In my biology class, we’re learning about gene regulation/expression and transcription of a gene.
I sort of understood what gene regulation is, but I still don’t understand the steps that go with the process and what transcription is along with what is the purpose of that. I also don’t understand the clear difference between needing mRNA to be synthesized through DNA?
I appreciate your help.
In: Biology
I learn’t this in french so I might nit be able to say it clearly
basically genes are part or fragments of ur DNA that will be converted into proteins the process of going from DNA to proteins is your mRNA
Hope i could help any questions just ask
The overall purpose of DNA is that it is many times more stable than RNA, which allows for more complex organisms.
The double strand of the DNA structure means that when a nucleic acid is damaged then the whole structure is compromised and it can be repaired or destroyed before it goes on to encode a protein that may be ineffective or harmful.
When it comes time to actually create a protein for your body though DNA is far too massive. It contains instructions for every single protein in your body. So a small piece of DNA is copied onto a strand of RNA and that RNA strand will contain only the instructions for the specific protein that needs to be made.
Think of DNA as a physical cookbook that contains 200,000 recipes. The book is way to big to move around but there are many cooks that need that information to do their jobs. RNA is a copy of a single recipe that is delivered to the cook who needs the information.
Hello, first year biochem student here so this is my very rudimentary explanation. We need messenger RNA (mRNA) to get the information stored on DNA (the gene) to a ribosome in the cytoplasm. For example, in prokaryotes they do not need mRNA to transport that information to a ribosome bc there is no nucleus only a nucleoid region and the ribosome can attach directly to the DNA. So, the reason why a eukaryotic cell needs mRNA is to transport that gene to a ribosome for translation (to turn it into a protein). As for the steps or transcription, a very basic rundown is that a piece of mRNA is synthesized from a section of DNA using RNA polymerase. The introns are spliced out. That mRNA strand is fitted with a 5’ 7 methyl Guanasine cap and a 3’polyA tail to protect it. It then passes through the nuclear membrane and finds a ribosome.
DNA is like a big library where all the instruction books needed to build your body are stored. The library doesn’t make things though, it just stores the books. In order to make things you need a factory and the factory needs a way to get books from the library so that it knows how to make things. The Cell Nucleus is the library and the Ribosoms are the factories. The go-between that gets books from the library to take to the factory is called [messengerRNA](https://en.wikipedia.org/wiki/Messenger_RNA) (mRNA). The Ribosoms also have another helper called transferRNA (tRNA) whose job it is to get the materials the factory needs to actually build the proteins. So mRNA transfers an instruction manual, and tRNA brings the necessary building blocks that match the instructions and the Ribosoms assemble them together to make proteins.
[Gene Regulation](https://www.khanacademy.org/science/biology/gene-regulation/gene-regulation-in-eukaryotes/a/overview-of-eukaryotic-gene-regulation) is how your cells decide what proteins to build. Your liver cells do very different things from your brain cells, how do they know what to do? The DNA in both cells is exactly the same!
You can think of gene expression like a librarian at the library locking up some books, and making others available to the mRNA. The librarian learns what books to make available based on messages she gets from outside the cell that tell her what sort of environment she is in. If the cell is surrounded by liver cells, for example, that cell librarian will also make her books available for building liver cell proteins and so the Ribosoms will build liver-cell proteins and not others.
It gets more complicated when we start to talk about how a cells “becomes” a certain kind of cell. I don’t know if your biology course has covered that yet. In short, if a cell divides from another mature cell it will usually be the same kind of cell because the Nucleus will inherit the cellular structure of the parent. So a liver cell will divide to produce another liver cell. However, there are also cells called “[stem](https://stemcells.nih.gov/info/basics/1.htm)” cells that have no “type” to them at birth. These cells can become any type of cell in your body, and they know what type to become from the environment where they find themselves. A stem cell in your brain that comes to rest near a dead neuron will likely turn into a new neuron, for example.
The DNA is like a long keyboard. Depending on which buttons, or “genes” you press, different things happen to cells. Cells can do many things by transforming some molecules into other molecules, in sequences called “biological pathways”. These pathways allow cells to do many things, including helping cells differentiate and organise to become tissues (skin, bone, muscle…), organs, organisms and then… u/Individual_Cobbler.
How you do this? With “gene” regulation. In the same way as on the piano you play specific notes in a specific sequence for a certain duration, cell metabolism is regulated by making sure that those DNA buttons, “genes”, are pressed for the right amount of time, and in the right combination.
But what happens when you “press” a button? Each “gene” does not work on its own: it has to become something else, in the same way as milk has to become cheese. And, like France and Italy, cells have many different types of cheese. Some of these are called “proteins”, some are called “RNA transcripts”. Normally, a “gene” DNA template can’t produce any camembert. To make cheese, molecular machinery first produces a “RNA transcript”, and then the “RNA transcript” is “translated” into a “protein”. In other words, there are different flavours of camembert.
These transcripts and proteins can help press the right buttons on the keyboard. How? By “covering” the buttons, and preventing the cell to play them. Imagine having your keyboard covered in camembert: nobody would like to play it, right? This is what gene regulation is: covering specific buttons in cell’s genetic keyboard with camembert, so that only other buttons will be played at a given time. Different RNA transcripts and proteins play different roles, at specific times, in pressing the keyboard buttons, covering buttons in camembert and removing all that delicious cheese.
tl;dr life is a box of camembert
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