DNA and RNA are nucleic acids that are made up of nucleotides containing a phosphate group, a 5-carbon sugar (ribose in RNA and deoxyribose in DNA), and a nitrogenous base. DNA exists as a double helix containing two anti-parallel strands bound together via hydrogen bonding between complementary nucleotide base pairs of adenine-thymine and cytosine-guanine. RNA is single-stranded and contains the base uracil instead of thymine. DNA stores genetic information in the nucleus, mitochondria, and chloroplasts, while RNA aids in protein synthesis and has various functions in the nucleus and cytoplasm.

1. Topics 3.3 & 7.1Nucleic AcidsIB Biology

2. Where can you find it?Inside the cell- nucleus, chloroplasts and mitochondriaChromosomes are made of DNA

3. Nucleic AcidsPolymers: DNA (deoxyribonucleic acid) RNA (ribonucleic acid)Units: nucleotidesNucleotide: sugar + nitrogenous base + phosphate

4. Parts of a NucleotidePhosphateSugar: Ribose or Deoxyribose (both pentoses)Nitrogenous Bases: - Purines (double rings): Adenine + Guanine - Pyrimidines (single ring): Cytosine, Thymine, Uracil (RNA only)

5. Structure of DNADiscovery of Double Helix: 1962

6. James Watson, Francis Crick and Maurice Wilkins received a NOBEL PRIZE

7. Watson, Crick and Wilkins used unpublished data from Rosalind Franklin’s research obtained without her knowledge and used without her consent. - She was misrepresented and unrecognized - She died of cancer in 1958We know now: DNA is a double helix made of... - 4 nucleotides - A, T, G, C - in 2 polynucleotide strands - strands run antiparallel - [5'-----3'] - held together via weak H-Bonds & complimentary base pairing (A-T and C-G)

8. DNA is double-stranded, withcomplementary base pairing

9. Observe - hydrogen bonds- complementary base pairing :A – TC – G - covalent bonds between 2 nucleotides (formed through condensation)

10. Counting Carbons...Anti-parallel strandsOne side 5’  3’Other side 3’  5’

11. DNA StructureIn eukaryotes it is always associated with proteinsNUCLEOSOMES = DNA wrapped around 8 histones (proteins)Help compact DNA Help control DNA transcription

12. Single copy x Highly repetitive sequencesMuch of DNA in eukaryotes = repetitive base sequences, which are not translated (satellite DNA) = 5-300 bases / repeated as many as 10,000x5-45% of DNA = function not clearSingle copy/unique genes = actually code for something (small proportion)

13. DNA’s jobStores informationIt has the code for all 20 amino acidsMutation: changes in the base sequence  primary structure of a protein is altered (changing its shape)Can be harmful, neutral or beneficial Important: create variation – basis of natural selection

14. RNADiscovered after DNASingle strand shorter than DNAContains Uracil instead of ThymineSugar = ribose (DNA contains deoxyribose)DNA: nucleus, mitochondria, chloroplastsRNA: nucleus, cytoplasm, part of ribosomesTypes:RNAm: messenger blueprint for protein

15. RNAr: ribosomal  makes up ribosomes

16. RNAt: transfer  delivers the proper amino acid to the ribosome