Nucleic Acids. By Sarah, Zach, Joanne, and Dean

Transcription

1 Nucleic Acids By Sarah, Zach, Joanne, and Dean

2 Basic Functions Carry genetic information (DNA storing it) Protein synthesis Helps in cell division (DNA replicates itself) RNA- numerous functions during gene expression (carrying instructions from DNA to ribosomes)

3 Monomers Known as nucleotides Have three parts: a nitrogenous base, a five carbon sugar, and one or more phosphate groups Nitrogenous Bases Two families Purines- larger than pyrimidines, made of a six membered ring that is fused to a five membered ring. Include Adenine (A) and Guanine (G). A, G, and C are all in RNA and DNA, but T is only in DNA, while U is only in RNA Pyrimidines- made up of one six member ring of carbon and nitrogen atoms. Include Cytosine (C), Thymine (T), and Uracil (U).

4 Monomers Five Carbon Sugars The sugar in RNA is ribose, while the sugar in DNA is deoxyribose (one less oxygen atom than in ribose) Each of the five sugar carbons on the sugar are distinguished from the ring atoms on the nitrogenous base by using a prime (') The portion of a nucleotide without a phosphate group is known as a nucleoside Phosphate Group Forms a bond with the 5' carbon of the sugar, completing the nucleotide

5 Bonds Between Monomers Phosphodiester linkage- phosphate group links the 3' carbon to the 5' carbon of the next monomer. Hydrogen Bonds- bind the nitrogenous bases of one strand of DNA to the other. (as well as RNA)

6 Polymer The phosphate groups form phosphodiester linkages with the two surrounding sugars Results in a sugar-phosphate backbone (the nitrogenous bases are not part of the backbone) The two ends of the polymer are different; one side ends with a phosphate group connected to a 5' carbon, while the other ends with a hydroxyl group attached to a 3' carbon Sequence of bases determine the meaning of each gene (5'-AAACTTGAA-3' means something different from a gene that has a sequence of 5'-GGATGCCTG-3')

7 Structure DNA RNA 2 strands double helix antiparallel: back bones run in opposite directions from 5' to 3'opposite directions sugar-phosphate backbone (outside) + nitrogenous bases (interior) A, T, G, C adenine always pairing with thymine and guanine always pairing with cytosine the 2 strands are complementary- each is the predictable counterpart of the other 1 strand shape = variable depending on type (mrna, trna, rrna) A, U, C, G adenine always pairs with uracil and guanine always pairing with cytosine complementary base pairing also occurs (b/w parts of 2 RNA molecules or 2 stretches of nucleotides in same RNA molecule)

8 Real Life Examples of Nucleic Acids in Action: Human body DNA carries genetic information in form of genes: individual unit of inheritance recording the genetic background of the individual The sequences of nucleotides in DNA molecules are passed down from parents to children why children have similar traits to their parents DNA and RNA help with protein synthesis Mutations can create mild to extreme diseases in organisms ex: Down Syndrome, color blindness

9 Real Life Examples of Nucleic Acids in Action Evolution Studies Comparing different species DNA can show relatedness among species depending on if the nucleotide sequences are similar or different Viruses consist of a single or double stranded nucleic acid and at least one protein the nucleic acid carries the virus s collection of genes classified as either DNA viruses or RNA viruses the viruses go into host cells to change the cell s metabolic machinery into the production of new viruses, and so forth can multiply in living cells of animals, plants, humans, and bacteria ( Virus )... see sources page

10 Sources "Virus." University of Oregon, n.d. Web. 19 Sept