What are restriction enzymes AP Bio?
Restriction enzymes These are enzymes that cut DNA at specific recognition sites that are usually 4 to 8 base pairs in length. The sites are usually also palindromic, meaning they read the same forwards and backward. The restriction enzymes will also produce “sticky” or “blunt” ends.
How can recombinant DNA be identified?
In most cases, organisms containing recombinant DNA have apparently normal phenotypes. That is, their appearance, behavior and metabolism are usually unchanged, and the only way to demonstrate the presence of recombinant sequences is to examine the DNA itself, typically using a polymerase chain reaction (PCR) test.
What is the purpose of the LacZ gene in a plasmid?
What is the purpose of the LacZ gene in a plasmid cloning vector? The LacZ gene is a selectable marker. Acts as a reporter gene which encodes beta-galctosidase. Expression of the lacz gene causes bacterial host cells carrying pUC18 to produce blue colonies when grown on medium containing a compound Xgal.
Do plasmids replicate?
The plasmid is a small DNA molecule within a chamber that is physically separated from chromosomal DNA and can replicate independently .
What effect do restriction enzymes have on DNA?
Restriction enzymes cleave DNA at specific nucleotide sequences. Restriction endonucleases cleave double-stranded DNA. These enzymes are sequence specific, and each enzyme acts at a limited number of sites in DNA called recognition, or cutting, sites.
Why restriction enzymes are called so?
Restriction endonucleases are called so because they restrict the growth of bacteriophages by recognising and cutting DNA at specific sites.
What is the aim of restriction enzymes?
restriction enzyme, also called restriction endonuclease, a protein produced by bacteria that cleaves DNA at specific sites along the molecule. In the bacterial cell, restriction enzymes cleave foreign DNA, thus eliminating infecting organisms.
What do arrows on plasmid mean?
The arrows represent the location and direction of expression of genes (E1 gene, E2 gene, neomycin-kanamycin resistance marker gene neo ), and the shaded boxes represent transcriptional elements like promoters, poly- adenylation sites (pA), and bacterial origin.