including the small and large subunits of the ribosome and finally, The process is broken into three stages: Let’s see the process in action… Eukaryotic mRNA, the substrate for translation, has a unique 3′-end called the poly-A tail. mRNA also contains codons that will encode for specific amino acids. A methylated cap is found at the 5′-end. Translation initiation begins when the small subunit of the ribosome attaches to the cap and moves to the translation initiation site. tRNA is another key molecule. It contains an anticodon that is complementary to the mRNA codon to which it binds. The first codon is typically AUG. Attached to the end of tRNA is the corresponding amino acid. Methionine corresponds to the AUG codon. The large subunit now binds to create the peptidyl (or P) site and the aminoacyl (or A) site. The first tRNA occupies the P site. The second tRNA enters the A-site and is complementary to the second codon. The methionine is transferred to the A-site amino acid, the first tRNA exits, the ribosome moves along the mRNA, and the next tRNA enters. These are the basic steps of elongation. As elongation continues, the growing peptide is continually transferred to the A-site tRNA, the ribosome moves along the mRNA, and new tRNAs enter. When a stop codon is encountered in the A-site, a release factor enters the A-site and translation is terminated. When termination is reached, the ribosome dissociates, and the newly formed protein is released.


  1. It looks so much more complicated within the textbooks, but it's far easier to see it being visualized. Thank you.

  2. The whole animation of this video is just so satisfying to watch plus the concept is explained so beautifully.. never understood this in class and now my mind is blown lol

  3. I spent an hour studying this from my book but couldn't imagine well. But damn this video explained in to me within 4mins.

  4. Clear and simple, and thanks for explaining the 5' 3' directionality! No mention of the proteins involved (such as peptidyl transferase which is what merges the amino acid of the A-site to the polypeptide of P-site), but a very nice guide to the overall process!

  5. Translation is where the mrna is translated into many identical polytide chains .it occurs in the cytoplasm(ribosomes polysomes) .then the polypeptides are liberated into the convides of the endoplasmic reticlum where they stat thier maturation.

  6. I found this video to be really very helpful.The brief and animated description made translation topic extremely easy.

  7. Overall a nicely made video. Chemically, the transfer mechanism as cartoonized here, doesn't make sense, though: the peptide chain does not dissociate from the tRNA in the P-site and then attaches to the tRNA in the A-site. It's the amino group of the amino acid in the A-site that first attacks the carbonyl group of the amino acid in the P-site, forming a covalent bond in a tetrahedral intermediate, then forming the peptide bond and simultaneous breaking of the bond to the tRNA in the P-site.

  8. Such a great video!!! Well-explained, easy to understand and all of that in 3min30! Thank you so much, very helpful!!!

  9. Thanks for shearing this video.

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  10. 2 hours read the text got nothing and understood it well in 3 mins thanks.
    to fellow studs for best result write the captions in a notebook(can be used as notes) and visualize the procedure in mind. thanks anyways

  11. But how do the tRNA molecules know that they're the correct one to go down to the mRNA next? How do they know that they have the correct Anticodon for the next mRNA Codon? Why doesn't the wrong tRNA molecule ever go down to the mRNA by mistake?

  12. 11 years old video. I was 7 years old when they uploaded it. Now here i am watching it the night before my A Level biology exam 🙂
    Wish me luck 🙂

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