Question

Which of the following statements regarding restriction enzymes is NOT true? See Section 15.1 (Page 554) . Which of the following statements regarding restriction enzymes is NOT true? See Section 15.1 (Page 554) . Most restriction enzymes recognize sequences of 20-25 bp in length. Bacteria can add methyl groups to their DNA to prevent digestion by endogenous restriction enzymes. Most restriction enzymes recognize palindromic sequences in host DNA. Restriction enzymes may produce either sticky or blunt ends when digesting host DNA.

Answer 1

Answer:

Most restriction enzymes recognize sequences of 20-25 bp in length

Explanation:

Sequences of DNA that are recognized by restriction enzymes are called recognition (or restriction) sites are usually are between 4 and 8 bases long. Many of them are palindromic, which means that they are the same when you read it backwards and forwards (mirror-like).

Restriction enzymes are endonucleases, which means they cut phosphodiiester bonds within DNA. These enzymes are from prokaryotic organisms (archea and bacteria) which use them as defending mechanism against viruses. Prokaryotes protect their own DNA via methylation, performed by methyltransferase.