1 / 14

DNA ( D eoxyribo n ucleic A cid)

DNA ( D eoxyribo n ucleic A cid). The Code of Life. Objectives. Explain the principal function of DNA Describe the structure of DNA Define the term, “complementary base pairing” Explain the role of complementary base pairing in the replication of DNA

mirari
Download Presentation

DNA ( D eoxyribo n ucleic A cid)

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 (Deoxyribonucleic Acid) The Code of Life

  2. Objectives • Explain the principal function of DNA • Describe the structure of DNA • Define the term, “complementary base pairing” • Explain the role of complementary base pairing in the replication of DNA • Summarize the main features of DNA replication

  3. Function • DNA works like a code • DNA stores and transmits genetic information • This information tells cells which proteins to make and when to make them • Proteins are needed for cell structure • Proteins help control chemical processes within cells

  4. Holt, Modern Biology DNA Structure: Double-Helix http://www3.interscience.wiley.com:8100/legacy/college/boyer/0471661791/structure/dna/dna.htm • A molecule of DNA consists of two chains, strands composed of nucleotides, linked together to form a chain. • These chains are arranged like a ladder that has been twisted into the shape of a winding staircase, called a double helix.

  5. DNA Structure: Double-helix • This is a computer- generated model of DNA, showing each of the atoms in the molecule

  6. DNA Structure: Subunits http://www3.interscience.wiley.com:8100/legacy/college/boyer/0471661791/structure/dna/dna.htm • Each nucleotide consists of three units: • a sugar molecule called deoxyribose, • de =away, oxy = oxygen • a phosphate group, • and one of four different nitrogen-containing compounds called bases: • adenine (abbreviated A), • guanine (G), • thymine (T), • cytosine (C).

  7. Building DNA Building Blocks

  8. DNA Structure: Nucleotides

  9. DNA Structure • The bases face inward toward each other, forming the rungs of the ladder. • The nucleotides in one DNA strand have a specific association with the corresponding nucleotides in the other DNA strand. • Because of the chemical affinity of the bases, nucleotides containing adenine are always paired with nucleotides containing thymine, and nucleotides containing cytosine are always paired with nucleotides containing guanine.

  10. 4 Nitrogen Bases

  11. A Nucleotide DNA is Made of Two Long Chains of Nucleotides Joined by Hydrogen Bonds http://www3.interscience.wiley.com:8100/legacy/college/boyer/0471661791/structure/dna/dna.htm G and C are complementary as are A and T

  12. The complementary bases are joined to each other by weak chemical bonds called hydrogen bonds. • In 1953 American biochemist James D. Watson and British biophysicist Francis Crick published the first description of the structure of DNA. Their model proved to be so important for the understanding of protein synthesis, DNA replication, and mutation that they were awarded the 1962 Nobel Prize for physiology or medicine for their work.

  13. Winners of the Race to Learn DNA’s Structure – Watson and Crick 53 Years Ago James D.Watson and Francis Crick

  14. chromatin This …. …. not this is what’s found in the cell. DNA is Almost Always Wrapped Around Proteins DNA in a cell is wrapped around proteins and called chromatin.

More Related