Describe the structure of DNA and explain how it allows DNA to be used in solving crimes, paternity testing, identifying tendencies for diseases, treating or curing genetic diseases, stem cell research, curing viral diseases, curing cancer, replacing body parts, changing human characteristics.
Structure of DNA:
The DNA molecule is comprised of two long polynucleotide chains which are made up of four different kinds of what are referred to as nucleotide subunits. Each chain is referred to as a DNA chain or strand. Hydrogen bonds hold together bases of the nucleotide, or bond the base pairs. These pairs, bonded together, make up the entire chain, or double helix, known as a DNA molecule.
Nucleotides are comprised of a five carbon sugar ( deoxyribose ) and attached are one or more phosphate groups and a nitrogenous base ( Adenine, Guanine, Thymine, or Cytosine ). These nucleotides are covalently bonded ( bonds where atoms share electrons ) in the chain through the sugars and phosphates and form the backbone of the DNA strands. The bases are abbreviated as A T G C, and A always pairs with T and G always pairs with C in the chains. The way these nucleotides are linked via their subunits is what gives a DNA strand chemical polarity, and polarity is indicated by labelling each end of the chain as 3' and the opposite end as 5'. The second DNA strand is labelled 5' and 3'. The bonding allows the formation of the well known double helix structure. This is referred to as anti-parallel since the 3' ends pair with each corresponding 5' ends on the two strands. ...
The expert examines DNA testing to settle disputes.