DNA

http://www-personal.umich.edu/~sarhaus/courses/501w98/AUDRA/dna.jpg

What is DNA?• “DNA is a nucleic acid that contains the genetic

instructions used in the development and functioning of all known living organisms and some viruses.”

• “DNA is often compared to a set of blueprints or a recipe, or a code, since it contains the instructions needed to construct other components of cells, such as proteins and RNA molecules.”

http://en.wikipedia.org/wiki/DNA , http://www.ch.cam.ac.uk/magnus/molecules/nucleic/dna1.jpg

http://www.ec.gc.ca/EnviroZine/images/DNA.jpg , http://en.wikipedia.org/wiki/DNA

• “DNA consists of two long polymers of simple units called nucleotides with backbones made of sugars and phosphate groups joined by ester bonds.”

• “Attached to each sugar is one of four types of molecules called bases. It is the sequence of these four bases along the backbone that encodes information.”

What is DNA cont.?

DNA Base Pairing• DNA has 4 bases…

GuanineCytosine Adenine Thymine

•Certain Bases will only pair with one other base…

Guanine & Cytosine

Adenine & Thymine

http://www.biologycorner.com/resources/DNA-colored.gif

What is DNA Fingerprinting?• DNA Fingerprinting was developed in 1984, by a British geneticist named Alec Jeffrey's. Variation in peoples DNA was utilized to find individuals.

• “The chemical structure of everyone's DNA is the same. The only difference between people is the order of their base pairs.”

•“There are so many millions of base pairs in each person's DNA that every person has a different sequence.”

• “These patterns are able to determine whether two DNA samples are from the same person, related people, or non-related people.”

http://protist.biology.washington.edu/fingerprint/dnaintro.html http://www.umbi.umd.edu/education-outreach/scitech/dnaexplorationstudentpacket.pdf

Restriction Enzymes

http://www.umbi.umd.edu/education-outreach/scitech/dnaexplorationstudentpacket.pdf

• A tool scientists use to “digest or cut” DNA at a particular sequence.

•DNA restriction analysis is based on twoassumptions:

DNA molecules can be identified by a difference in the sequence of bases

Enzymes, produced naturally by bacteria, cut DNA molecules at specific sites identified by the difference in the sequence of bases.

Restriction Enzymes• In the example below, the DNA is cut with the enzyme, HaeIII. Note that the enzymecuts only at its particular recognition site (GGCC).

http://www.umbi.umd.edu/education-outreach/scitech/dnaexplorationstudentpacket.pdf

Questions?