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DNA – The Double Helix

DNA – The Double Helix

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DNA – The Double Helix

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  1. DNA – The Double Helix

  2. Recall the nucleus is often called the “control center” because it controls all of the cell’s activities. (eg. Cellular reproduction)

  3. Chromosomes • Are threadlike structures in the nucleus, made of DNA

  4. DNA • Deoxyribose nucleic acid • The nucleic acid that stores and transmits the genetic information from one generation of an organism to the next; it carries the genetic code • Genetic code = the program of the cell which is passed on from one generation to the next

  5. DNA controls the production of proteins within the cell; which proteins are made is determined by the sequence of the DNA. • Proteins are the building blocks of an organism. How you look is largely determined by the proteins that are made. • Proteins make up skin hair and even parts of individual cells.

  6. Structure of DNA • formed of units called nucleotides it is the shape of a double helix (spiralling ladder)

  7. Nucleotide • Each nucleotide contains three basic parts: • A 5-carbon sugar (deoxyribose) • Phosphate group • Nitrogenous base

  8. Nitrogenous bases • There are only 4 types of nitrogenous bases in DNA: • Adenine • Guanine • Cytosine • Thymine

  9. DNA contains millions of bases

  10. Complimentary Base pairing • The force that holds two strands of the DNA double helix together through hydrogen bonds