Question

Describe how restriction enzymes and ligase enzymes are used to make the plasmids that are introduced to bacteria cells during transformation. Include the words sticky ends and complementary in your response.

Answer 1

Answer:

DNA restriction enzymes cut the DNA molecule, while DNA ligases join the resulting DNA fragments

Explanation:

Transformation is a naturally occurring process by which bacteria incorporate exogenous genetic material from their surrounding environment. This process (transformation) is used for DNA cloning via plasmid vectors. In DNA cloning, transformation occurs after restriction enzymes cut the DNA at specific sequences named palindromic sequences (i.e, sequences that can be read the same in opposite direction). Restriction enzymes can generate sticky-ends, where enzymes make staggered cuts in the two strands (e.g., BamH), or blunt ends, where the resulting strands are of the same length (e.g., HaeIII). In general, sticky-end enzymes are more useful because they generate a 3' overhang in one molecule and a complementary 5' overhang in the other, increasing the yield and specificity of ligation. During ligation, a DNA ligase is used to join both DNA strands by forming phosphodiester bonds in the plasmid. Following transformation, bacteria can be selected on antibiotic plates.