The code contained in a particular gene results in the production of a particular what? Would it be a protein? Or an amino acid?
The code in the gene is transcribed to mRNA in the nucleus which then goes into the ribosomes where tRNA comes and attaches to the mRNA. Which tRNA bonds is dependant on the nitrogen bases the mRNA codes for. Amino acids are attached to the tRNA and when the tRNA bonds to the mRNA, the amino acids bond together creating a polypeptide chain which is a protein. Multiple tRNA bond to the mRNA. In short, the amino acids bond together creating a protein
But they form amino acids first, right? Like.. like Leucine and such?
So it results in a phenotype?
Amino acids are attached to the tRNA and aren't produced by the genes, the genes determine which order they are when they make a chain. Depending on which order they are in will determine the protein made Phenotypes are expressed by amino acids bonding together to make proteins.
I have a A+ in biology and was just spent the entire night studying this stuff
Okay. I'm just really confused. I'm sorry.
You know that DNA has nitrogen bases and that during transcription, the RNA polymerase essentially makes a copy of the sequencing of the bases right?
And that on the RNA strand that the RNA polymerase made, there are codons (groups of three nitrogen bases)
Yes, hang on slow down. In transcription, if the DNA sequence was AGC then the RNA would be UCG?
Correct! tRNA (which just floats around in the cytoplasm), enters the ribosome along with the newly made mRNA. The tRNA contains codons, and it matches up to the codon on the mRNA. So if the mRNA has UCG, the corresponding tRNA has AGC. So they attach and the amino acid that was attached to the tRNA is added to the chain. Lets say the next codon on the mRNA was UAU, then the corresponding tRNA would be AUA, and the amino acid that was attached to first tRNA would attach to this one.
To figure out which amino acid is added to the chain, use to mRNA codon
So the tRNA and the mRNA are the things that hook up to each other? Well, the codons from tRNA and mRNA anyway. So they hook together and when they're all hooked up, that's what ends up making a new DNA molecule?
No, the DNA molecule is already made. The mRNA is essentially a copy of the DNA. What mRNA and tRNA molecule make is a chain of amino acid (polypeptide chain) which is a protein.
Ohhhh!!! Okay okay, so.. the mRNA is a copy of the DNA. So if the DNA sequence was TCG, then the mRNA would be TGC, and then that would hook up with tRNA? I'm sorry for being so frustrating, I am just.. stupid concussions.
The mRNA would be ACG. Also, RNA doesn't contain T, it has U instead. So if the DNA was AGA then the RNA would be UCU. Don't worry about it! I had a hard time understanding this stuff too and spent an entire night just trying to figure transcription and translation out. Its not easy stuff
Oh crap, I forgot that tRNA was RNA (duh..) So let's try this again. If the DNA sequence was ACG then the RNA would be UGC. I've got that much. So would that RNA (the UGC I just mentioned) be the tRNA?
To figure out tRNA, take the DNA sequence (ACG) turn it into RNA (UGC) then figure out the corresponding nitrogen bases (ACG). The tRNA sequence is basically the same as the DNA sequence except when the DNA has a T in which case the tRNA has a U. So if the DNA is ACT, the tRNA would be ACU
You have to change it and then change it again. That's right!
Correct! If you have any more questions feel free to ask
Okay. So the DNA (AGT) gets changed to RNA (UCA) and then gets changed to tRNA (AGU). Then the tRNA floats to.. the nucleus?
That is right. It doesn't go to the nucleus, it just exits the ribosome into the cytoplasm
Well what does it do then? The mRNA brings the DNA from the Nucleus, right? And where does it bring it?
The mRNA is a strand that is a copy of the DNA. The DNA can't exit the nucleus, but the mRNA strand can. The mRNA strand exits the nucleus and goes into the ribosome where it meets up with the tRNA.
Oh! And then the mRNA and the tRNA combine?
Yes! Then when they are done bonding, and the amino acid has joined a chain, the mRNA and tRNA exit the ribosome. The bond between them breaks, and the tRNA goes and gets attached to another amino acid so that it can start the cycle over again
Ohh! I think i get it!!
Awesome! And like I said, if you have any other biology related questions, feel free to send me a message!
So did you finish it ??
Finish what?
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