Protein synthesis

[Sa1998]

I always mix this process up. Please help!!!!
Much appreciated.

[vox nihili]

I always mix this process up. Please help!!!!
Much appreciated.

Tell us what you know first so we can see where you're at

[naomisirmai]

SO...
Protein synthesis is about making proteins from your DNA...

It takes place in 2 stages - transcription (where DNA is converted into mRNA) and then translation (where mRNA and tRNA combine to make a polypeptide). A bunch of polypeptides make a protein.

To go into detail;

Transcription: DNA -> mRNA
1. DNA unwinds and unzips
2. RNA polymerase links complementary RNA nucleotides to the unwound DNA – forming an mRNA strand
3. mRNA strand is modified so that it contains only exons (regions that code for proteins)
4. mRNA moves from the nucleus of the cell into the cytoplasm[/li][/list]

Translation: mRNA + tRNA -> polypeptide -> protein
5. mRNA binds to a ribosome
6. tRNA carrying anticodons binds to mRNA’s codons
7. A polypeptide chain is formed until a ’stop’ codon is reached
8. Newly formed polypeptide chain is released into the cytoplasm

It always occurs in this order. If you have faulty or mutated DNA, you'll end up with a different polypeptide produced!

Does this all make sense?

[jamonwindeyer]

SO...
Protein synthesis is about making proteins from your DNA...

It takes place in 2 stages - transcription (where DNA is converted into mRNA) and then translation (where mRNA and tRNA combine to make a polypeptide). A bunch of polypeptides make a protein.

To go into detail;

Transcription: DNA -> mRNA
1. DNA unwinds and unzips
2. RNA polymerase links complementary RNA nucleotides to the unwound DNA – forming an mRNA strand
3. mRNA strand is modified so that it contains only exons (regions that code for proteins)
4. mRNA moves from the nucleus of the cell into the cytoplasm[/li][/list]

Translation: mRNA + tRNA -> polypeptide -> protein
5. mRNA binds to a ribosome
6. tRNA carrying anticodons binds to mRNA’s codons
7. A polypeptide chain is formed until a ’stop’ codon is reached
8. Newly formed polypeptide chain is released into the cytoplasm

It always occurs in this order. If you have faulty or mutated DNA, you'll end up with a different polypeptide produced!

Does this all make sense?

Wow! Aren't you the NSW Bio Lecturer?? Omg can I have an autograph? 

[Sa1998]

Yes this makes so much sense thank you!!!

[naomisirmai]

Wow! Aren't you the NSW Bio Lecturer?? Omg can I have an autograph? 

So I've heard!
You can have an autograph if you're lucky

[naomisirmai]

Yes this makes so much sense thank you!!!

Ah great, I'm so pleased! Good on you for making sure you understand.

[ehatton2016]

Strongly recommend drawing protein synthesis, for example on a whiteboard over and over until it sticks. I hate this section and always get it confused with DNA replication. We did a model using pipe cleaners and pom poms at school, but it was such a wast of time, so much better to draw it.

Hope this is helpful!!

[naomisirmai]

Strongly recommend drawing protein synthesis, for example on a whiteboard over and over until it sticks. I hate this section and always get it confused with DNA replication. We did a model using pipe cleaners and pom poms at school, but it was such a wast of time, so much better to draw it.

Hope this is helpful!!

Can confirm! Here's my drawing of protein synthesis - make your own in a way that you understand!

[CinnamonTea]

Naomisirimai is spot on offcoarse, the only detail I like to add to enhance my understanding is that transcription occurs in nucleus and translation in the cytoplasm

[vox nihili]

And also to avoid any confusion, the stop codon is not part of the polypeptide but rather of the mRNA

[aaron_solomon]

can someone please explain to me the relationship between proteins and polypeptides, i know that polypeptides make up proteins but is there any more to that dot point that i should know?

[stephanieazzopardi]

can someone please explain to me the relationship between proteins and polypeptides, i know that polypeptides make up proteins but is there any more to that dot point that i should know?

Proteins are made up of amino acids bonded together by peptide bonds. A polypeptide consists of two or more amino acids. Therefore a protein is developed from a series of polypeptide chains. And without polypeptides, you wouldn't have a protein. That's how they're related. 

[jamonwindeyer]

Proteins are made up of amino acids bonded together by peptide bonds. A polypeptide consists of two or more amino acids. Therefore a protein is developed from a series of polypeptide chains. And without polypeptides, you wouldn't have a protein. That's how they're related. 

OMG aren't you the General Math lecturer?? Can I have an autograph! 

[stephanieazzopardi]

OMG aren't you the General Math lecturer?? Can I have an autograph! 

Sorry, I don't give out my snazzy autograph to randoms. Especially the Mathematics lecturer