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Ch. 14 Molecular Genetics - Coggle Diagram
Ch. 14 Molecular Genetics
DNA Structure
Double helix structure made from 2 anti-parallel polynucleotide chains
Hydrogen bonds b/w complementary base pairs to hold the 2 strands together
4 Bases
Adenine and Thymine
Cytosine and Guanine
1:1 ratio in the whole DNA molecule
Each nucleotide contains a phosphate, a sugar mole, and a nitrogenous base
Loosely packed and coiled around proteins in the nucleus to form chromatin
Gene
Sequence of DNA nucleotides that control the formation of a single polypeptide
Sequence of Formation of polypeptides
The message in the gene formed is copied into a messenger RNA/mRNA
The mRNA travels from the nucleus to the cytoplasm and attaches itself to a ribosome
The ribosome moves along the mRNA and synthesizes a polypeptide
When the ribosome leaves the mRNA, the polypeptide is released
Transferring Gene of Interest
Recombinant DNA
Each side of a gene has a restriction site
The restriction enzyme recognize and cut the restriction site to form sticky ends.
DNA strands from the 2 different organisms are cut with the same restriction enzyme to form complementary sticky ends
The 2 DNA strands bind together due to complementary base pairing and are sealed with DNA ligase
Transgenic Bacteria
Each side of a gene has a restriction site
The restriction enzyme recognize and cut a section of DNA from the donor organism to form sticky ends.
Plasmid is cut with the same restriction enzyme to form complementary sticky ends
The 2 DNA strands bind together due to complementary base pairing between their sticky ends and are sealed with DNA ligase
Mix w/ recipient organism e.g. bacteria and apply heat/electric shock treatment to create temporary pores in the plasmid membrane that enable the recombinant plasmid to enter
Genetic Engineering
Transfer of genes from one organism to another. Transferred genes can express itself in the recipient organism
Both same or diff. species
Social and Ethical Implications of Genetic Engineering
Benefits
Low cost production of medicines
More affordable --> More accessible --> More patients can get treatment
Less use of chemicals e.g. pesticides
Use of costly pesticides that can damage the environment is reduced.
E.g. Bt gene can be inserted into plant gene that can kill certain pests using a certain toxin.
Produces crops w/ higher nutritional value
Produces crops that grow in extreme conditions
E.g. drought-resistant, salt-tolerant
Enables farmers to grow crops even when conditions aren't suited to cultivate most crops
Disadvantages
Produce unknown allergens in foods
Animal testing since they are usually used in genetic engineering experiments. Consideration of animal welfare to minimize any suffering during testing is essential.
Used for biological warfare
Produce genetically engineered seeds and sells them for high costs --> Financial difficulties for poor farmers and reduces equal accessibility