GM

A+P: Cells continued

Mitochondria

  • Function of Mitochondria

    • Primary function: Produce ATP (adenosine triphosphate), which serves as the energy currency for cells.

    • ATP is crucial for various cellular processes and activities.

  • Structure of Mitochondria

    • Mitochondria have distinctive structures that can be recognized under different microscopy techniques.

      • Depending on the cut, they may appear circular in cross-section.

    • Notable feature: Cristae

      • These are the inner foldings within the mitochondria that increase surface area for ATP production.

      • Cristae are visible in electron micrographs, even when the mitochondria are cut in cross-section.

Histology and Cell Structure

  • Importance of Cells

    • Cells are the basic unit of life and can be studied through histology, or the microscopic examination of tissues.

    • Histological analysis allows observation of structures like mitochondria and others, using light and electron microscopes.

  • Different Microscope Views

    • Mitochondria appear as the largest structure in cells, observable in both light (colored images) and electron (black and white images) micrographs.

Cilia

  • Function of Cilia

    • Cilia are finger-like projections extending from the plasma membrane that can move freely.

    • They play a role in moving mucus over cell surfaces, directing it towards the throat and away from the lungs.

    • Visually represented as pink hair-like structures on the cell surface, aiding in mucus clearance.

Cell Adhesions: Desmosomes

  • Function of Desmosomes

    • Desmosomes are specialized structures that hold cells together, enhancing tissue integrity.

    • They create mechanical linkages between adjacent cells, functioning like Velcro.

    • Important in maintaining structural cohesion among cells in tissues that endure mechanical stress.

  • Visualization of Desmosomes

    • In histological images, desmosomes appear as two parallel dark lines between adjacent cells due to dense protein structures.

    • Laboratory sessions may include viewing desmosomes in prepared slides for better understanding of cell-to-cell adhesion.

Summary

  • Mitochondria are critical for ATP production in cells, marked by their unique cristae structure.

  • Key cell structures, including cilia and desmosomes, contribute to essential functions such as mucus movement and providing structural integrity, observable through targeted histological techniques.