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DNA

In DNA, what determines how many of each protein are made? I understand that genes provide the genetic code for specific bases but is there a sequence that also codes for how many are made?
I'm a little confused when you say how much 'protein' is made, firstly do you mean amino acids, don't forget that Amino Acid chains are synthesised from the codons from bases in DNA that then fold into proteins. Well, wouldn't the length of the strand of mRNA also determine how many amino acids are made that fold into a protein/ proteins. Transcription is where the specific sections of DNA are read and mRNA is synthesised which is then Translated in the Ribosomes. Three bases, also known as a Codon, code for a specific amino acid. Some codons, are also known as STOP codons, for example UAA, and it basically does as the name suggests. It stops the translation of mRNA, therefore no more amino acids are synthesised.

To basically summarise:
Length of Amino acid chain depends on mRNA length and how many codons are translated
The presence of STOP codons tell protein synthesis to STOP

Hope that simple quick explanation helped in some way :smile:
Reply 2
Original post by ALikesGeetars
I'm a little confused when you say how much 'protein' is made, firstly do you mean amino acids, don't forget that Amino Acid chains are synthesised from the codons from bases in DNA that then fold into proteins. Well, wouldn't the length of the strand of mRNA also determine how many amino acids are made that fold into a protein/ proteins. Transcription is where the specific sections of DNA are read and mRNA is synthesised which is then Translated in the Ribosomes. Three bases, also known as a Codon, code for a specific amino acid. Some codons, are also known as STOP codons, for example UAA, and it basically does as the name suggests. It stops the translation of mRNA, therefore no more amino acids are synthesised.

To basically summarise:
Length of Amino acid chain depends on mRNA length and how many codons are translated
The presence of STOP codons tell protein synthesis to STOP

Hope that simple quick explanation helped in some way :smile:

Thank you for your reply.

I understand how the length of the amino acid chain is dependant on the number of bases between STOP codons in mRNA but I am confused how the body knows how many times to replicate this sequence of amino acids to make 'x' amount of polypeptides that become proteins. Not sure if that makes more sense now
Original post by aque1408
Thank you for your reply.

I understand how the length of the amino acid chain is dependant on the number of bases between STOP codons in mRNA but I am confused how the body knows how many times to replicate this sequence of amino acids to make 'x' amount of polypeptides that become proteins. Not sure if that makes more sense now

So you mean, for example, how come your mouth doesn't overflow with amylase if the cells have plenty of amino acids available?

I think a full answer to this question would probably have to be long and complicated, but part of the answer is that some genes have the capacity to be temporarily repressed.

Are you familiar with the lac operon? You might like to read about that.
It's all on ya jeans :gangster:

OMG I am 2 funneh
Original post by aque1408
Thank you for your reply.

I understand how the length of the amino acid chain is dependant on the number of bases between STOP codons in mRNA but I am confused how the body knows how many times to replicate this sequence of amino acids to make 'x' amount of polypeptides that become proteins. Not sure if that makes more sense now

Ahh that makes more sense now. Also, as mentioned by Trumbles, some genes such as the lac operon can be suppressed or stimulated. Essentially, the lac operon was discoveredwhen scientists were studying the metabolism of Lactose in the E. coli bacterium. How it works is that when there is lactose present, the lactose binds to whats called the repressor on the lac operon causing it to detach from the operon allowing RNA polymerase to transcribe the genetic material in order to produce the enzymes required to break down the lactose. Once there is very little or no lactose present, the repressor can no longer detach from the operon and RNA polymerase can no longer transcribe the gene. A similar sort of concept also exists with the trp operon (Tryptophan).

To save you from reading a full explanation and from me typing out a long explanation, here's a link to a video: :smile:
https://www.youtube.com/watch?v=10YWgqmAEsQ
Original post by Allah's_Hijabi
It's all on ya jeans :gangster:

OMG I am 2 funneh


Here's one for you: Wanna know why they call me DNA Helicase? Because I want to unzip your genes (jeans) :colondollar:
Reply 7
Original post by Trumbles
So you mean, for example, how come your mouth doesn't overflow with amylase if the cells have plenty of amino acids available?

I think a full answer to this question would probably have to be long and complicated, but part of the answer is that some genes have the capacity to be temporarily repressed.

Are you familiar with the lac operon? You might like to read about that.

Thank you, been wondering about this for a while (hasn't come up in any biology course that I've done so far)
Reply 8
Original post by Trumbles
So you mean, for example, how come your mouth doesn't overflow with amylase if the cells have plenty of amino acids available?

I think a full answer to this question would probably have to be long and complicated, but part of the answer is that some genes have the capacity to be temporarily repressed.

Are you familiar with the lac operon? You might like to read about that.

Thank you, been wondering about this for a while (hasn't come up in any biology course that I've done so far)

Original post by ALikesGeetars
Ahh that makes more sense now. Also, as mentioned by Trumbles, some genes such as the lac operon can be suppressed or stimulated. Essentially, the lac operon was discoveredwhen scientists were studying the metabolism of Lactose in the E. coli bacterium. How it works is that when there is lactose present, the lactose binds to whats called the repressor on the lac operon causing it to detach from the operon allowing RNA polymerase to transcribe the genetic material in order to produce the enzymes required to break down the lactose. Once there is very little or no lactose present, the repressor can no longer detach from the operon and RNA polymerase can no longer transcribe the gene. A similar sort of concept also exists with the trp operon (Tryptophan).

To save you from reading a full explanation and from me typing out a long explanation, here's a link to a video: :smile:
https://www.youtube.com/watch?v=10YWgqmAEsQ

Thanks for the video (and sticking with my question) , makes so much more sense now!
From what I remember (so definitely check this) one gene doesn't always mean one protein

Multiple proteins can arise from one gene due to splicing of the mRNA, is this what you mean?

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