PhET/C3/Membrane-Channels/English

Visual Cue	Narration
Slide Number 1 Title Slide	Welcome to this spoken tutorial on Membrane Channels PhET simulation.
Slide Number 2 Learning Objectives	In this tutorial we will, Demonstrate Membrane Channels, PhET simulation.
Slide Number 3 System Requirement	Here I am using Ubuntu Linux OS version 14.04 Java version 1.7.0 Firefox Web Browser version 53.02.2
Slide Number 4 Pre-requisites	To follow this tutorial, learner should be familiar with topics in high school biology.
Slide Number 5 Learning Goals	Using Membrane Channels simulation, we will learn To predict movement of particles through the membrane Types of channels present on the membrane To predict the rate of diffusion based on the number and type of channels present
Slide Number 6 About Membrane Channels	About Membrane Channels Membrane channels are proteins. They allow passive transport of solute across a membrane. The solute moves by simple diffusion through the membrane.
Slide Number 7 About Membrane Channels	Solute moves from the region of higher concentration to the region of lower concentration. The diffusion continues until the two compartments have equal concentrations.
Slide Number 8 Types of membrane channels Leakage channels: always open Gated channels: open in response to some stimulus	Two types of channels are found in membranes, Leakage channels and Gated channels. Leakage channels are always open. Gated channels open in response to some stimulus.
Slide Number 9 Link for PhET simulation	Use the given link to download the simulation. http://phet.colorado.edu
Point to the file in Downloads folder.	I have already downloaded Membrane Channels simulation to my Downloads folder.
Press ctrl+Alt+T keys. At the prompt type, cd Downloads >> press Enter.	To run the simulation, open the terminal. At the prompt type, cd space Downloads and press Enter.
Type, java -jar membrane-channels_en.jar >> press Enter. Point to the simulation.	Then type, java space hyphen jar space membrane hyphen channels_en.jar and press Enter. Membrane Channels simulation opens.
Cursor on the interface.	This is the interface of Membrane Channels simulation.
Point to the compartments and membrane.	The simulation window has two compartments separated by a membrane.
Point to solute pump. Point to solute particles. Point to green circles and blue diamonds.	Each compartment has a solute pump. Each pump has two different types of solute particles. Particles are represented as green circles and blue diamonds.
Point to green circle in the upper compartment. Point to blue diamond in the lower compartment.	By default green circle is selected in the upper compartment. Blue diamond is selected in the lower compartment.
Click on the green radio button.	We can select the particle by clicking on the radio button next to the particle.
Click on red button.	Click on the red button, to release a single particle into the compartment.
Point to the channels. Click >> drop green leakage and gated channel.	Two different kinds of channels are provided at the bottom, Leakage channels and Gated channels. Drag and drop to add channels on the membrane.
Click on the black arrow on the right-panel.	Gated channels can be opened and closed using the buttons on the right-pannel.
Point to the Play/Pause buttons. Point to Step Button. Point to the Sim Speed slider.	Use the Play/Pause button to start and pause the simulation. Step Button is activated when Play/Pause button is on Play mode. There is a slider to change the Sim speed from Slow to Fast.
Point to Show Concentrations check-box. Click on the Show Concentrations check-box. Point to bar graphs on screen.	There is a check-box on the right panel to show the concentrations of particles. Click on the Show Concentrations check-box. Bar graphs showing concentrations for each compartment appear on the screen.
Click on Clear Particles button.	Click on Clear Particles button, to clear the particles present in the compartment.
Click on Reset All button. Point to a message appears on the screen. Click on Yes button.	To reset the simulation, click on Reset All button. A message appears to prompt you to confirm the reset all settings. Click on Yes button.
Click on Play button.	Click on Play button to play the simulation.
Click on the radio button next to blue diamond. Click on red button of the pump 10 times.	In the lower compartment, select blue particle. Click on the red button to add blue particles to the compartment. Click the red button 10 times to add 10 blue particles to the compartment.
Drag >> drop 2 blue leakage channels on the membrane. Point to blue particles in upper compartment. Point to blue particles in upper compartment.	Place 2 blue leakage channels on the membrane. The blue particles pass through the channel to the upper compartment. Wait for a few seconds. Note the number of blue particles in the upper compartment.
Cursor on the particles. Point to the particles in both the compartments. Click on Pause button.	The particles move in both directions through the channels. The diffusion of the particles continues. After sometime the particles in both the compartments are almost equal. Click on Pause button to pause the simulation.
Click Show Concentrations check-box. Point to the bar graph. Click on Play button.	Click on Show Concentrations check-box. Concentrations of particles in each compartment is represented as a bar graph. Click on Play button to play the simulation.
Drag >> place one green leakage channel on the membrane. Point to blue particles and green channel.	Place one green Leakage Channel on the membrane. Observe that blue particles do not pass through the green channel.
Click on the radio button next to green particle. Click the red button 10 times.	Now add 10 green particles to the lower compartment. Click on the radio button next to the green particle. Click the red button 10 times to add 10 green particles.
Point to the channels and particles. Point to green channel.	Observe the movement of the particles. Notice that the green particles do not pass through the blue channels. They pass through the green channel only. This shows that, the channels are selective. They only allow a particular particle to pass through them.
Cursor on the simulation. Click on Pause button.	After sometime equilibrium is reached. Click on Pause button to pause the simulation. Note that at this point concentration of the particles in both the compartments are almost same.
Click on Play button.	Click on Play button. The particles continue to move in both the directions to maintain the equilibrium.
Click on Reset All button. Click on Yes button.	Click on Reset All button. Click Yes to confirm the reset all settings.
Select green particles >> Click on the red button 20 times.	Add 20 green particles to the upper compartment by clicking 20 times.
Click on blue particles radio button.	In the lower compartment, select blue particles radio button.
Click on the red button 20 times.	Add 20 blue particles to the lower compartment.
Drag >> place one blue and green gated channel on the membrane.	Place one each blue and green gated channel on the membrane.
Click on blue Open button on the right panel. Point to the blue channel on the membrane. Point to the blue particles.	Click on blue Open button on the right panel. On the membrane, blue channel opens. Blue particles move through the Gated channel in both the directions.
Click on Show Concentrations check-box.	Click on Show Concentrations check-box. Wait until equilibrium is reached.
Point to the green particles in the compartment. Point to upper compartment. Point to lower compartment.	Green particles do not pass through the Blue gated channel, hence remain in the upper compartment. Observe that there are no green particles in the lower compartment.
Click on the green Open button on the right panel. Point to the green channel on the membrane. Point to green particles in the lower compartment .	Now click on the green Open button on the right panel. On the membrane, green channel opens. Green particles pass through the green gated channel to the lower compartment.
Point to the bar graph.	Equilibrium is reached after a few minutes.
Click on green Close button on the right-panel.	Next, click on green Close button to close the green gated channel.
Point to the particles. Point to the blue particles. Point to the green particles.	Observe the movement of particles. Notice that now only blue particles move between the compartments. Green particles do not cross the compartments, as they cannot pass through blue channel.
Cursor on the interface.	This is how solute or ions diffuse through the membrane in real cells.
Slide Number 10 Summary	Lets Summarize, In this tutorial we have learnt, how to use Membrane Channels, PhET Simulation.
Slide Number 11 Summary	We have also learnt, To predict movement of particles through the membrane Types of channels present on the membrane To predict the rate of diffusion based on the number and type of channels present
Slide Number 12 Assignment	As an assignment Fill the upper and lower compartments with equal number of blue and green particles. Add gated channels of both colors on the membrane. Note if the diffusion rate increases with increase in number of channels. Give Explanation.
Slide Number 13 About Spoken Tutorial project	The video at the following link summarizes the Spoken Tutorial project. Please download and watch it.
Slide Number 14 Spoken Tutorial workshops	The Spoken Tutorial Project team: conducts workshops using spoken tutorials and gives certificates on passing online tests. For more details, please write to us.
Slide Number 15 Forum for specific questions: Do you have questions in THIS Spoken Tutorial? Please visit this site Choose the minute and second where you have the question Explain your question briefly Someone from our team will answer them	Please post your timed queries on this forum.
Slide Number 16 Acknowledgements	This project is partially funded by Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching.
Slide number 17 Acknowledgement	The Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India. More information on this Mission is available at this link.
	This tutorial is contributed by Snehalatha Kaliappan and Meenal Ghoderao from IIT Bombay. Thank you for joining.

Contributors and Content Editors

Meenalghoderao, Snehalathak