01b dna structure

892 views

Published on

Published in: Technology, Education
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
892
On SlideShare
0
From Embeds
0
Number of Embeds
7
Actions
Shares
0
Downloads
0
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

01b dna structure

  1. 1. DNA Deoxyribonucleic Acid
  2. 2. Components of DNA <ul><li>Nucleotide </li></ul><ul><li>Phosphate Group </li></ul><ul><li>Deoxyribose Sugar </li></ul><ul><li>Nitrogen Base </li></ul>
  3. 3. Nitrogen Bases <ul><li>There are FOUR nitrogen bases </li></ul><ul><li>Adenine, Thymine, Guanine and Cytosine </li></ul><ul><li>Complementary Base Pairs </li></ul><ul><li>A=T (two hydrogen bonds) </li></ul><ul><li>G=C (three hydrogen bonds) </li></ul>
  4. 4. Complementary Base Pairs
  5. 5. Pyrimidine vs. Purine
  6. 6. DNA <ul><li>If you were to stretch the DNA of one cell it would be 6 feet long. </li></ul><ul><li>All of your DNA would reach the moon! </li></ul><ul><li>DNA has a special mechanism of getting all that DNA into the cell </li></ul><ul><li>It is called supercoiling. </li></ul><ul><li>TRY THE ACTIVITY!!! (If time permits) </li></ul>
  7. 7. DNA Organization
  8. 8. DNA Organization <ul><li>chromatin – DNA strands populated with proteins; found in eukaryotes (humans) </li></ul><ul><li>-prokaryotic DNA is commonly referred to as being “naked” (bacteria) </li></ul><ul><li>histones – proteins that bind to eukaryotic DNA </li></ul><ul><ul><li>DNA backbone has a negative charge (phosphate group) </li></ul></ul><ul><ul><li>histones bind to DNA due to a positive charge </li></ul></ul>
  9. 9. Histones <ul><li>approximately every ~200 bp of DNA is associated with a group of histones </li></ul>200 bp 8 histones single histone DNA strand nucleosome
  10. 10. Solenoid Fibre <ul><li>nucleosomes are organized in a stacked spiral structure </li></ul><ul><li>the solenoid fibre is known as the 30 nm fibre </li></ul>
  11. 11. DNA Supercoiling <ul><li>supercoiling – twisting and compacting to form mitotic chromosomes </li></ul>

×