The process by which DNA controls the production of polypeptides (1 Viewer)
- Thread starter Zeref
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Carrotsticks
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You have to understand the entire process.
Try YouTube, it really helped me learn how polypeptides are formed (especially with all the animations etc).
Try YouTube, it really helped me learn how polypeptides are formed (especially with all the animations etc).
Zeref
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Carrotsticks
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I thought so too.
Don't worry, the Search for Better Health is a really interesting topic, so that'll make up for it.
Rhinoz8142
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Definitions barely mean anything, it's the process that counts. You can be asked on the process or they might drop in a specific case scenario. Understanding the process is extremely important, and it pretty much forms the foundation.
Here's a link that can help: http://www.hartnell.edu/tutorials/biology/index.html
I haven't specifically looked into this but I think this one is for eukaryotes, not prokaryotes. Just check it.
Zeref
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celadoncity
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I know it sounds complicated when you first start it but there are SO many resources out there that explain it really well (including a 70s hippie interpretive dance: http://www.youtube.com/watch?v=u9dhO0iCLww )
Don't be put off by the terminology (at first I was like WTF is a ribosome) and if a word comes up that you don't know, look it up rather than leaving it. I don't know what kind of detail they want at the HSC level but you could have a look on Khan academy
It seriously isn't that hard. Many youtube videos will be over inclusive of information regarding translation and transcription. Perhaps try a bio textbook? You don't need to know the subunits of ribosomes, just the main players.
Transcription = information from DNA > transcribed to RNA > RNA moves out of the nucleus into the cytoplasm
Translation = information from RNA > polypeptides/proteins
This is the most basic breakdown. You will need to know more.
Transcription = information from DNA > transcribed to RNA > RNA moves out of the nucleus into the cytoplasm
Translation = information from RNA > polypeptides/proteins
This is the most basic breakdown. You will need to know more.
Maxwell
bow peasants
It is essential you know how the process of polypeptide synthesis occurs and how to model this process. I believe there is a dot point that pertains to this, asking you to develop a simple model of polypeptide synthesis (so definitions will NOT be enough). Heaps of people don't get this (people in my class cried because they didn't understand it), so don't worry, haha.
When I was explaining it to my friend (and others) I found the main difficultly encountered was comprehending the meaning of transcription and translation (I am serious).
Think of transcription as REWRITING (because it is, lol). This occurs in the NUCLEUS.
What happens here is:
1) The double stranded DNA unwinds itself, exposing a section of a gene that is to be expressed, i.e. a particular section that codes for an amino acid (which in turn makes/comprises a polypeptide)
2) RNA polymerase (an enzyme) moves along this gene (the unwound bit of the DNA), attaching loose RNA nucleotides (a phosphate, a sugar and a nitrogenous base). Remember that nitrogenous bases only pair COMPLEMENTARY - adenine with thymine and cytosine with guanine. This ensures the gene is copied EXACTLY. Note here that thymine (the nitrogenous base) is replaced with uracil (why, you ask? Because YOLO; but in all seriousness, you don't need to know why - you just need to know this happens). Uracil acts EXACTLY like thymine - that is, it will ONLY pair with adenine (this means thymine is not present when DNA is expressed - or REWRITTEN - in terms of RNA).
3) Once this gene is copied, the matured RNA moves outside of the nucleus, and makes its way to the RIBOSOME (it moves out to the cytoplasm first and makes it way to the ribosome). It is now know as MESSENGER RNA (mRNA).
Okay, now translation occurs. Think of translation, as well, translation. The overarching idea here is that the mRNA's specific sequence (from copying the base sequence of the aforementioned gene EXACTLY) here is TRANSLATED in terms of amino acid. These amino acids THEN go on to form a polypeptide (remember many amino acids can comprise a polypeptide and many polypeptide can comprise a protein - or an enzyme). Then you have a polypeptide, yay.
The process is as follows:
1) The mRNA bonds with the Ribosome because the mRNA hasn't been friend-zoned. Think as the Ribosome as an e-Kindle or whatever the fuck the digital book-readers are called.
2) The Ribosome (digital book-reader) READS the mRNA's (the thing from the earlier process of transcription, i.e. rewriting) sequence of bases it has copied EXACTLY from the aforementioned gene in the process of REWRITING
3) Here it can get a bit tricky. Remember that a CODON is a set of THREE nucleotides WITHOUT complementary bases with a distinctive sequence (i.e. three nitrogenous bases in a particular order e.g. Cytosine (C)-Guanine (G)-Adenine (A))
4) TRANSFER RNA (tRNA) now comes into play. tRNA is the little worker, if you will. The tRNA floats around in the CYTOPLASM (i.e. not in the nucleus nor the ribosome). It holds an amino acid (on its back; like an ant with a bread crumb) and contains a CODON sequence that is COMPLEMENTARY to the mRNA molecule (earlier I used the sequence C-G-A for the mRNA (in step 3); this means the Codon of the tRNA would be G-C-U (remember U stands for URACIL, which is THYMINE in terms of RNA - a bit confusing, but just remember Uracil is the substitute for Thymine here)
5) the tRNA bonds with the mRNA (which is bonded to the Ribosome). The tRNA lets go of its amino acid, which attaches itself to the Ribosome - this will eventually be a POLYPEPTIDE - remember a polypeptide is a chain of amino acids)
6) The Ribosome (e-book reader) continues to move along the mRNA, 'reading' the rest of the gene i.e. it reads the NEXT Codon (a set of three nitrogenous bases in a SPECIFIC order) - this may be different to the earlier C-G-A sequence of the mRNA, which will mean a different tRNA will be attracted to the mRNA with a DIFFERENT amino acid. The tRNA will again bond to the mRNA (which is bonded to the Ribosome still) and release its particular amino acid. This will join with the previous amino acid (from step 5). This process happens again and again until the whole gene is expressed as amino acids. Eventually, this will be a POLYPEPTIDE (a sequence of amino acids).
So what is the the process by which DNA controls the production of polypeptides you ask? Transcription (rewriting) and translation; the DNA (which contains genes) is copied in the nucleus --> mRNA takes to Ribosome --> mRNA bonds to Ribosome --> Ribosome (e-book reader) 'reads' the base sequences (which have been copied EXACTLY from the gene) --> tRNA COMPLEMENTARY to the codon (remember, a codon is a sequence of three nitrogenous bases, which may be in ANY order) of the mRNA brings its OWN SPECIFIC amino acid to the Ribosome --> Bonds to mRNA (which is bonded to the Ribosome) --> tRNA lets go of its PARTICULAR amino acid --> These processes happens again and again --> Eventually a POLYPEPTIDE (a sequence of amino acids) is formed.
Hence, DNA controls the production of polypeptide synthesis through the processes of transcription (rewriting) and translation, which ultimately dictate the particular amino acids to be coded for. In turn, these comprise the final product - the polypeptide.
#Uneditedandlate #offthetopofmyhead
no h8
As for the model, there are a plethora of them online. I do recommend applying the steps I have explained above to a visual representation. Ultimately, a visual representation is facilitative of a complex comprehension of this concept - something which is imperative to succeed in HSC Biology (plus the BOS wants you to be able to model it, lol).
Best of Luck.
When I was explaining it to my friend (and others) I found the main difficultly encountered was comprehending the meaning of transcription and translation (I am serious).
Think of transcription as REWRITING (because it is, lol). This occurs in the NUCLEUS.
What happens here is:
1) The double stranded DNA unwinds itself, exposing a section of a gene that is to be expressed, i.e. a particular section that codes for an amino acid (which in turn makes/comprises a polypeptide)
2) RNA polymerase (an enzyme) moves along this gene (the unwound bit of the DNA), attaching loose RNA nucleotides (a phosphate, a sugar and a nitrogenous base). Remember that nitrogenous bases only pair COMPLEMENTARY - adenine with thymine and cytosine with guanine. This ensures the gene is copied EXACTLY. Note here that thymine (the nitrogenous base) is replaced with uracil (why, you ask? Because YOLO; but in all seriousness, you don't need to know why - you just need to know this happens). Uracil acts EXACTLY like thymine - that is, it will ONLY pair with adenine (this means thymine is not present when DNA is expressed - or REWRITTEN - in terms of RNA).
3) Once this gene is copied, the matured RNA moves outside of the nucleus, and makes its way to the RIBOSOME (it moves out to the cytoplasm first and makes it way to the ribosome). It is now know as MESSENGER RNA (mRNA).
Okay, now translation occurs. Think of translation, as well, translation. The overarching idea here is that the mRNA's specific sequence (from copying the base sequence of the aforementioned gene EXACTLY) here is TRANSLATED in terms of amino acid. These amino acids THEN go on to form a polypeptide (remember many amino acids can comprise a polypeptide and many polypeptide can comprise a protein - or an enzyme). Then you have a polypeptide, yay.
The process is as follows:
1) The mRNA bonds with the Ribosome because the mRNA hasn't been friend-zoned. Think as the Ribosome as an e-Kindle or whatever the fuck the digital book-readers are called.
2) The Ribosome (digital book-reader) READS the mRNA's (the thing from the earlier process of transcription, i.e. rewriting) sequence of bases it has copied EXACTLY from the aforementioned gene in the process of REWRITING
3) Here it can get a bit tricky. Remember that a CODON is a set of THREE nucleotides WITHOUT complementary bases with a distinctive sequence (i.e. three nitrogenous bases in a particular order e.g. Cytosine (C)-Guanine (G)-Adenine (A))
4) TRANSFER RNA (tRNA) now comes into play. tRNA is the little worker, if you will. The tRNA floats around in the CYTOPLASM (i.e. not in the nucleus nor the ribosome). It holds an amino acid (on its back; like an ant with a bread crumb) and contains a CODON sequence that is COMPLEMENTARY to the mRNA molecule (earlier I used the sequence C-G-A for the mRNA (in step 3); this means the Codon of the tRNA would be G-C-U (remember U stands for URACIL, which is THYMINE in terms of RNA - a bit confusing, but just remember Uracil is the substitute for Thymine here)
5) the tRNA bonds with the mRNA (which is bonded to the Ribosome). The tRNA lets go of its amino acid, which attaches itself to the Ribosome - this will eventually be a POLYPEPTIDE - remember a polypeptide is a chain of amino acids)
6) The Ribosome (e-book reader) continues to move along the mRNA, 'reading' the rest of the gene i.e. it reads the NEXT Codon (a set of three nitrogenous bases in a SPECIFIC order) - this may be different to the earlier C-G-A sequence of the mRNA, which will mean a different tRNA will be attracted to the mRNA with a DIFFERENT amino acid. The tRNA will again bond to the mRNA (which is bonded to the Ribosome still) and release its particular amino acid. This will join with the previous amino acid (from step 5). This process happens again and again until the whole gene is expressed as amino acids. Eventually, this will be a POLYPEPTIDE (a sequence of amino acids).
So what is the the process by which DNA controls the production of polypeptides you ask? Transcription (rewriting) and translation; the DNA (which contains genes) is copied in the nucleus --> mRNA takes to Ribosome --> mRNA bonds to Ribosome --> Ribosome (e-book reader) 'reads' the base sequences (which have been copied EXACTLY from the gene) --> tRNA COMPLEMENTARY to the codon (remember, a codon is a sequence of three nitrogenous bases, which may be in ANY order) of the mRNA brings its OWN SPECIFIC amino acid to the Ribosome --> Bonds to mRNA (which is bonded to the Ribosome) --> tRNA lets go of its PARTICULAR amino acid --> These processes happens again and again --> Eventually a POLYPEPTIDE (a sequence of amino acids) is formed.
Hence, DNA controls the production of polypeptide synthesis through the processes of transcription (rewriting) and translation, which ultimately dictate the particular amino acids to be coded for. In turn, these comprise the final product - the polypeptide.
#Uneditedandlate #offthetopofmyhead
no h8
As for the model, there are a plethora of them online. I do recommend applying the steps I have explained above to a visual representation. Ultimately, a visual representation is facilitative of a complex comprehension of this concept - something which is imperative to succeed in HSC Biology (plus the BOS wants you to be able to model it, lol).
Best of Luck.
Last edited:
bangladesh
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As others have explained, the process is extremely easy once you understand it. Try and not memorise it and actually understand it, that way you won't have to cram it before the exam. It's been explained above so I won't explain again but just try and UNDERSTAND as much concepts as you can rather than just memorising them.