Can someone explain Why? I never learn like what banding patterns are please tha
ID: 302848 • Letter: C
Question
Can someone explain Why? I never learn like what banding patterns are please thank
We a Welcome to ASSIST LAB COAT N WITH ANSWERS SHOWN IN BOLD AND BLUE These problems are centered around restriction digests, restriction mapping, and the interpretation of band patterns in gels. Problems of this type will almost certainly be on the final exam. 1. (3 part short answer) The figure to the left shows a 5 kb plasmid molecule containing a single cleavage site for the BamHI (B) restriction endonuclease, and two EcoRi (E) cleavage sites. a. If the plasmid is cleaved with BamHl, how many fragments will there be? 1 b. If the plasmid is cleaved with EcoRI, how many fragments will there be? 2 c. If the plasmid is cleaved with BamHl EcoRI, how many fragments will there be? 3 The figure to the left shows a 10 kb plasmid molecule containing a single cleavage site for the EcoRI (E) restrictionExplanation / Answer
BamHI and EcoRI are restriction endonuclease enzymes (RE). RE are produced in bacterias when they are infected with a virus. As you might be aware that viruses are nothing but covered nucleic acids (DNA and RNA), the bacterias produce REs to destroy the invading virus' genome.
REs cut the genome of the virus and render it inefficient to do any damage by cutting at specific sites (Recognition Site)
in their genome which a particular RE recognises.
A particular restriction enzyme will always recognise that specific nucleotide sequence on any length of DNA (whatever might be the source) and act on it.
In short, RE is an enzyme that cut DNA at a particular site.
For example, the recognition site for EcoRI is GAATTC.
Let a random length of DNA be 5' ATGCCGTAGAATTCTT 3'
The enzyme will recognise the sequence and cut the DNA length between G and A of GAATTC.
These Restriction endonuclease enzymes are now being used in genetic engineering on many levels.
One such use is providing a working gene to a host by delivering this gene of interest inside the host through a vector. The inserted gene is treated as a part of the host genome and expressed as a product in the host.
Plasmids are one such vector which delivers the gene of interest.
The plasmid presented has recognition sites for Restriction Endonuclease BamHI and EcoRI denoted as B and E respectively. (B and E are actually a sequence of nucleotides as explained above)
It means it will be cut by these two enzymes.
Now (a) If we use only BamHI, It will be cut at site B. The site B is a sequence of bases hence B will split into B' AND B''
The resultant fragment will be B'.........E.........E.............B''
(b) Similarly, If we use EcoRI, it will be cut at the two E sites (Say E1 and E2)
the resultant fragment will be
E1' ........B........... E2' and
E1''..........E2''
(c) If both BamHI and EcoRI is used, the fragments will be
B'............E1'
E1''.........E2''
E2' ..........B''