wow, I didn't even attend this in class and I understood it perfectly, I don't even need to read the book.Sal, thanks for getting me through bio. I love you
You're great! I had an Plant physiology exam recently, where one of the questions was to explain the differences between C-3 and C-4 photosynthesis. Fortunately I watched you videos before, cause I knew everything - I wrote down everything you told and even made the same sketches you made in these videos:D I did it great, I received an A!;) So thank you very much for making videos like these and making every topic so interesting and understandable!;)
Spatial Separation from O2: In C4 Plants, CO2 fixation to PEP Carboxylase occurs in a different cell, the Mesophyll Cell. The Calvin Cycle occurs in the Bundle Sheath Cells. Temporal Separation from O2: In CAM Plants, CO2 fixation to organic acids occurs at night. During the day, with stomata closed, the Calvin Cycle occurs in the same cell with the CO2 released from the organic acids.
YOU ARE THE MAN!! So easy to understand compare to the textbook. Anyone who's taking biology and watching all your videos should be getting at least a "B". Hands down the BEST biology teacher right here!! If I had professors like you in engineering. I would be getting "A's" in most of my courses. Thank you for the videos!!
THANKS !!!! That's wonderfull. I'm a french student and i used to understand nothing to vegtal physiollogy, but thanks to you, now I do ! ;) A lot of blessing to you !
So essentially this is the way for the pep to "filter out" the oxygen and move ONLY the CO2 to the bundle sheath cells where it can be fixed by Rubisco in an oxygen-free environment
I think it should be added that the reason we want separation for the CO2 from the O2 for C4 plants, is that Rubisco will preferentially bind to O2 in as temperature increases. And C4 plants tend to be in warmer climates than C3 plants.
ALL hail King Sal..you have helped me understand the most difficult parts of my biology lessons I salute you sir and I am humbled to know , that each of your lessons are free, thank you.!!
Been watching all these videos for cell resp to now, absolutely amazing! Going into my U1 bio midterm 2 confident! Big help, even for intro university courses. Some not quite in depth required for those, but all very close and very good info! Thanks!!
this is amazing!!! and thank you soooooooooooooooooooooooooooooooooooo much. i could understand everything very clearly and beautifully about c4 photosynthesis, thanks againg. please do more and more vedeos like this. this is excellent' i'm a sri lankan student
@bbkanga00531 step 4: 1 G3P will be taken out and will be known as PGAL (3 carbon) remaining 5x 3-carboned G3P = 15 carbons step 5: 5 x 3 carbon G3P + 3ATPs ----> 3 x 5-carbon RuBP (total of 15 carbon -- and what we started with) Hope this makes sense
thanks, that helped a lot, just one thing...in the beginning of the video, when you showed the photorespiration process, shouldn't you get 3 molecules of 3-phosphoglycerate and 3 molecules of phosphoglycolate from 3 molecules of RuBP?
That is correct, Pyruvate does indeed become Acetyl-Coa before being utilized in the Citric acid cycle... which is in cellular respiration, not photosynthesis. I am a 3rd year Biochemistry student, and still get them confused. You'll get it :)
dulu ada budak cakap, cikgu dia macam sampah, sekarang lepas tengok video ini, aku berani cakap cikgu aku lori sampah ! tahniah kepada khan academy yang mampu memberi tunjuk ajar yang sangat hebat !! i am a malaysian
The remaining mystery to me is: what is preventing the O2 produced by hydrolysis of the light reactions from diffusing toward bundle sheath cells? What is directing its flow away from bundle sheath cells, but rather towards the leaf air spaces then to the atmosphere via the stomata?
@bbkanga00531 we're not using RuBP here, it's PEP. And please don't take me wrong, but seems like you didn't understand the process that well. step 1: 3RuBP in c-3 plants x5 = 15 carbons + 3 CO2 molecules = 3 carbons total of 18 carbons step 2: make 6x 3-carbon chain PGA = 18 carbons (same as above) step 3: 6 of 3-carbon PGA + 6 ATPs + 6NADPH ---> 6 G3P (still 3-carbon in each molecule so 6x3 = 18 carbons) step 4: ...
Wow, this is so damn difficult to understand. But thank you so much, it was really helpful!!! Just like C3 and C4 photosynthesis for dummies :) Once again, thanks!!
shouldn´t it be 5 RuBP because otherwise it doesn´t make sense. because RuBP has 5 carbon atoms (in your case 3*5=15) now you produce 5x 3-phosphoglycerate (5*3 = 15) and 5x phosphoglycolate (5*2=10) that would make a total of 25 carbonatoms while you started out with 15. Correct me if i´m the one who´s wrong but i thing he need´s to start out with either 5x RuBP to produce 5x 3-phosphoglycerat and 5x phosphoglycolate or you leave the 3 RuBP and reduce the other ones to 3x.
I think i kinda missing something like in the last 2 minutes, you said that the calvin cycle can occur at bundle sheets cell but at first you told us that it only pep carboxylase enzym in bundle sheets cell? How can calvin cycle occur there?
Amazing how one teacher can effectively reach so many students. God bless Khan Academy.
Yeah totally!
Amen
At 2:23 3 rubp attach with 3 o2 to give 3 3-phosphoglycerate and 3 -phosphoglycolate
wow, I didn't even attend this in class and I understood it perfectly, I don't even need to read the book.Sal, thanks for getting me through bio. I love you
My textbook speaks martian. Thank you for actually speaking english in your videos! Thank you for actually being understandable.
You're great! I had an Plant physiology exam recently, where one of the questions was to explain the differences between C-3 and C-4 photosynthesis. Fortunately I watched you videos before, cause I knew everything - I wrote down everything you told and even made the same sketches you made in these videos:D I did it great, I received an A!;) So thank you very much for making videos like these and making every topic so interesting and understandable!;)
lol "everything we've been doing is biochemistry so its nice to see a leaf" - Sal-ism # 46. This dude slays me 3:40
Spatial Separation from O2: In C4 Plants, CO2 fixation to PEP Carboxylase occurs in a different cell, the Mesophyll Cell. The Calvin Cycle occurs in the Bundle Sheath Cells.
Temporal Separation from O2: In CAM Plants, CO2 fixation to organic acids occurs at night. During the day, with stomata closed, the Calvin Cycle occurs in the same cell with the CO2 released from the organic acids.
You are an excellent lecturer. Great explanation of complicated process. Thank you very much.
my exam is coming soon and ive no idea to express how thankful i am for this video. God bless!
*Nature bless. God does not exist...
@@filipultr4435 wow, youre an atheist. congratulations! no one asked!
YOU ARE THE MAN!! So easy to understand compare to the textbook. Anyone who's taking biology and watching all your videos should be getting at least a "B".
Hands down the BEST biology teacher right here!!
If I had professors like you in engineering. I would be getting "A's" in most of my courses.
Thank you for the videos!!
I have a presentation.. and this is a very tricky teacher, u kno, he gets questions from everything. THIS helped alot man, thnx keep it up
THANKS !!!! That's wonderfull. I'm a french student and i used to understand nothing to vegtal physiollogy, but thanks to you, now I do ! ;)
A lot of blessing to you !
Thank you so very much. The explanation is excellent. And it is amazing how you can use the computer monitor as a virtual blackboard.
So essentially this is the way for the pep to "filter out" the oxygen and move ONLY the CO2 to the bundle sheath cells where it can be fixed by Rubisco in an oxygen-free environment
Got a biology teacher who really doesnt care about our grades,this video make it really simple to understand,thanks for posting this video!
I think it should be added that the reason we want separation for the CO2 from the O2 for C4 plants, is that Rubisco will preferentially bind to O2 in as temperature increases. And C4 plants tend to be in warmer climates than C3 plants.
2:35 it should be three 3-phosphoglycerate and three phosphoglycolate, not five of each
Sean Ngui Yes
Nope
German high school student here. It is amazing how this is easier in English than in German :D
Very clear information, gets it across in an interesting way and has an awesome voice to boot. Great videos man. :)
omg it is 11years old but the use of digital board and the clear explanation can make fall in love with bio. Thank you khan academy😍 p.s.:2021
This is really helpful, Thank you!
Finally I knew why does the carbon dioxide fix into carbon dioxide again.
ALL hail King Sal..you have helped me understand the most difficult parts of my biology lessons I salute you sir and I am humbled to know , that each of your lessons are free, thank you.!!
i dont think you understand how helpful you are to me and my brain :)
khan academy is really helpful for beginners in subjects
3:27 Sal - "...Plasmodesmata... sounds like the name of a horror movie...." xD
Hahahahahahahaahahahah so u mean cell wall is a horrible thing?????
wish my lecturer was as good as you. this has really helped. thanks
you saved my life and thank you for labeling everything so i can look at it again later
Thanks alot for the explanation. Never understand what C4 was but now i got it all thx to u
I thought that C4 meant a bomb
One of the best explaination I had ever seen Till Date Hats OFF MAN it really helped me a lot
Been watching all these videos for cell resp to now, absolutely amazing! Going into my U1 bio midterm 2 confident! Big help, even for intro university courses. Some not quite in depth required for those, but all very close and very good info! Thanks!!
thank you very much, your videos helped me big time with changing boring photosynthesis in my book to enjoyable photosynthesis ^^
:)
Everything's clear in my mind now. Thank you!
Grade 12? I'm using these in college! these are awesome videos.
this is amazing!!! and thank you soooooooooooooooooooooooooooooooooooo much.
i could understand everything very clearly and beautifully about c4 photosynthesis,
thanks againg. please do more and more vedeos like this.
this is excellent'
i'm a sri lankan student
Amazing.....and thanks a lot for giving such a wonderful explanation
@bbkanga00531
step 4: 1 G3P will be taken out and will be known as PGAL (3 carbon)
remaining 5x 3-carboned G3P = 15 carbons
step 5: 5 x 3 carbon G3P + 3ATPs ----> 3 x 5-carbon RuBP (total of 15 carbon -- and what we started with)
Hope this makes sense
thanks, that helped a lot, just one thing...in the beginning of the video, when you showed the photorespiration process, shouldn't you get 3 molecules of 3-phosphoglycerate and 3 molecules of phosphoglycolate from 3 molecules of RuBP?
That is correct, Pyruvate does indeed become Acetyl-Coa before being utilized in the Citric acid cycle... which is in cellular respiration, not photosynthesis. I am a 3rd year Biochemistry student, and still get them confused. You'll get it :)
"...that doesn't hurt 'cause everything we've been doing now is biochemistry. It's nice to see leaves.."
Thank Gooooooooooood
The lesson is clear enough. Thank you.
Wow c74 literally made no sense in my textbook but you explained it so eloquently (most importantly, you explained the original problem).
Omg thank you so much for this! You are my savior XD definitely feeling more prepared for finals now
Awesome video! THis is the third video of yours that I am watching. Very well explained.
dulu ada budak cakap, cikgu dia macam sampah, sekarang lepas tengok video ini, aku berani cakap cikgu aku lori sampah ! tahniah kepada khan academy yang mampu memberi tunjuk ajar yang sangat hebat !! i am a malaysian
Thank you sooooo much you saved my life :D
God bless you
You just saved my semester, thank you!
Absolutely Brilliant! Thanks for helping me understand.
Thank you SO much for these videos!
Hi, you said in the video you were going to do a video about the anatomy of the plant in more detail, I would love to see it.
This helped me a lot. Thank you.
Life saver
superb videos thanks ,concept made very easy
The remaining mystery to me is: what is preventing the O2 produced by hydrolysis of the light reactions from diffusing toward bundle sheath cells? What is directing its flow away from bundle sheath cells, but rather towards the leaf air spaces then to the atmosphere via the stomata?
I wish I could like this video more than once!
ONLY ONE WORD--AMAZING
I really love Khan's drawing
thank you
Thank you for your superb and conceptual lecture
Baller status! Thanks Khan. Yardfrazzle must have a pretty h-core high school bio.
you are awesome. Keep doin what you're doin
10:27 the enzyme is called PEP Carboxylase right? Because he wrote PEP Carboxylate?
your videos are very helpful thank you!
This is why there is a project to put together a type of rice that uses C4 instead of C3.
RuBisCo and PEP carboxylase,are both of them present in the mesophyll cells? If yes then what determines the occurrence of c4 cycle
HOW ABOUT A VIDEO ON THE C2 OXIDATIVE PHOTOSYNTHETIC CARBON CYCLE?
Perfect! Thank you.
Congratulations, you easily beat UC Berkley's videos!
thanks for the video, it's really helpful!
explaining science doesn't get much better than this. boo ya
thanks dr. khan
During C4 Photosynthesis, what mechanism prevents O2 from entering the bundle sheath (BS) cell through the plasmodesmata?
thank you so much
Nice Video That You Share , So Very Nice Thanks You C-4 Photosynthesis: How some plants avoid photorespiration
Great videos!! Help a ton!!! Keep it up!!
Very well done! Thank you!
thanks. very nice video
this finally makes me understand ty
Thank you my life saver xx
Thanks a ton!!
AMAZING VIDEO!!!!
Super helpful man. Keep it up
Yaa its really nice!
so does the o2 just got back out of the cell since it isn't used? thanks!
God bless u sir
Love uuuu
he makes everything seem less complicated. my textbook confuses me sometimes. lol
but where does PEP come 4m? ur really awesome sir..........thank you!
Very helpful
@bbkanga00531 we're not using RuBP here, it's PEP. And please don't take me wrong, but seems like you didn't understand the process that well.
step 1: 3RuBP in c-3 plants x5 = 15 carbons
+ 3 CO2 molecules = 3 carbons
total of 18 carbons
step 2: make 6x 3-carbon chain PGA = 18 carbons (same as above)
step 3: 6 of 3-carbon PGA + 6 ATPs + 6NADPH ---> 6 G3P (still 3-carbon in each molecule so 6x3 = 18 carbons)
step 4: ...
Wow, this is so damn difficult to understand. But thank you so much, it was really helpful!!! Just like C3 and C4 photosynthesis for dummies :) Once again, thanks!!
awesome work! thank you! :)
shouldn´t it be 5 RuBP because otherwise it doesn´t make sense. because RuBP has 5 carbon atoms (in your case 3*5=15) now you produce 5x 3-phosphoglycerate (5*3 = 15) and 5x phosphoglycolate (5*2=10) that would make a total of 25 carbonatoms while you started out with 15. Correct me if i´m the one who´s wrong but i thing he need´s to start out with either 5x RuBP to produce 5x 3-phosphoglycerat and 5x phosphoglycolate or you leave the 3 RuBP and reduce the other ones to 3x.
bloody amazing!!!!!
Same here !
Excellent
Wow. Now I feel like a genius.........
Thank you, its really helpful:)
Thank you sooooooo much! Yay
Wonderful!!!!!
I think i kinda missing something like in the last 2 minutes, you said that the calvin cycle can occur at bundle sheets cell but at first you told us that it only pep carboxylase enzym in bundle sheets cell? How can calvin cycle occur there?
Dude is a beast at explaining.Makes me realize how inferior my professor is...