase. |
02:23 | Use the given link to download the simulation. |
02:28 | I have already downloaded Gene Machine-The Lac Operon simulation to my Downloads folder. |
02:36 | To run the simulation, open the terminal. |
02:40 | At the prompt, type: cd Downloads and press Enter. |
02:47 | Then type: java space hyphen jar space gene hyphen machine hyphen lac hyphen operon undrenscore en dot jar and press Enter. |
03:04 | Gene-Machine-The Lac Operon simulation opens. |
03:09 | The simulation screen shows 2 tabs at the top-
Lactose Regulation and Lactose Transport. |
03:19 | On the Lactose Regulation screen, You will see two floating RNA polymerase in blue colour. |
03:27 | Observe an incomplete operon which needs to be assembled. |
03:32 | Here, you need to match each part given at the bottom, to it's specific place on the gene. |
03:39 | Click on the Show Legend check box at the bottom-right corner. |
03:44 | This will turn-on the Legend panel on the right-side of the screen. |
03:49 | The Legend panel helps you to identify the molecules present on the screen. |
03:56 | At the bottom of the screen, we have- a slider to set the speed of the animation,
Play/Pause, step button and Reset All button. |
04:10 | Let us now start assembling the gene. |
04:14 | Click on lacI promoter. |
04:17 | The specific portions on the gene are highlighted in yellow color. |
04:23 | Drag lacI promoter and place it on the operon. |
04:28 | Similarly, drag lacI gene and place it on the operon. |
04:33 | The floating RNA Polymerase molecule binds briefly to the lacI promoter. |
04:39 | This will activate the lacI gene to produce mRNA. |
04:44 | This mRNA is translated to LacI protein which is seen floating on the screen. |
04:51 | LacI is a lac repressor protein. |
04:55 | It binds to the Lac operator region of the Operon. |
05:00 | In the absence of lactose, it will block the RNA polymerase to transcribe the LacZ gene. |
05:08 | Notice that as soon as LacI protein is produced, Lactose injector appears on the top-left corner of the screen. |
05:18 | Click on the Show Lactose Meter check-box at the bottom-left corner. |
05:24 | Meter will give an idea about interior lactose level. |
05:29 | Next, assemble the LacZ gene. |
05:32 | Drag and place
Lac promoter, Lac operator as prompted by the highlighted yellow portions on the operon. |
05:42 | LacI protein floating around will now bind to the operator region of operon. |
05:49 | Now place the LacZ gene on operon. |
05:53 | Since the LacI is bound to the LacZ Operator region, it blocks the RNA polymerase to produce mRNA.
Hence no LacZ enzyme is produced. |
06:06 | Pump a few molecules of lactose on to the screen using Lactose injector. |
06:13 | There are 2 options for pumping, Manual and Auto. |
06:19 | Select Manual option. |
06:22 | Press the red button on the injector. |
06:26 | Observe the Lactose level in lactose meter. |
06:30 | LacI bound to the operator, acts like Lactose sensor. |
06:35 | Lactose molecule bind to the LacI and leaves the Operator region. |
06:41 | The RNA Polymerase will now be able to transcribe the gene. |
06:46 | This mRNA is in turn translated to LacZ protein. |
06:52 | LacZ is Beta-galactosidase enzyme. |
06:56 | It cleaves lactose into glucose and galactose. |
07:01 | Lactose molecules bind to LacZ protein. |
07:05 | LacZ protein dissociates lactose molecules as shown on the screen. |
07:11 | Observe the Interior Lactose Level meter, lactose level decreases. |
07:17 | Click on Lactose Transport screen. |
07:21 | In addition to all the features of the Lactose regulation screen, Lactose Transport screen has Cell Membrane and LacY gene. |
07:31 | As demonstrated previously, assemble the Operon. |
07:36 | Drag and place all the components of the Operon in their respective places. |
07:52 | Click on Show Legend and Show Lactose Meter check box. |
07:58 | Pump-in few molecules of Lactose using Lactose injector. |
08:03 | Click on Auto radio button on the Lactose injector. |
08:08 | LacI, LacZ and LacY proteins are produced. |
08:14 | LacY is Beta-galactoside permease enzyme. |
08:19 | It enables transport of lactose into the cell. |
08:24 | Observe that LacY protein binds to the Cell Membrane. |
08:29 | Now lactose molecules permeate into cell with the help of LacY protein. |
08:36 | Inside the cell, lactose molecules are metabolized by LacZ enzyme as shown on the screen. |
08:46 | Factors affecting LacZ gene regulation- |
08:51 | The lac repressor acts as a lactose sensor. |
08:55 | It blocks transcription of the Lac operon when there is no lactose present in the cell. |
09:02 | When lactose is present, the lac repressor loses its ability to bind DNA. |
09:09 | It floats off the operator, clearing the way for RNA polymerase to transcribe the operon. |
09:17 | Let us summarize.
In this tutorial, we have demonstrated how to use Gene Machine-The Lac Operon, PhET simulation. |
09:29 | We have also learnt about: Lactose regulation, |
09:35 | Genes involved in Lactose regulation, |
09:39 | Factors affecting LacZ gene regulation. |
09:44 | An an assignment, remove some of the components of the Operon such as Operator, Promoter and Genes. |
09:54 | Run the simulation. And observe the results and give explanation. |
10:01 | The video at the following link summarizes the Spoken Tutorial project.
Please download and watch it. |
10:10 | The Spoken Tutorial Project team: conducts workshops using spoken tutorials and gives certificates on passing online tests. |
10:21 | For more details, please write to us. |
10:25 | Please post your timed queries on this forum. |
10:30 | This project is partially funded by Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching. |
10:39 | Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.
More information on this mission is available at this link. |
10:53 | This tutorial is contributed by Snehalatha Kaliappan and Meenal Ghoderao from IIT Bombay.
Thanks for joining. |