DNA replication - 3D

This 3D animation shows you how DNA is copied in a cell. It shows how both strands of the DNA helix are unzipped and copied to produce two identical DNA molecules.

To download the subtitles (.srt) for this video, please use the following link:

---
Animated by Polymime Animation Company Ltd.

[megaandry]

Learning about replication without actually seeing it makes actually no sense. A must watch for anyone studying biology-related sciences. <3

[livingmybetsylife]

Here is a basic & simplified version of the video:

BASICS:
Adenine --> Thymine
Cytosine --> Guanine

PREPARING TO REPLICATE:
-Helicase splits the DNA for replication
-Primase adds RNA bases (primer) to the leading strand.
-Why does DNA polymerase require a primer before it adds DNA nucleotides? It is because the RNA primer will have a free -OH group at the end that it can nucleotides to!
-DNA Polymerase binds to the primer to start replication!

REPLICATION:
-The leading strand TEMPLATE will have a daughter strand that is created 5' to 3', in the direction of the REPLICATION FORK (where DNA becomes uncoiled).
-The lagging strand TEMPLATE will have a daughter strand that is ALSO created in the 5' to 3' direction, but it will replicate in the OPPOSITE direction of the REPLICATION FORK.
-That's not okay! Because it is in the opposite direction of the replication fork, it needs to be made in fragments (Okazaki Fragments).

FINISHING TOUCHES:
-Exonuclease removes the RNA primers that were added to the start. We don't want RNA in our DNA!
-DNA polymerase then adds DNA bases to the missing spots where the RNA primers were.
-Ligase makes sure all the fragments are sealed

CLOSING:
-DNA is described as semi-conservative because there is one old and one new strand of DNA in each DNA.

Thanks and hopefully this will help you for your bio test
I know it did for me :)

[abduallahghanem]

Almost 8 years ago and this is one of the best DNA replication videos I've ever seen so far! Great visualization!

[ffinformer]

Step 1: Helicase
Function: Helicase is the initial enzyme in DNA replication. Its primary function is to unwind the DNA
double helix. It accomplishes this by breaking the hydrogen bonds between the complementary base
pairs, such as A-T and G-C. By doing so, helicase separates the two DNA strands, creating what is called
a "replication fork." This single-stranded DNA region is where the actual replication process will take
place.
Step 2: Primase
Function: Primase follows helicase. Its role is to synthesize RNA primers. Primase adds short RNA
sequences, known as primers, to the DNA template strands. These primers are essential because DNA
Polymerase, the enzyme responsible for adding new DNA nucleotides during replication, can only
extend an existing strand. On the leading strand, primase synthesizes a single RNA primer at the 5'
end, providing a starting point for DNA Polymerase.
Step 3: DNA Polymerase III
Function: DNA Polymerase III is the primary enzyme responsible for DNA synthesis during replication.
It adds nucleotides to the growing DNA strand. On the leading strand, DNA Polymerase III synthesizesthe new DNA strand in a continuous manner by extending from the 5' to 3' direction, using the parental
DNA strand as a template. This strand doesn't encounter the same challenges as the lagging strand,
which requires a more intricate process.
Step 4: Exonuclease
Function: Exonucleases come into play after DNA Polymerase III. Their function is to remove RNA
primers from the DNA template. Once the RNA primers are synthesized by primase, exonucleases
degrade them, creating gaps in the DNA strands. On the lagging strand, multiple RNA primers are
synthesized at different points along the template to provide starting points for DNA Polymerase.
Step 5: DNA Polymerase I
Function: DNA Polymerase I is an enzyme responsible for gap-filling. After the removal of RNA primers
by exonucleases, DNA Polymerase I replaces the RNA nucleotides with DNA nucleotides. On the lagging
strand, DNA Polymerase I works in a discontinuous manner, filling in the gaps created by the removal
of RNA primers and synthesizing short DNA fragments called Okazaki fragments.
Step 6: Ligase
Function: Ligase is the final enzyme involved in DNA replication. Its function is to seal the nicks or gaps
in the DNA backbone. It does so by catalyzing the formation of phosphodiester bonds between
adjacent nucleotides. On the lagging strand, ligase joins the Okazaki fragments together, ensuring the
integrity and continuity of the newly synthesized DNA strand.
In conclusion, DNA replication involves two strands: the leading strand, which is synthesized
continuously, and the lagging strand, which is synthesized discontinuously in Okazaki fragments.
Different enzymes work together to ensure the accurate replication of both strands, preserving genetic
information during cell division and ensuring the inheritance of genetic traits.

[melaniesantiago]

As a senior bio major I shed a tear watching this... so beautiful

[davis]

Take notes, biology teachers. This is how you teach this.

[yashsingh]

This is actually one of the best animations I've ever watched. Super clearly explained in under 4 minutes. Fantastic!

[jamirahman]

That's a gem.
Three & half a minute is more precious than three & half an hour without seeing the animation.

[zannat]

My biology teacher explained really good and now seeing this video makes dna replication totally clear to me. Thank you!

[lenad.]

Τhis was actually the only video that made me finally understand it..good job :)

[wanirayees]

I'd lost all the hope that I'd ever understand replication, after watching this precise, short and easy-understanding video, I'm feeling refreshing now. Hats off to that person who made this...

[dipteeshukla]

im literally crying because this is so good. merely reading the process just screwed me. thank you so much for the efforts.

[chirayatabasu]

A 3.30 min video made me understand what 3 lectures of 2 hrs each couldn't !

[estrellaswarez]

I’m French and I’ve understood it better in English because professors or unable to EXPLAIN IT CLEARLY IN A SIMPLE WAY !

[geetikasaini]

I learnt DNA replication from ritu man seriously telling mam ki lecture ki baad animation ki jarurat nhi hote h pr m ne yeh dekha or bhi clear ho gaya❤️🔥why not school teacher teach like this ??? Fir bol te h bache nhi pdh te

[booplesnoot]

This video is super good in helping visualize the entire replication process. Although I think there was slight oversight in the direction of the DNA strand because in the beginning of the vid, the top strand was labeled 5' on the left side and 3' on the right side, but when DNA polymerase was introduced, the top strand was suddenly 3' on the left side and 5' on the right side.

[riemomar]

This video is amazingly incredible. It is precise, up to the point and explains everything in 3:28 min with clear voice with synchronized animation. This video is the best that explains Dna replication on YouTube. It probably deserves a million likes

[TheGuitarpro]

Only video that's straight to the point and explicitly states all the steps .. THANK YOU!

[Ridha_sh]

حيا الله طلاب السادس العلمي بويه

Final year high school students in Iraq welcome you 🥲🇮🇶

[clarapalomodiaz]

this just brings me back to life and makes me forget every "imperfection" I think I have