C e l l ular O r g anelles and Protein Synthesis

The Nucleus: Control Center and DNA Hub

• Nucleolus:

  • Located on the side of the nucleus.

  • A large bundle of DNA held together by thousands of proteins.

  • Primary site of RNA production, which is then sent out for translation.

• Chromatin:

  • Refers to all the DNA inside the nucleus when the cell is not dividing.

  • Consists of DNA wrapped around various proteins, especially histones.

  • Eukaryotic gene expression mechanisms are significantly more complex than in prokaryotic organisms.

  • The complex wrapping ensures DNA is organized and accessible for necessary RNA message production to make proteins.

• Chromosomes:

  • During cell division, all chromatin condenses into structures called chromosomes.

  • Often depicted as the familiar X-shape, with each half (sister chromatid) being an identical copy of the DNA, joined at a centromere. This structure ensures accurate distribution of genetic material to daughter cells during cell division.