Using EcoRI, which cuts at 5' GAATTC 3', indicate how many strands would be produced?

Question

5’ A G A A T T C G C T T A A G T C G A C G T A A G C C G G A A T T C C A T T C G A A T T A G 3’ 3’ T C T T A A G C G A A T T C A G C T G C A T T C G G C C T T A A G G T A A G C T T A A T C 5’

1. Using EcoRI, which cuts at 5' GAATTC 3', indicate how many strands would be produced?
2. If instead you used HindIII, which cuts at 5'AAGCTT3', indicate how many strands would be produced.

I'VE BEEN WORKING VERY HARD ON THEESE AND I CANT GET IT

Answer 1

EcoRI is a restriction endonuclease, that will cut the DNA at the palindromic sequence 5'GAATTC3' as stated. What this means, is that the enzyme will cleave the DNA into separate pieces whenever it recognizes 5'->3' GAATTC. When reading 5' -> 3', we spot two GAATTC stretches that by necessity have palindromic repeats in the 3' -> 5' direction CTTAAG, which means two cuts will be made, one at each site, separating the DNA strand into 3 separate strands. One before this first GAATTC, one after it but before the second, and the last one after the second GAATTC.

HindIII instead cuts at 5'AAGCTT3' or in the other direction 3'TTCGAA5'. Surprisingly, this sequence is not found anywhere in the provided stretch of bases, meaning no cuts will be made and there will still be one strand of DNA.