Molecular Genetics Flashcards
What are nucleotides?
Basic unit of DNA. It contains deoxyribose sugar, a phosphate group, and a nitrogenous base (adenine, cytosine, guanine and thymine).
How do nucleotides bond together?
A - T
C - G
By hydrogen bonds.
What is transcription?
Transcription is the process by which DNA is used to make mRNA.
What is translation?
Translation is the process by which the sequence of mRNA codons is used to make a polypeptide.
How does transcription work?
The region of DNA carrying the gene unwinds and unzips, separating the two DNA strands.
One of the DNA strands will be used as a template.
[Censored biotech stuff]
Wow mRNA is formed
How does translation work?
The ribosome translates the message in mRNA into a sequence of amino acids joined together to form a polypeptide.
As the ribosome moves along the mRNA, the polypeptide produced gets longer as more amino acids are joined together by peptide bonds.
At the end of the mRNA strand, the ribosome detaches from the mRNA, and the polypeptide is released.
What is genetic engineering?
Genetic engineering is a technique used to transfer genes from one organisms to another. Individual genes may be cut off from the cells of one organism and inserted into the cells of another organism of the same or different species. The transferred gene can express itself in the recipient organism.
How is a gene transferred to a bacterium?
Cut a gene using a restriction enzyme.
Obtain a plasmid and cut it using the same restriction enzyme.
Mix the plasmid with the DNA fragment containing the gene.
Add DNA ligase to seal the gene to the plasmid.
Mix the recombinant plasmid to the bacterium.
How is a gene transferred to a plant?
Cut a gene using a restriction enzyme.
Obtain a plasmid and cut it using the same restriction enzyme. (Biotech - Ti plasmid)
Insert the gene into the plasmid and the plasmid into the bacterium.
Allow the bacterium to infect the plant cells. Once inside the plant cells, the gene will be inserted into the plant chromosome.
What are the benefits of genetic engineering?
Low cost
- Helps make important drugs more affordable
Can produce crops that grow in extreme conditions
- Helps farmers grow crops even when environmental conditions are not suitable
Development of pesticide resistant crops
- Helps reduce the use of costly pesticides
Development of foods designed to meet specific nutritional goals
- Helps improve nutritional quality of foods
What are the social and ethical issues of genetic engineering?
- Allergies
- Toxic/cancer causing
- Loss of biodiversity
- Animal exploitation
- Biological warfare
- May reduce effectiveness of antibiotics
- Social class distinctions
