Nucleic Acid Structure: Similarities And Differences

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Nucleic Acid

Structure

Similarities

Differences

DNA

It has a double helix structure with phosphate and sugar molecules along the side and the nitrogenous bases up the centre which include adenine cytosine thymine and guanine.

DNA and RNA are both found inside the nucleus. Like DNA, RNA is a linear polymer made of four different types of nucleotide subunits linked together by phosphodiester bonds

DNA is the only double stranded nucleic acid. DNA is also only found in the nucleus and there is only has one type. DNA also has a nitrogenous base called thymine.

rRNA

rRNA is made up of a chain consisting of between 100 to 3000 nucleotides, these chains are made inside the nucleus of a cell, it also associates with

Transcription makes a copy for RNA of a DNAs gene sequence for a protein-coding gene. The RNA copy carries the information needed to build a polypeptide an RNA copy can also be called a transcript. These Transcripts go through many other steps before it is translated into proteins. The transcription of a gene takes place in three stages: initiation, elongation, and termination. The Initiation stage is when RNA polymerase attaches onto a sequence of DNA called the promoter which is found at the beginning of a gene, each gene has its own promoter. Once the RNA polymerase is attached onto the promoter, the RNA polymerase then separates the DNA strands, making the single-stranded template needed for transcription, which contains recognition sites for RNA polymerase or its helper proteins to bind to. The DNA opens in the promoter region so that RNA polymerase can begin transcription. The next step is Elongation which is when the template strand acts as a template for RNA polymerase, as it reads this template one base at a

The RNA transcript carries the same information as the non-template strand of DNA, but it contains the base uracil instead of thymine. The last step is termination, this is when sequences called terminators signal that the RNA transcript is complete. Once they are transcribed, they cause the transcript to be released from the RNA polymerase.

Translation is the last step all together on the way from DNA to protein. It is when the synthesis of proteins is directed by a mRNA template. The information contained in the nucleotide sequence of the mRNA is read as triplets, called codons. Each word stands for one amino acid.

During translation amino acids are linked together to form a polypeptide chain which will later be folded into a protein. The translation is dependent on many components, two are very important. First, the ribosome which is the cellular factory is responsible for the protein synthesis, it consists of two different subunits, one small and one large and is built up from rRNA and proteins. Inside the ribosome the amino acids are linked together into a chain through multiple biochemical