Recombinant DNA technology

this technology involves the combination of DNA from one organism with DNA from another organism. Often this involves inserting human DNA into the DNA of another organism. when these genetically engineered organisms are cultured, they produce human protein

every cell in the human body contains 46 chromosomes and each chromosome can contain several thousand genes. the first task is to isolate the gene that we want to use. there are 3 ways to separate the gene:

STEP1-Working backwards from the protein- first we must workout the the amino acid sequence for the protein we wish to make. once we know this, we can use the genetic code to work out the base sequence that would code for the protein. we then make the DNA with that base sequence.

STEP2-Using messenger RNA- when cells make a protein, they first transcribe its gene into a molecule of mRNA. the messenger RNA molecules carrying the code for insulin are common in the cytoplasm of insulin-producing cells