Ive came up with a pretty good analogy for this process 1) Think of myosin head as the firing arm of a catapult: this is when myosin head is sitting in the actin filament 2) Then, put the ammo in the catapult, which weighs the firing arm down a bit: The ammo being the ATP, which changes the SHAPE of the myosin 3)Next, cock the catapult,similar to loading a slingshot takes ENERGY: This is when ATP hydrolyzes to ADP+ENERGY (again changes shape) 4)Fire the catapult:Release the Phosphate group
You guys need to relax. This isn't an easy subject to begin with and Sal did an awesome job at explaining this. If this whole myosin and actin thing is confusing you, watch his next video about tropomyosin and troponin and it'll make much more sense.
This is one of my favourite topics of A level biology as you are looking at a fundamental level and it explains how ATP is actually used rather than just learning how it's made (Respiration).
I don't know if you're an actual college professor or not, but you should be. As everyone has been saying, you have taught me more in about an hour of watching your videos than I have learned in hours of lecture and hours of studying.
Remember this is muscle contraction, flexing your bicep for example. Think of it when your at full flex of your bicep, myosin is near (but not touching) the end. then when your release your flex, myosin returns to its initial position
wonderful reactions: adenosine triphospate to bind with adenosine diphospate plus phosphate group to cock with the high energy to produce the actin was the best reaction the myosin when bonded.👬👥👊😂
This was so helpful to watch. I didn't really understand much about actin and myosin when my biology professor lectured in class, but this was so helpful. I have learned so much.
I wouldn't understand anything of what my Bio Professor is trying to "teach me" without your help in this video - definitely sharing this with all the classmates I have so that we actually UNDERSTAND for once. Thanks so much!!
thank you so much for all the help......I didn't know where to start and where to finish up until last night I watch the entire video on membrane transport...thank you thank you. your a great teacher!!
Is there anything that you have yet to master Sal? All kidding aside, your videos are absolutely wonderful, and very helpful. Thank you so much. -A Molecular Biology College Freshman.
Well done Khan!...LOVE the way you teach this. I appreciate you writing out EVERY letter...this shows me step by step what you're thinking and doing. I learn best this way. Keep doing it this way- Don't change a thing- everyone else loves it.
Was shown this in class today :D Nice video. (Unfortunaly, none of the smaller sketches could be seen from far away XD) I think it would be even better if you could show some animations. It's a bit hard to imagine the process with still pictures.
r u a bio professor? my teacher has been trying to teach us for weeks what you taught me in 9 mins....idk if u r awesum or if she is just bad at teaching, but yeah! I LOVE your vids they r sooooooooo much clearer!!!
Awesome video. Just a quick question. What happens when the muscle "relaxes"? This lecture explains beautifully how the myosin "pulls" the actin filament, but I think after step 4 something should happen to bring back the myosin head to the initial position. Let me rephrase it. I think if the cycle ends in step 4, the muscle will be in a state of "Perma contraction". Am I right? Sorry for bad english, I am no native speaker and started to approach the subject just recently. Thanks a lot ;)
Glad I knew the mechanics before watching this. You know exactly what you’re talking about, but the way you portrayed it has deff evolved through the years. The drawing and clutter was a bit distracting here
really good explanation but im just bad at science & i still sort of don't get it =\ but i understand all of your math videos so still thumbs up to you sir ! :3
He said depending on how we view it, its either actin pulled by myosin or myosin "walking" along the actin. he also said there are thousands of myosins "walking" on every actin filament. if the myosinsare are not synchronized, that means some of them at any given time will be constraining either actin from sliding along the myosin filament or vice-versa. its like when you trying to pull something when somebody is holding it. if you guys know what's going on, can you explain?
+mohammed shatwan, he specifically mentioned that if they were all synchronized they would all detach from actin at the same time and the actin filament would move back. it's like a stretched spring.
@CherryPi420 #1--the guy has almost 2,000 videos a free information so maybe he doesn't have time to script everything perfectly #2--people need time to absorb ideas, process them and put them in our memory. If everything was written out this video would be like 2 minutes and you'd have to watch it like 10 times to absorb it.
Why does the myosin release the actin when the ATP binds to it? I study physics, and this is on my biophysics course, Im worried its for a biological or chemical reason that I have missed
Sal, I always think your right, and i think your right right now. But, my Anatomy and Physiology textbook sites that ADP and Pi are released simultaneously.
Please help cure Dystonia. Maybe were not producing something so our synaps are not fireing. So much info and no one can figure it out. Maybe its caused by a bacteria no one can detect.. and I found out nerve 4 in the brain can't be seen.. it seems so simple. All it takes is to get them foreign again. And when you have a focal dystonia a few years later another shows up. Help!
I still don't understant how chemical force is transformed into mechanical force to drive the heads to walk specifically. Could anyone explain step by step please? For example,a car engine is that piston pushed by fuel explosion push the crank to produce torque or a jet engine is that fuel mixed with pressed air is burnt to jet to produce backward force.
![BLACK BAG - Official Trailer [HD] - Only in Theaters March 14](http://i.ytimg.com/vi/Du0Xp8WX_7I/mqdefault.jpg)
Ive came up with a pretty good analogy for this process
1) Think of myosin head as the firing arm of a catapult: this is when myosin head is sitting in the actin filament
2) Then, put the ammo in the catapult, which weighs the firing arm down a bit: The ammo being the ATP, which changes the SHAPE of the myosin
3)Next, cock the catapult,similar to loading a slingshot takes ENERGY: This is when ATP hydrolyzes to ADP+ENERGY (again changes shape)
4)Fire the catapult:Release the Phosphate group
You guys need to relax. This isn't an easy subject to begin with and Sal did an awesome job at explaining this. If this whole myosin and actin thing is confusing you, watch his next video about tropomyosin and troponin and it'll make much more sense.
Thank you Khan Academy, for without you, I would not pass Nursing school.
Stephanie Clarke THIS
I am at nursing school right now and khan academy is more helpful to me than my teachers at school
This is one of my favourite topics of A level biology as you are looking at a fundamental level and it explains how ATP is actually used rather than just learning how it's made (Respiration).
Wow, I wish I had just watched this video instead of going to class today.
Wow you made this comment 8 years ago
I was in class 6 then
Boi do I have news for you
I don't know if you're an actual college professor or not, but you should be. As everyone has been saying, you have taught me more in about an hour of watching your videos than I have learned in hours of lecture and hours of studying.
Remember this is muscle contraction, flexing your bicep for example. Think of it when your at full flex of your bicep, myosin is near (but not touching) the end. then when your release your flex, myosin returns to its initial position
Perfect as always! Thanks indeed! BTW I really think your beautiful voice sounds like the voice of Anthony Bourdain!
The hardest part about anatomy is visualizing organic processes in a different orientation than what you learned it in
You have no idea how much this helped me with a biology assignment. thank you
wonderful reactions:
adenosine triphospate to bind with adenosine diphospate plus phosphate group to cock with the high energy to produce the actin was the best reaction the myosin when bonded.👬👥👊😂
This was so helpful to watch. I didn't really understand much about actin and myosin when my biology professor lectured in class, but this was so helpful. I have learned so much.
Very helpful helped me to clearly see what we have been talking about in class, thank you sal
I wouldn't understand anything of what my Bio Professor is trying to "teach me" without your help in this video - definitely sharing this with all the classmates I have so that we actually UNDERSTAND for once. Thanks so much!!
thank you so much for all the help......I didn't know where to start and where to finish up until last night I watch the entire video on membrane transport...thank you thank you. your a great teacher!!
Lots of love for khan academy
Is there anything that you have yet to master Sal? All kidding aside, your videos are absolutely wonderful, and very helpful. Thank you so much.
-A Molecular Biology College Freshman.
These videos are so incredibly helpful. I can understand stuff here immediately. Keep up the good work.
Well done Khan!...LOVE the way you teach this. I appreciate you writing out EVERY letter...this shows me step by step what you're thinking and doing. I learn best this way. Keep doing it this way- Don't change a thing- everyone else loves it.
Thank u so much......it was of great help.....
These videos are helping me pass biology :D thank you!
Was shown this in class today :D Nice video. (Unfortunaly, none of the smaller sketches could be seen from far away XD)
I think it would be even better if you could show some animations. It's a bit hard to imagine the process with still pictures.
Cheers Khan, I find the muscle physiology section of my sports science degree a lot easier now.
thanks bro I have a huge biology test tomorrow and this helped so much. But you should also talk about calcium's role in muscle contraction too.
These videos are very much helpful for me to crack NEET🙏🙏👌👌👌😁😁😁😁😁👍👍
Very good video Sal. Thank you
r u a bio professor? my teacher has been trying to teach us for weeks what you taught me in 9 mins....idk if u r awesum or if she is just bad at teaching, but yeah! I LOVE your vids they r sooooooooo much clearer!!!
Thank you! I actually get this now.
You saved my life, again. Thanks !
totally understand, very enjoy for your explaining ,thank u so much
Really nice presentation :D! helped me with my report your awesome man thanks!
Salll yay i havent heard one of your own lessons in soo long
I can see clearly now. Thank you sir.
I was on the Khan Academy website but i just had to copy url to come here and give it a like.
Good explanation sir. You're definitely the best professor or even better than a school dean. 😂👥
Brilliant videos!
hell yea bro!!Totally understood! thanks!
I love Sal Khan.
awesome video!!! really good for reviewing before test! :) Thanks!
fantastic! can't wait until the next video comes out!
Finally..! a nice simplification of the cross bridge cycle!
wonderful work!!
Awesome video. Just a quick question. What happens when the muscle "relaxes"? This lecture explains beautifully how the myosin "pulls" the actin filament, but I think after step 4 something should happen to bring back the myosin head to the initial position.
Let me rephrase it. I think if the cycle ends in step 4, the muscle will be in a state of "Perma contraction". Am I right?
Sorry for bad english, I am no native speaker and started to approach the subject just recently. Thanks a lot ;)
Yeah, I am having the same question. Maybe it just slides back, given that there is tension in the muscle
well, apparently he explains in the next video :D
step 4 ADP released is also called the power stroke.
Glad I knew the mechanics before watching this. You know exactly what you’re talking about, but the way you portrayed it has deff evolved through the years. The drawing and clutter was a bit distracting here
Phillip Dalessio from STCC brought me here, and I'm glad he did.
11 years ago this came i was in middle school
Now im in 1st year of med school watching this
last years ap essay question was on something like this. Muscle contraction. Actually how atp is used throughout the body. well awesome vid.
you just saved my chances of passing my exams!! thanks
Khan academy, keeping county jail inmates entertained on their tablets since 2014
Love how you simplify the topic my putting into simple steps.
Awesome!
I still have a question though... What happens when the myosin has crawled to the tip of the actin? :/
Thank you for any help! :)
You're intelligent
Thank you so much. Your videos are so extremely helpful.
Thank you!!!
really good explanation but im just bad at science & i still sort of don't get it =\ but i understand all of your math videos so still thumbs up to you sir ! :3
if u were ma lecturer for each course i'm doing i'm sure i'd graduate wit first honors!!!!
He said depending on how we view it, its either actin pulled by myosin or myosin "walking" along the actin. he also said there are thousands of myosins "walking" on every actin filament. if the myosinsare are not synchronized, that means some of them at any given time will be constraining either actin from sliding along the myosin filament or vice-versa. its like when you trying to pull something when somebody is holding it. if you guys know what's going on, can you explain?
+Vitaly Ievlev they are synchronised
+mohammed shatwan, he specifically mentioned that if they were all synchronized they would all detach from actin at the same time and the actin filament would move back. it's like a stretched spring.
Thank you sir
(please clear my doubt)
Where does the myosin head get the ATP molecule from?
Thank you very much SAL for this awesome video
@CherryPi420
#1--the guy has almost 2,000 videos a free information so maybe he doesn't have time to script everything perfectly
#2--people need time to absorb ideas, process them and put them in our memory. If everything was written out this video would be like 2 minutes and you'd have to watch it like 10 times to absorb it.
Delia Malone true
Outdone yourself
you're amazing !
but how myosin goes to the first place at actin molecule? because is one way movement, and myosin will get to the end of actin with a few reaction
Cool!!!!!!
I'M very weak in physiology sir give me idea that what should I do
How to download these informative videos???
Why does the myosin release the actin when the ATP binds to it? I study physics, and this is on my biophysics course, Im worried its for a biological or chemical reason that I have missed
Sal, I always think your right, and i think your right right now. But, my Anatomy and Physiology textbook sites that ADP and Pi are released simultaneously.
I agree
The AAMC is getting more than enough money to be able to sponsor a basic animation for this. Idk why we dealing with two google search images...
hello all please could anyone tell me what program is he using making this explaining video ?
+Hatem Kaabi
Khan Academy
jackie xiong thnx alot
Could a bacteria stop one of these functions?
Nikkel Farm yes
He do be actin kinda sus tho.
Please help cure Dystonia. Maybe were not producing something so our synaps are not fireing. So much info and no one can figure it out. Maybe its caused by a bacteria no one can detect.. and I found out nerve 4 in the brain can't be seen.. it seems so simple. All it takes is to get them foreign again. And when you have a focal dystonia a few years later another shows up. Help!
You mean chemical energy to mechanical work.
Intertwound?
@passikg his other videos cover that
Myosin helps free testosterone?
+Gabriel Torres testosterone has nothing to do with it
STANDARD
I still don't understant how chemical force is transformed into mechanical force to drive the heads to walk specifically. Could anyone explain step by step please? For example,a car engine is that piston pushed by fuel explosion push the crank to produce torque or a jet engine is that fuel mixed with pressed air is burnt to jet to produce backward force.
kind of confusing.
soo slooow
lol
I usually watch the KA videos at 1.5x. So what if it's slow? the content is the important part
imagine if they invested like $100 on a better mic
@ankit383 grow up >.
I get bored because he repeats :(
you are mumbling
Messy and unclear
Not good at all.
not the best video
Great video!
kind of confusing