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?