1 / 19

DNA Structure & Function

DNA Structure & Function. You Tube Index. DNA Structure (in order of usefulness) DNA Structure http://glencoe.mcgraw-hill.com/sites/9834092339/student_view0/chapter14/dna_structure.html Good (factual, but dry) http://www.youtube.com/watch?v=tknYrU98rBk&feature=fvwrel

danno
Télécharger la présentation

DNA Structure & Function

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DNA Structure & Function

  2. You Tube Index DNA Structure (in order of usefulness) • DNA Structure • http://glencoe.mcgraw-hill.com/sites/9834092339/student_view0/chapter14/dna_structure.html • Good (factual, but dry) • http://www.youtube.com/watch?v=tknYrU98rBk&feature=fvwrel • Structure & Prot synthesis • http://www.youtube.com/watch?v=FUA6_Ucw3i4 For history of discovery of DNA and structure see the Powerpoint “DNA History”

  3. Watson & Crick (credited with discovery of STRUCTURE of DNA, though their work relied heavily on the work of others)

  4. !!! DNA Functions • Carries genetic code for life processes • Can replicate to continue life… • Lengths of DNA (genes) code for production of proteins that are • structural • functional • & are 95% of human body!

  5. !!! DNA Packaging

  6. Role of DNA Terms(over the course of this AS & others you will understand all of these terms) • Genome – all the DNA in a cell • Genes – sections of DNA coding for the production of proteins • Chromosomes - • Chromatid • Nucleus - • Nuclear Membrane • Chromatin • DNA • Nucleotides - the repeating unit of DNA • Protein • mRNA • Prokaryote – cells / organisms without a nucleus • Eukaryote – cells / organisms with a nucleus • Protein synthesis – process where protein is manufactured • Mitochondria – organelle (“little organ”) in a cell where energy (ATP) is produced • Cytoplasm • Enzymes • Metabolism • Cell division • Centromere

  7. !!! Nucleic Acids • Two types: • DNA – Deoxyribose nucleic acid (location: nucleus) • RNA – Ribose nucleic acid (location: nucleus + cytoplasm) • Made of repeating units: nucleotides • Nucleotide made of: • Nitrogen base • A 5-carbon sugar (deoxyribose in DNA, ribose in RNA) • Phosphate group

  8. Sweet Difference

  9. !!! DNA Structure • The two strands are “anti parallel” • One strand runs from 3’ to 5’ the other 5’ to 3’

  10. DNA Structure • Shape: double helix (like a twisted ladder)

  11. !!! DNA Structure In RNA the base U (Uracil) replaces thymine • 4 bases: • A – Adenine T – Thymine • G – Guanine C – Cytosine • “Rungs” - Bases held together by hydrogen bonds • A pairs with T (two bonds) • G pairs with C (three bonds) • “Backbone” • Sugars joined to phosphates * by “phosphodiester” bonds! • Complementary vs template • Since you find a C opposite a G… etc the second strand is said to be complementary to the first. • And: the first strand can be used as a template to make a new complementary strand

  12. * Pyrimidines vs Purines • The “pyrimidine bases” are: • C & T (one ring structure) • The “purines” are: • A & G (double ring structure) To remember: purines = two rings

  13. Length of DNA in organisms • Only 4 bases BUT one DNA molecule = millions of bases long • Human: 6 billion base pairs • Bacteria: ~ 4.3 million bases • Viruses…..

  14. ΦX174 Bacteriophage DNA Sequence Bacteriophage = virus affecting bacteria 9 genes, each codes for one protein. Genes overlap, one genes is highlighted. Human genome = 1 million times longer

  15. How much DNA in humans? • ~ 100,000,000,000,000 cells in the human body • 2m of DNA in each cell (3-5cm per chromosome) • DNA length in kilometres: • 200,000,000,000 km • How many times to the moon? (moon = 184,000km) • 1,086,957 times • How many times to the sun & back? (= 300,000,000km) • 667 times

  16. DNA Structure END

More Related