Gene Technology Quiz

Study Notes

Gene Technology

Gene technology is a significant advancement in science since the discovery of DNA's structure in 1953.
Genetic engineering (also known as recombinant DNA technology) involves manipulating genes, including synthesizing, removing, altering, and transferring them between organisms.
Organisms with introduced DNA exhibit altered characteristics, a result of direct gene alteration or the transfer of genes from another organism.
Recombinant DNA occurs when DNA from two different sources is combined.
An organism containing recombinant DNA is called a genetically modified organism (GMO).
An organism used to produce a protein product from transferred DNA is called a recombinant host.
Transferred DNA is sometimes referred to as foreign DNA or foreign gene.

Applications of Gene Technology

Gene technology addresses human diseases caused by the inability to produce certain metabolic chemicals, often proteins like insulin.
Techniques have been developed to produce large quantities of "pure" proteins through gene isolation, cloning, and transfer into microorganisms.
Microorganisms act as "factories" for continuous protein production.

Stages of Protein Production

Transformation: Transfer of DNA into suitable host cells.
Identification: Identifying host cells that have successfully taken up the gene using gene markers.
Large-scale Production: Growing a large population of host cells.

Gene Identification and Synthesis

Identifying and extracting the required gene, or synthesizing it, is crucial.
Genes can be synthesized using mRNA as a template or combining chemical and molecular biology methods to create short nucleotide sequences that are later joined.
The transferred DNA fragment might contain additional nucleotide sequences necessary for transcription.

Reverse Transcriptase

Retroviruses are a group of viruses, with HIV being the most well-known.
Retroviruses store their genetic information as RNA.
They synthesize DNA from their RNA using reverse transcriptase, an enzyme that catalyzes the production of DNA from RNA, the opposite of typical transcription.
Reverse transcriptase is used in genetic engineering to synthesize the required DNA.

Gene Synthesis using Reverse Transcriptase

A cell producing the desired protein is selected (e.g., insulin-producing cells from the pancreas).
mRNA is extracted from these cells, which contain large quantities of the relevant mRNA.
Reverse transcriptase is used to convert RNA into DNA, creating complementary DNA (cDNA).
DNA polymerase is used to build the complementary nucleotides on the cDNA template, generating a double strand of DNA, the required gene.
This method exploits the abundance of mRNA and its easier extraction compared to the gene.
It also avoids the need for bacteria to process RNA transcripts with non-coding portions of DNA.

Restriction Endonucleases

Bacteria often defend against invading viruses by producing enzymes called restriction endonucleases that cut up viral DNA.
Various types of restriction endonucleases exist, each recognizing and cutting at a specific sequence of bases called a recognition sequence.
Restriction endonucleases can cut DNA between two opposite base pairs, resulting in blunt ends.
They can also cut DNA in a staggered fashion, creating sticky ends with exposed, unpaired bases.
These sticky ends have palindromic sequences, a characteristic of restriction endonuclease activity.
Sticky ends are important in gene technology because they enable the joining of DNA fragments.

Description

Test your knowledge on gene technology and its applications. This quiz covers topics such as genetic engineering, recombinant DNA, and genetically modified organisms (GMOs). Explore how these advancements impact human diseases and biotechnology.