It contains genes, passed on from our parents, which construct our distinct features, e.g. Eye Colour, Hair Colour, Skin Colour etc. DNA must replicate in order to pass on the Genomes, the way this replication occurs is one DNA strand must act like a template and then it is copied to create a new strand which is an exact copy of the template. Protein is created by the information stored inside each gene’s DNA. The information is transferred to a molecule called Ribonucleic Acid (RNA).
Transgenesis and Cloning Transgenesis is the process of inserting a gene from one source into a living organism that would not normally contain the inserted gene. The gene can come from the same species (called Cisgenesis) or from a different species entirely. To facilitate the transfer of genes from one organism to another, often a Transgenic Organism with Recombinant DNA is created: -The first step in creating an organism capable of carrying out the transformation process is to isolate the required gene. This is done so using Restriction Enzymes, which target a specific gene sequence. The gene is often cut with staggered ends, called “Sticky Ends” which only allow specific and complementary gene sequences bond by base pairing.
This is the restriction enzyme and acts as “molecular scissors” cuts the two DNA chains at a specific area in the genome so that sections of DNA can be supplemented or detached. A piece of RNA known as guide RNA is the second key molecule. This consists of pre-designed RNA quite small in length sequence, consisting of about 20 bases, positioned within a longer RNA scaffold. The scaffold binds to DNA and the pre-designed sequence ‘guides’ Cas9 to the right part of the genome. ensuring that the Cas9 enzyme intersects at the right point in the genome.
Aurora kinases are involved in this checkpoint function. These kinases are only expressed during mitosis and overexpressed in a wide range of tumours. Aurora A is thought to play a role in regulating centrosome function. At the spindle checkpoint, Aurora B plays an essential role in recruiting proteins such as baba1 to the kinetechores. This promotes chromosome alignemtne, and ensures each daughter cell receives the correct number of chromosomes, The eukaryotic cell cycle is divided into several phases - G1, S, G2 and M. Chromosomal DNA replication takes place during S phase, whereas cell division (mitosis and cytokinesis) occurs
When cells need to divide, the cells have to replicate and copy its entire DNA so that each daughter cell gets one complete set of genetic information. The hydrogen pairs that are holding together the base pairs are broken by enzymes, like helicase, and the molecule is split in half creating two strands. This process is also called the “unzipping process”. These two strands have to follow the rules of base pairing. Each strand serves as a template for the attachment of complementary bases.
Enzymes called topoisomerases produce breaks in the DNA molecules and then reconnect the strands, relieving strain and effectively preventing tangling and knotting during replication. DNA polymerase adds new nucleotides to a growing strand of DNA. Because DNA polymerase must adhere to an existing template, an RNA primer is first created at the site of replication. The RNA primer is synthesized by primase, an enzyme that is able to start a new strand of RNA opposite a DNA strand. After a few nucleotides have been added, the primase is displaced by DNA polymerase, which can then add subunits to the 3’ end of the short RNA primer.
Synthesis, processing, and functionThe brief existence of an mRNA molecule begins with transcription and ultimately ends in degradation. During its life, an mRNA molecule may also be processed, edited, and transported prior to translation. Eukaryotic mRNA molecules often require extensive processing and transport, while prokaryotic molecules do not.  TranscriptionMain article: Transcription (genetics) Transcription is when DNA makes RNA. During transcription, RNA polymerase makes a copy of a gene from the DNA to mRNA as needed.
A ribosome can also be known as the chemical factory. Messenger ribonucleic acid (mRNA) has the job of making copies of parts of the DNA as required by the body and taking it through the chemical factory. So in relation to the topic of this essay, a messenger mRNA comes along and takes a copy of a digestive enzyme from the DNA and squeezes through the pores with it into the cytoplasm . In this environment it heads towards the ribosomes and passes through the ribosome where protein synthesis and translation occurs. The protein then passes to the Golgi apparatus where it is processed and packaged or more simply modified and labelled for its digestive function then released in vesicles to go and perform its specific function.
The smaller plasmids make use of the host cell’s own DNA replicative enzymes in order to make copies of themselves, whereas some of the larger ones carry genes that code for special enzymes that are specific for plasmid replication. Size and copy number of plasmid is an important feature of plasmids for cloning purpose e.g. plasmid ranging from 6-10 Kb is very suitable for cloning and having copy number as many as 50. Plasmid may be of following type: • F-Plasmid: having ability to promote conjugal transfer of plasmid e.g. F-Plasmid of E.coli • R-Plasmid: responsible for providing resistance to host against foreign bodies such as anti bacterial resistance e.g.