00:02
Hello my dear students, the concept given in the question is about transcription and translation process of protein synthesis in prokaryotes and eukaryotes.
00:21
Yes, what is required for us is to describe the common features either in pro or procarriots in eukaryotes or if it is found in both prokaryotes.
00:34
Carrier and e carrierots with respect to the given terms or statements in the five sub -questions.
00:40
Let us get into the explanation with respect to the specific image.
00:46
So my dear friends, in the first sub -question, they say about 70s.
00:52
70s refers to the ribosomes.
00:56
And ribosomes are of two types if you see.
00:59
As you see it in the image also, like 70s and 80s.
01:05
Are two types of ribosomes.
01:07
Now 70s type of ribosome we see it in prokaryotes.
01:12
Okay, this is in prokaryotes.
01:14
Whereas 80s ribosomes, we see it in eukaryotes.
01:19
Okay.
01:21
Now these have two such subunits.
01:24
The larger subunit of 70s is 50s and the smaller one is 30s.
01:30
Whereas if we see it in 80s, the larger one is 60s and the smaller one is now this s refers to swedborg unit which is nothing but the sedimentation coefficient at the time of centrifigation.
01:47
So when we centrifigated the specific unit or the specific you know weight of the ribosome which gets settled during centrifigation based on that only the number is been given.
02:00
Okay.
02:01
So 70s ribosome is found in prokaryotes and 80s is found in u -carriots.
02:06
Yes, this is about the first sub -question.
02:10
Now, the second sub -question talks about splicing.
02:15
Now, my dear friends, splicing actually refers to trimming or removal of non -coding sequence of mrnmn, nothing but exons.
02:30
That is nothing but exons, okay, which is a non -coding sequence of mrna.
02:39
Okay, this has to be trimmed.
02:42
And introns.
02:43
Which is the coding sequence of mrna gets ligated.
02:49
So if this is the mrna which has been formed after, you know, transcription, a portion of it is found to be exon and the other one is intron.
02:59
So this specific piece is been removed or being spliced.
03:04
The technique or that step is called as splicing.
03:07
Now this is mostly seen in eukaryotes, whereas in prokaryotes, it is extremely rare.
03:16
Because this spliceosomal pathway or that step itself is absent in the prokaryotes if you see it.
03:30
So it is very rare in prokaryotes, but it is present in dukaryotes.
03:36
Yes, understood.
03:38
So that is about the second sub -question.
03:40
Let's go to the next sub -questions.
03:43
So the next sub -question, it actually talks about polysststeronic.
03:53
Polycystronic mrna means the one which codes for multiple different proteins.
04:04
So one mrna is coding for multiple different proteins is called as polycystronic mrna which is present in prokaryotes...