Cell cycle control | Cells | MCAT | Khan Academy

Learn about the different "seasons" of a cell's life and how it grows with time. By Raja Narayan. Visit us (www.khanacademy...) for health and medicine content or (www.khanacademy...) for MCAT related content. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video.
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[@Chancetheflapper]

For anyone looking in the comments slightly confused like I did, this is what we learnt: G1 Phase - Cyclin D -> CDK 4 & CDK 6 G1/S Phase Boundary - Cyclin E -> CDK2 S Phase - Cyclin A -> CDK2 G2 Phase - Cyclin A -> CDK1 M Phase - Cyclin B -> CDK1 (DEAAB)

[@DevangLiya]

Can we take a moment to appreciate his handwriting?

[@mahadali619]

His hand writing looks like strands of DNA

[@nehamalik1135]

@@mahadali619 hehe 😂✌👍

[@monicareyes1785]

@@mahadali619 g

[@Layan_146]

@@mahadali619هههههههههههههههههههه

[@bobbomarley6386]

You help me out so much in medschool. Either stats, chemistry or biology- your videos are super concise and informative and I am really thankful for you!!

[@Ghar-e-Hira768]

You ri8😊

[@zhijin0201]

Isn't it supposed to be having 3 checkpoints? Great vid btw

[@mouadmaskini7702]

i was going to ask the same thing

[@hampshire2821]

Chris Jin there are many, like 12 or something. It’s subjective on whether a person includes them though. In AP, they focus on 3 though

[@Kate-hu9be]

महान व्याख्या , बहुत बहुत धन्यवादl

[@Mei-jx3mp]

Thank you so much, such a simple understandable vedio... You saved me in my genetics exam.

[@dhevansivapatham8621]

"So it's important to recognize that in order to pass these checkpoints, you need to have these cyclins present, so that they can go ahead and inhibit proteins that are blocking DNA synthesis or replication from occurring, or so they can promote the production of proteins that are needed for mitosis."

[@laurac5447]

What a simple and clear explanation! Thank you

[@ambalikaudashin2718]

Wow wonderful!

[@sweetfire08]

Hey do you know something about Pgd, methods?or just some infos about preimplantation diagnosis

[@nazdvey7933]

Thank you

[@huhu9286]

thanks a lot!!

[@crocketmeow]

I enjoyed this video, but my text says: CyclinE-CdK2 inhibits pRb by phosphorylation, not CyclinD-Cdk4. pRb is a protein that binds to E2F to inactivate it and prevent cell division. If pRb remains unphosphorylated, it will bind and inactivate E2F, inhibiting S phase of interphase. [Lehinger Biochemistry, p 470, Figure 12-46]

[@countzulu99]

On wiki it states that CDK4 "was shown to be responsible for the phosphorylation of retinoblastoma gene product (Rb). Phosphorylation of RB1 allows dissociation of the transcription factor E2F from the RB/E2F complexes and the subsequent transcription of E2F target genes which are responsible for the progression through the G1phase. Just in case was curious and needed to look it up like I did. Also I found this for CDK2: "The role of this protein in G1-S transition has been recently questioned as cells lacking Cdk2 are reported to have no problem during this transition." So now I'm still kinda confused haha. Either your textbook is wrong, wiki is wrong, or Im secretly 75 and going crazy

[@bts_ffs]

Sir u r fabulous...really....!!!

[@bts_ffs]

Seeing the topic in the book I thought it's boring....bt sir ur explanation is mind blowing and really easy to understand..... Thnku...sir

[@rapmonsternotdancemonster4195]

Very helpful.. thank u

[@lilamokraoui7545]

Great video and good explanation thank you so much

[@priye_Love]

you sound like the guy that plays the atom in dcs legend of tomorrow..............great video btw

[@eliabjoshua7919]

Great video

[@catherineguiz13]

Thank you so much! This is a very useful video!!

[@adityathakur1634]

u are awesome.

[@fameenaali3604]

Thank you so much :') ❤️

[@duaam3100]

thank you so much ^.^

[@samiii19]

You explain things very clearly!

[@AmineChM21]

Good job sir

[@dudhukumar3552]

nice

[@CHEH_tf]

video on the RCP when?

[@abc-je7pp]

For G2 are you sure its's Cyclin B and CDK1? Because in the internet I see Cyclin A and CDK1? but it was very helpful with everything else, I was just a little bit confused there.

[@helenarar]

Cyclin A is active in S-phase and Cyclin-B in important for the G2- to M-phase transition

[@anthonyfigueroaa7024]

Are you an angel???

[@ashtonmeyer1580]

I'm like "oH MY GOSH; THANK YOU!! KA never disappoints

[@henrytran38]

46 pairs implies 92 chromosomes, 23 pairs still remain 23 pairs of chromosomes, chromatids double

[@sanjaykumargoyal9506]

what is the use of cdk2-E complex

[@user-yk1bf7tq7d]

Wow!! You are amazing!!!! thanks a lot :D

[@MSidd8771]

what is CDK2 and CDK4???

[@xweto100]

Cyclin Dependant kinases 2 and 4

[@belanabdulla6368]

👏👏

[@fedexido]

Very good if you are in highschool maybe

[@alsal4163]

Your comment makes no sense

[@lukakishidoz]

Is this present in plant cell?

[@dr_aliturki]

Name of app please

[@2toys708]

where is cdk6?

[@iSpaceLightning]

What does cdk mean?

[@jamalmasri8003]

I thought Cyclin A - CDK-2 allows the cell to progress into mitotic phase?

[@m.a.shahid4927]

could you make ur writing more clear? It's useless to do a video when I have trouble reading it.

[@omairhussain9801]

If you have trouble reading it, then I suggest you get your eyes checked

[@sokras1998]

also whatever he writes he also says right before. So open your ears