Question

Select the true statement or statements. Restriction enzymes break a phosphodiester bond on only one of the two DNA strands. Restriction enzymes break a phosphodiester bond on both of the DNA strands. All restriction enzymes produce a region of single-stranded DNA. Two different linear DNA molecules are cut with a single restriction enzyme such that only one end of each molecule is cut and these ends have regions of single stranded DNA. The two different DNA molecules will have compatible ends. Two different linear DNA molecules are each cut with a different restriction enzyme such that only one end of each molecule is cut and these ends have regions of single stranded DNA. The two different DNA molecules will NOT have compatible ends.

Answer 1

Answer:

- Restriction enzymes break a phosphodiester bond on both of the DNA strands.

- Two different linear DNA molecules are cut with a single restriction enzyme such that only one end of each molecule is cut and these ends have regions of single stranded DNA. The two different DNA molecules will have compatible ends.

Explanation:

Restriction enzymes are a type of enzyme that recognizes target DNA sequences and cuts them at these specific sites. These enzymes catalyze the hydrolysis of phosphodiester bonds by cleaving double-stranded DNA (dsDNA) sequences at specific sites on both DNA strands. There are restriction enzymes that generate sticky ends (cohesive ends), i.e., small stretches of single-stranded DNA (ssDNA) that self-ligate or ligate with a complementary region from another DNA molecule. Restriction enzymes that generate sticky ends are very useful in molecular cloning and DNA recombination techniques because they can hold two pieces of DNA together so that DNA ligase can covalently link them.