DNA Deoxyribonucleic Acid DNA DNA the blueprint of
DNA (Deoxyribonucleic Acid)
DNA • DNA - the blueprint of life. • DNA contains the instructions for making proteins within the cell.
Why do we study DNA? DNA We study DNA for many reasons • its central importance to all life on Earth • medical benefits such as cures for diseases • better food crops
Chromosomes and DNA • Genes are places on chromosomes. • Chromosomes are made up of a chemical called DNA.
The Shape of the Molecule • DNA is a very long polymer. • The basic shape - a twisted ladder or zipper. – a double helix
The Double Helix Molecule • has two strands twisted together.
One Strand of DNA • One strand of DNA is a polymer of nucleotides • One strand of DNA has millions of nucleotides nucleotide
Nucleotides deoxyribose (sugar) bonded to a phosphate and nitrogenous base O O -P O Nitrogenous base O C C C O Phosphate C C O Deoxyribose
One Strand of DNA • The side of the ladder is phosphate and deoxyribose. • The steps are the bases. phosphate deoxyribose bases
Nitrogenous Bases • PURINES 1. Adenine (A) 2. Guanine (G) • PYRIMIDINES 3. Thymine (T) 4. Cytosine (C)
Important: • Adenine and Thymine always join together A T • Cytosine and Guanine always join together C G
DNA by the numbers • Each cell has about 2 m of DNA. • The average human has enough DNA to go from the earth to the sun more than 400 times.
Genetic Diversity… • Different arrangements of NUCLEOTIDES in DNA provides for DIVERSITY among living organisms.
The Code of Life… • The “code” of the chromosome is the SPECIFIC ORDER that bases occur. A T C G T A T G C G G…
- Slides: 14