What is DNA ( detailed )
DNA is contained within nucleus in a long thread like structure called chromosomes
DNA is a polymer made up of monomers called nucleotides ( made up of ribose sugar, phosphate, and a nitrogenous base )
The 4 bases are Adenine, Thymine, Cytosine and Guanine
Nucleotides always bind with complementary base pairing, A-T, G-C, joined by hydrogen bonding
The nucleotides join together to form a polypeptide chain, 2 polypeptide chains join together to form a double helix called DNA
Protein synthesis
A gene is a section of a DNA/chromosomes that codes for a specific polypeptide
Only the template strand is used to make the protein, the code is always read in triplets
Each triplet determines one amino acids
The sequence of amino acid produced the protein
What is a mutation, what are two types (explain)
Mutation is a change in the DNA sequence
1. Harmful mutation: if there is a change in a triplet, which codes for a different amino acid, this can change the structure of the protein
Like in an enzyme, it could disrupt the active site
2. Silent Mutations: like if there is a change in the triplet, but the new triplet still codes for the same amino acid, then it’s a silent mutation
What is generic engineering
It is the modification of an organisms genetic material
In it you take a copy of a gene from one organism and insert that gene into another organisms DNA. This creates a genetically modified organism, which is also called as transgenic
Genetically engineering Bacterial cells
- The Useful gene is cut from DNA of an organism using a restriction enzyme, which cuts DNA in a staggered way, creating sticky ends ( short sections of unpaired DNA)
- The bacterial plasmid DNA is cut using same restriction enzyme (RE) creating sticky ends, using the same RE means the unpaired bases on the ends of plasmid is complementary to that on plasmid
- The useful gene and plasmid are mixed and the gene is inserted into plasmid, through hydrogen bonds formed between com based in the sticky ends
- DNA ligase is used to join the plasmid DNA and the gene together creating a recombinant plasmid
- The recombinant plasmid so then inserted into the bacterial cell, The plasmid acts a vector carrying the useful gene into the bacterial cell
- The bacterial cell can be cultured through cloning so multiple GM bacteria containing recombinant plasmid can be produced
Example of proteins produced through bacteria through GE
- hormones (insulin to treat diabetes)
- Enzymes ( rennin for producing cheese)
- Blood clotting factors (Factor VIII for treating hemophilia
- Antibiotics (penicillin)
Genetic Engineering of plants
- Plant cells do not have a plasmid like bacteria do
- Instead the bacteria Agrobacterium tumefaciens is used to make GM plants, they have a plasmid called Ti plasmid which is able to enter plant cell, when it is infected with bacteria
- Just like the previous example, plant cells are grown in culture and then develop into plants that contain the useful gene
Examples of GM plants
Pest resistance in Bt cotton
Disease resistance in bananas
What are 4 genetic engineering in medicine
- Producing medicine
- Producing vaccine
- Producing human like vaccine
- Reducing spread of diseases
