DNA
DNA fingerprinting, DNA profiling, DNA typing
All terms applied to the discovery by Alec Jeffreys and colleagues at Leicester University, England
The DNA structure of certain genes are unique to each individual
Strands of genetic material with approximately 30,000 genes
Composed of repeating units of nucleotides
Nucleotides consist of a 5-carbon sugar, a phosphate group, and a nitrogen base Nitrogen bases are adenine (A),
thymine (T), cytosine (C), and guanine (G) Specifically pair A-T and C-GCalled complementary base-pairing
The sequences of base pairs grouped in threes (called codons)Codons code for a specific amino acid
Amino acids are joined to make a protein
Each protein has specific function
The process in which a DNA strand copies itself
1. Double helix is unraveled 2. Base pairs copy one strand of the
DNA while other nucleotides base pair with the other strand
3. Results in 2 identical copies of the DNA strand
The enzyme responsible for facilitating this process is DNA polymerase
Scientists can now use DNA polymerase to copy a DNA strand outside the living cell
Process is called PCR (Polymerase chain reaction) Which uses a DNA Thermal Cycler to double
the DNA and finally to multiply a million times
Useful for replicating small pieces of DNA found at a crime scene
Human Genome Project – determined the order of bases on all 23 pairs of chromosomes
Genetic code – the specific sequence of letter that specifies a protein
Restriction enzymes – certain chemicals that cut DNA into fragments that can be incorporated into another DNA strand
Recombined DNA is usually with the bacterial DNA
Bacterial DNA multiplies rapidly which produces new recombined DNAUses include: human growth hormone,
insulin production, crop production
1. Why is DNA important to forensic scientists?2. What are genes and what is their function?3. Describe the basic structure of the DNA molecule.4. Name the four bases associated with DNA. How
are these bases paired on the DNA molecule?5. What aspects of DNA define the role and function
of a DNA molecule?6. What is the human genome? Name two medical
applications of information about the human genome.
7. Briefly describe the process of DNA replication.8. What is PCR? Why is it useful to forensic scientists?9. What is recombinant DNA? How is recombinant
DNA technology used to treat diabetes?