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Nucleic Acids. Nucleic acids. Ribo -nucleic acid (RNA) Deoxyribonucleic Acid (D NA) They are polymers made up of repeating monomer units called nucleotides DNA is double stranded helix , RNA is single C-H-O-N-P atoms. 21. Nucleic acids store and transmit hereditary information.
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Nucleic acids • Ribo-nucleic acid (RNA) • Deoxyribonucleic Acid (DNA) • They are polymers made up of repeating monomer units called nucleotides • DNA is double stranded helix, RNA is single • C-H-O-N-P atoms 21
Nucleic acids store and transmit hereditary information • Information flows from DNA RNA Proteins
Phosphate base Stay the same sugar Changes Contains nitrogen & carbon Pentose sugar (5 Carbon atoms) Nucleotide Structure 3 components: • Pentose sugar (ribose in DNA) • Phosphoric acid • Organic base (always contains nitrogen)
Nucleotide 3 components: Pentose sugar; deoxyribose Phosphate group Nitrogenous base; 4 types: Join by condensation phosphate base Stay the same sugar Changes Contains nitrogen & carbon Ribose sugar in RNA Deoxyribose sugar in DNA Pentose sugar (5 Carbon atoms)
5Bases • Purines – • Double ringed structure • Pyrimidines – • Single ringed structure
Nucleic acids are polymers of nucleotides (polynucleotides) joined by phosphodiester bonds (phosphate to sugar)
Bondings • The base and sugar join with a: glycosidic bond • The phosphate and sugar join with an: ester bond Both require a condensation reaction to occur
Phosphate 2 condensation reactions occur in the formation of a nucleotide: H Ester bond OH Glycosidic bond OH H Base Sugar
DNA • Genetic material inherited from parents • Extremely long: hundreds-thousands of genes • Contains the information that programs cellular activities • DNA is “read” by proteins and translated into proteins. • Double stranded helix • Has the ability to copy itself
Complementary Base Pairing *Purines always pair with pyrimidines* A joins to T (2 hydrogen bonds) C joins to G (3 hydrogen bonds) see
5’ 3 hydrogen bonds 3’ C G 0.34nm A T 3’ 2 hydrogen bonds 5’ 2nm
RNA • Messenger RNA (mRNA) conveys the DNA code out of the nucleus to the cytoplasm (ribosome) • Single stranded • Multiple complex structures • A,U,G,C
RNA can adopt complex 3-D structures and is not restricted to the double helix structure RNA carries information from DNA (nucleus) to the ribosome via reverse transcription, followed by translation.
Molecular Clocks • Linear sequences of nucleotides in DNA are passed from parent to offspring. DNA determines the amino acid sequence of proteins • Siblings have DNA that is more alike than an unrelated person • 2 species should have similar DNA if they are closely related based on fossil and anatomical evidence • The more differences in the DNA codes, the longer the time the two species have evolved separately.