Nucleic Acids
Informational macromolecules Polymers that store, transmit, and express heredity information Information is encoded in the sequence of monomers.
Two types of Nucleic Acids DNA Deoxyribonucleic acid Stores and transmits genetic information RNA Ribonucleic acid Takes info from DNA to ribosomes that specifies amino acid sequence in proteins
Nucleic acids and the proteins encoded for by them determine the metabolic functions of an organism. DNA proteins
Nucleotides Monomers that make up nucleic acids Consists of: Nitrogen-containing base Pentose sugar Deoxyribose ribose 1-3 phosphate groups
Nitrogen base Phosphate Group Ribose Sugar
Nitrogen bases Pyrimidine Purines Cytosine Thymine Uracil (only in RNA) Purines Adenine Guanine
Formation of nucleic acids New nucleotides are added to the existing chain one at a time. Pentose sugar of the last nucleotide and the phosphate of a new nucleotide undergo a condensation reaction forming a phosphodiester bond. Attached to 5’ carbon of sugar and bonds to 3’ of existing sugar. Nucleic acids are said to grow in the 5’ to 3’ direction.
Base paring DNA RNA Adenine Thymine Cytosine Guanine Adenine Uracil
Base paring DNA RNA Less flexible Lack of hydroxyl group at the 2’ position of the deoxyribose. Composed of two polynucleotide strands RNA More flexible Usually single-stranded Long RNA can fold itself forming a variety of structures.
Base paring Held together primarily by hydrogen bonds. Hydrogen bonds form between partial negative charge on a hydrogen atom. Complementary base pairing Arrangements of polar bond in the nucleotide bases favor the pairing of bases. Hydrogen bonds are stronger because there are so many in DNA & RNA. Not as strong as covalent bonds Breaking and making hydrogen bonds in nucleic acids is a vital role in living systems.