bio 2-18-08 - Bio 2/18/08 Studying how gene functions or to...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Bio 2/18/08 Studying how gene functions or to learn its sequence often requries: 1. single gene away from other genes in the genome - restriction enzymes: cut DNA into specific sequences 2. methods to produce large quantity of the gene so that its function can be observed easily - particular bacterium Restriction enzymes - Specific enzymes in bacteria that cut foreign DNA for defense - After being restricted the foreign DNA can be digested by exonucleases, enzymes that digest DNA from ends, one base at a time - In contrast, restriction enzymes are also called endonucleases Restriction enzyme mechanism - Restriction enzymes recognize specific sequences (restriction sites) of DNA and cut both strands in specific ways - The sequences recognized are 4-8 base pairs - Are palindromes - Average frequency of restriction sites is ¼ 4 (1/256) to 1/4 8 (1/65536) - Restriction reaction creates reproducible DNA segments called restriction fragments Restriction enzyme structure - Most are homodimers, made up of two subunits; in this case they are identical
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 2

bio 2-18-08 - Bio 2/18/08 Studying how gene functions or to...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online