Unit 3.2 Genetic Engineering

genetic modification procedure

1: vector/plasmid is isolated, 2: dna containing gene of interest from a diff species is cleaved by enzyme into fragments, 3: desired gene is selected and inserted in plasmid, 4: plasmid is taken up by a cell such as bacterium, 5: cells with gene of interest are cloned with either two goals in mind to create and harvest A: copies of a gene or B: protein products of a gene

role of vectors in genetic engineering

self replicating DNA molecule used to transport foreign DNA into a cell

two types of vectors

shuttle (several species can move cloned sequences among various organisms plasmids), viral DNA ( accepts larger pieces of foreign dna than plasmids)

how recombinant DNA vectors are made

in vitro, vector dna taken up by cell in bacterium, then grown in culture to form clones to isolate

how DNA vectors are introduced into host cells

transformation (cells take up DNA from surrounding environment, chemical treatment can make cell types competent for this since regular cells cannot do this) or electroporation (electrical current to form microscopic pores in the membranes of cells for DNA to enter through, usually applicable to all cells), protoplast fusion (chemically removing cell wall allowing more direct access to plasma mem.), microinjection (glass micropipette punctures plasma membrane and injects dna), gene gun (dna in plant cells by using gene gun to shoot dna through thick cellulose walls)

competence

physiological state in which a recipient cell can take and incorporate a large piece of donor DNA

restriction enzyme

cut specific sequence of DNA, destroy bacteriophage DNA in bacterial cells, methylated cytosines in bacteria protect their own DNA from digestion, create blunt ends or staggered cuts (sticky ends)

biotechnology

application of microbiology, using microbes to make products such as food and chemicals

transgenic

cell or organism whose genome has been altered through artificial introduction of one or more foreign DNA sequences from another species.

recombinant

insertion or modification of genes to produce desired proteins

genetic engineering

inserting, deleting, or modifying genes with recombinant dna technology

ligase

joining of two molecules, in dna it makes covalent bonds to join dna strands together.

vector

carry new DNA to desired cells, able to self replicate, plasmids and viruses

argobacterium

Ti plasmid (integrates plant genome and causes a tumorlike growth, can be used to introduce rDNA into plant)