1 / 17

Higher Biology

Higher Biology . Unit 1: 1.1 Structure of DNA. Learning Intention. To expand knowledge of the structure of DNA. Success Criteria. Name the components of a nucleotide and identify them in a diagram Describe how the sugar phosphate backbone is created

joie
Download Presentation

Higher Biology

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. Higher Biology Unit 1: 1.1 Structure of DNA

  2. Learning Intention • To expand knowledge of the structure of DNA

  3. Success Criteria • Name the components of a nucleotide and identify them in a diagram • Describe how the sugar phosphate backbone is created • Explain what is meant by a 3’ and 5’ end of DNA • Give the names of the 4 DNA bases • Name the type of bonds between the complementary bases

  4. From National 5… • On poster paper, in 3 minutes write/ draw as much as you can remember about DNA

  5. DNA • DNA stands for Deoxyribose Nucleic Acid. • It is as double stranded molecule made up of subunits called nucleotides. • Each nucleotide is made of 3 parts;- A base, a phosphate and a deoxyribose sugar (a sugar made of carbon, hydrogen and oxygen)

  6. Structure of a Nucleotide

  7. These are the same thing…

  8. Structure of a nucleotide The Carbons which make up the sugar are numbered in this arrangement. Remember Carbon 1 is at the base and work clockwise from there.

  9. This is what a nucleotide looks like at the molecular level…

  10. Arrangement of Nucleotides in DNA Nucleotides bond together to form the sugar-phosphate backbone of the DNA molecule. This is due to chemical bonds between the phosphateof one nucleotide and the carbon 3 of another nucleotide. The type of bonding involved in a Covalent bonds, which are very strong.

  11. Double stranded As DNA is double stranded, there is 2 chains of nucleotides. This is described as having two anti-parallel chainsdue to the arrangement of the nucleotides. 1 Side of the helix’ nucleotides have carbon 5 at the top, the other side of the helix has the carbon 5 at the bottom of the nucleotide.

  12. Essentially the nucleotide is flipped over on one side of the backbone.

  13. 3’ and 5’ • When we are discussing which Carbons are at the top of the nucleotide, we use the term “Prime”. • This is written as either 3’ or 5’. • 5’ is the strand which has the 5thCarbonat the top of the nucleotide • 3’ is the strand which has the 3rd Carbon at the top of the nucleotide. • So in a molecule of DNA, there is always a 5’ strand and a 3’ strand.

  14. The Code • There are 4 different types of base in DNA. • Thymine = T • Adenine = A • Guanine = G • Cytosine = C • They have complementarybase pairing • T pairs with A • G pairs with C

  15. Hydrogen Bonds • Holding the bases together are WEAK hydrogen bonds between the respective bases. Hydrogen bonds C and G 3 bonds T and A 2 bonds

  16. Success Criteria • Name the components of a nucleotide and identify them in a diagram • Describe how the sugar phosphate backbone is created • Explain what is meant by a 3’ and 5’ end of DNA • Give the names of the 4 DNA bases • Name the type of bonds between the complementary bases

More Related