1 / 23

DNA Structure

DNA Structure. DNA Structure. DNA consists of two molecules that are arranged into a ladder-like structure called a Double Helix . A molecule of DNA is made up of millions of tiny subunits called Nucleotides . Each nucleotide consists of: Phosphate group Pentose sugar Nitrogenous base.

lerato
Download Presentation

DNA Structure

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

  2. DNA Structure • DNA consists of two molecules that are arranged into a ladder-like structure called a Double Helix. • A molecule of DNA is made up of millions of tiny subunits called Nucleotides. • Each nucleotide consists of: • Phosphate group • Pentose sugar • Nitrogenous base

  3. Nucleotides Phosphate Nitrogenous Base Pentose Sugar

  4. Nucleotides • The phosphate and sugar form the backbone of the DNA molecule, whereas the bases form the “rungs”. • There are four types of nitrogenous bases.

  5. Nucleotides A T C Adenine Thymine G Guanine Cytosine

  6. Nucleotides • Each base will only bond with one other specific base. • Adenine (A) • Thymine (T) • Cytosine (C) • Guanine (G) Form a base pair. Form a base pair.

  7. DNA Structure

  8. DNA Structure • Because of this complementary base pairing, the order of the bases in one strand determines the order of the bases in the other strand.

  9. A A A A T T T T C C C G G G

  10. DNA Structure • To crack the genetic code found in DNA we need to look at the sequence of bases. • The bases are arranged in triplets called codons. A G G - C T C - A A G - T C C - T A G T C C - G A G - T T C - A G G - A T C

  11. DNA Structure • A gene is a section of DNA that codes for a protein. • Each unique gene has a unique sequence of bases. • This unique sequence of bases will code for the production of a unique protein. • It is these proteins and combination of proteins that give us a unique phenotype.

  12. DNA Replication • DNA replication is the process of copying a double-stranded DNA molecule. • Produces two copies of DNA that each contain one of the parent strands and one entirely new strand.

  13. DNA Replication

  14. DNA Replication • An enzyme called Helicase “unzips” the base pairs by breaking the bonds.

  15. A A A A T T T T C C C G G G Helicase

  16. DNA Replication • An enzyme called Helicase “unzips” the base pairs by breaking the bonds. • Raw materials are needed to “re-build” the two parent strands.

  17. A A A A T T T T C C C G G G

  18. DNA Replication • An enzyme called Helicase “unzips” the base pairs by breaking the bonds. • Raw materials are needed to “re-build” the two parent strands. • Another enzyme called DNA Polymerase is used to arrange nucleotides in a new complimentary strand.

  19. A A A A A A T T T T T T C C C C G G G G G DNA Polymerase

  20. DNA Replication • The result is two identical copies of DNA, each with an original parent strand and a new strand.

  21. A A A A T T T T C C C G G G

  22. A A A A A A A A T T T T T T T T C C C C C C G G G G G G

More Related