DNA Structure Forensics Chp 12 DNA Analysis DNA

DNA Structure Forensics Chp. 12 DNA Analysis

DNA Structure n A gene is a long section of a DNA molecule whose sequence of building blocks specifies the sequence of amino acids in a particular protein. n Protein- fundamental component of living cells n Enzymes §Hemoglobin n Hormones §Insulin n Antibodies

How does DNA work n DNA (nucleic acid) n Amino Acids n Protein Do a job (perform a function) n Analogy to remember what’s going on, build a house n DNA is the blue prints (instructions) n Amino Acids are the lumber n Proteins are the house…

DNA Structure n View from the side - Helix n Partially unwound double helix so you can see components

Views from the top Model X-Ray Photo-51

n DNA composed of nucleotides n Sugar (deoxyribose) n Phosphate group n Nitrogenous bases A-T n. C-G n

DNA Structure n A 5 C sugar and a phosphate group form the backbone

DNA Structure n Nitrogenous bases n. A, T, C, & G nmake up the rungs on the ladder

Complimentary Base Pairing n Bases held together with Hydrogen bonds n Guanine pairs with Cytosine n Triple bond n Adenine pairs with Thymine n Double bond

DNA Structure 3 D Video Clip (Click next 4 times)

3 methods to analyze DNA n RFLP- Restriction Fragment Lengths Polymorphism n Restriction enzymes cut DNA up n Not best method because we need a lot of DNA n PCR – Polymerase Chain Reaction n Polymerase – enzyme that replicates (makes more) DNA n STR – Short Tandem Repeats n Specific sequences of DNA fragments that are repeated at a particular site on a chromosome

Replication Technology n Mitochondrial DNA- from mom only n n good for hair, teeth, and bone PCRn Perhaps the most successful technology to ever emerge from LIFE SCIENCE!!! n Many Uses n Forensicsn blood, convict, exonerate false accusations n Agriculture, Vet. , Medicine, Env. Sci. , n Microorganisms, viruses, parasites…