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Chem of Life . Macromolecules: Nucleic Acids. Nucleic Acids. Biomolecules Store and Transmit Hereditary Information. Examples (Types) of Nucleic Acids. Deoxyribonucleic Acid (DNA) Ribonucleic Acid (RNA). DNA Functions. Provides directions for its own replication Direct RNA synthesis
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Chem of Life Macromolecules: Nucleic Acids
Nucleic Acids • Biomolecules • Store and Transmit Hereditary Information
Examples (Types) of Nucleic Acids • Deoxyribonucleic Acid (DNA) • Ribonucleic Acid (RNA)
DNA Functions • Provides directions for its own replication • Direct RNA synthesis • & through RNA controls protein synthesis
Genes • Consist of DNA (a nucleic acid polymer) • Molecules that enable living organisms to reproduce their complex components from one generation to the next.
DNA • Inherited from parents • Each chromosome contains one long DNA molecule with several hundred to more than a thousand genes) • Copied before cell division to be passed onto next generation.
Molecular Structure: • Monomer: nucleotide • Each nucleotide monomer consists of: • A phosphate group • Pentose sugar • Nitrogenous base
RNA Structure • Polynucleotide: • Pentose Sugar = Ribose • Nitrogenous base (a purine or a pyrimidine) • Phosphate group • Simple polynucleotide (single strand)
DNA Structure • Polynucleotide: • Pentose Sugar = deoxyribose • Nitrogenous base (a purine or a pyrimidine) • Phosphate group • Double Stranded
Ribose vs. Deoxyribose • Deoxyribose lacks an Oxygen atom on the second C in the ring
FYI • Numbered Carbons have a prime (‘) after them, note the 5’ C end is the one that sticks out from the ring. • The phosphate group attached to the 5’ C of the ring
Recap • Nucleic Acid Polymer = polynucleotides • Examples: DNA & RNA • Nucleic Acid Monomer = nucleotide • Nucleoside (nitrogenous base & pentose) • Phosphate group
Nitrogenous Bases • Two families: • Pyrimidine • Purine
Pyrimidine: • 6-membered ring & N atoms • N atoms take up the H+ from solution (base) • Members include: • Cytosine (C) • Thymine (T) • (found only in DNA) • Uracil (U) • (found only in RNA)
Purines • Larger 6-membered ring fused to a 5-membered ring • Members include: • Adenine (A) • Guanine (G)
Nitrogenous BaseFunctional Groups • Vary • Attached to the rings (Handout)
Polymerization • Adjacent nucleotides are joined by covalent bonds (phosphodiester linkages) • Involves the –OH group on 3’ C of one nucleotide to the phosphate group on the 5’ C of another nucleotide
Polymerization • Result = backbone with repeating sugar-phosphate with a distinct 3’ and 5’ ends • DNA (The 2 sugar phosphate strands run in opposite directions = antiparallel) • The nitrogenous bases stick out like appendages and are complementary in DNA.
Biological Staining: • Acridine orange (AO) is a nucleic acid selective fluorescent cationic dye useful for cell cycle determination. It is cell-permeable, and interacts with DNA and RNA by intercalation or electrostatic attractions. When bound to DNA, it is very similar spectrally to fluorescein. Like fluorescein, it is also useful as a non-specific stain for backlighting conventionally stained cells on the surface of a solid sample of tissue (fluorescence backlighted staining[4]). Wells J. (1988) A Technique for Staining the Superficial Cells of Plucked Hair Follicles and Other Solid Tissues, Stain Technology, Vol 63, No3.
Resources: • http://www.millerandlevine.com/chapter/12/bases.html • http://www.biologycorner.com/bio1/DNA.html • 2006 Miller & Levine Prentice Hall Biology • 2005 Campbell & Reece Biology 7thed