These are some notes I took on DNA and RNA. Hope it helps :)
Just about every biochemical reaction that takes place in your cells is made possible by proteins. Proteins in the form of hormones send signals to your cells about what to do and when to do it. For example, the protein insulin helps cells control your blood sugar levels. Proteins in the retina of your eye, called rhodopsin, are what receive light and send that information along. Proteins in your blood, called hemoglobin, carry oxygen to every cell in your body. When something in your body needs to be done, proteins do it.
Proteins are assembled in the cytoplasm by ribosomes. DNA, which has all the genetic information needed to make these proteins, is located in the nucleus of a eukaryotic cell (or in the nucleoid of a prokaryotic cell).
So how does the information in DNA get translated into the actions of the proteins? How do the instructions get from the nucleus to the ribosome? The answer is RNA, or ribonucleic acid.
DNA makes RNA makes protein. This is the process by which genetic information in the nucleus gets translated into all the actions needed to keep your cells working and keep you alive. Let’s take a closer look at how this happens.
The genetic information in DNA is a kind of code. Each individual (except identical twins) has a unique DNA sequence, or code, and every cell in a multicellular organism has the exact same DNA sequence in its nucleus (with a few exceptions). The sequence of DNA determines the structure of the proteins made by the cell.
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Look at the simple code shown here. Each number stands for a letter of the alphabet. In this code, numbers represent letters. (The number 27 represents a space between letters.)
In the DNA code, different groups of chemicals represent the different building blocks of proteins.
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RNA Reads and Carries the Code
RNA is a molecule that is very similar in structure to DNA. In fact, RNA is so similar to DNA that RNA can store an exact copy of the information that is in a DNA sequence. RNA can then transport that copy of the information to the ribosomes.
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Ribosomes Use the Code
Once the RNA gets to the ribosomes, another kind of RNA reads the coded sequence and decodes it. It uses that information to string together the amino acids that are the building blocks of proteins. At the ribosome, the unique sequence of RNA (which is a copy of the DNA) is decoded into a unique sequence of amino acids to make a protein.
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DNA to RNA to Protein
The DNA in the nucleus (or nucleoid) contains all the instructions a cell uses to produce the proteins it needs.
The instructions in the DNA are transported from the nucleus to the ribosomes by RNA.
The instructions are used to assemble the cell’s proteins at the ribosomes.
You could say that the genetic information in the cell flows from DNA to RNA to protein.
