Nucleic acids

Nucleic acids

1. Genetic information

   • DNA contains genetic information that codes for growth and development. They are coiled up so they can fit into a small space. Contains genes that code for a specific protein.

2. Structure

   • Made up of many nucleotides.
   • Made from a deoxyribose sugar, a phosphate and a nitrogenous base.
   • A-T (purine), C-G pyrimidines)

3. Double helix

   • Nucleotides join together to form a poly nucleotides
   • The sugar and the phosphate join to make a sugarphosphate backbone
   • Two DNA polynucleotides join together anti parallel by forming hydrogen bonds between them. 2 H-bonds between A-T, 3 H-bonds between C-G.

4. RNA

   • Protein synthesis
     • DNA carries the intructions to make proteins as genes. The organelles that make proteins are in the cytoplasm. DNA is too big to pass through the nuclear pores. DNA copies into RNA. RNA leaves the nucleus and joins to a ribosome where it can synthesis a protein.
   • Has a ribose sugar, single polynucleotide strand, and uracil instead of thymine. A-U.

5. Self replication

   • Hydrogen bonds between the two polynucleotides break. The helix unzips itself to form two single strands. Each strands acts as a template. Free floating DNA joins the exposed bases by complementary base pairing. The nucleotides are joined together by the enzyme polymerase. Hydrogen bonds form between the bases on the original and new strand. Each new DNA molecule contains one strand from the original and one new one. Called semi conservative replication

6. Genes

   • A sequence of DNA nucleotides that codes for a protein. They determine the order of the amino acids. Each amino acid is coded from three bases in a gene