Cell Modification

• Cell modification

  1. Occurs after cell division

  2. Newly formed cells are structurally modified

  3. To perform their function efficiently and effectively
• Apical modification

  Type of cell modification found on the apical (top) surface of the cell
• Pseudopods

  • Temporary, irregular lobes formed by amoebas and some other eukaryotic cells
  • Bulge outward to move the cell in order to engulf prey
• Cilia

  • Usually short, hair-like structures that move in waves
  • Motile Cilia
  • Non Motile Cilia
• Flagella

  • Long, whiplike structures
• Villi and Microvilli

  • Finger-like projections that arise from the epithelial layer (surface of cells) in some organs
  • Help to increase surface area for faster and more efficient absorption
• Microvilli

  • Smaller projections
• Extra-cellular Matrix (ECM)

  • Compound secreted by the cell on its apical surface
  • The cell wall is the extra-cellular structure in plant cells that distinguishes them from animal cells
  • Glycoprotein is the main ingredient of ECM in animal cells
• Lateral modification

  Type of cell modification found on the lateral (sides) surface of the cell
• Gap Junction

  • Also known as communicating junctions
  • Closable channels that connect the cytoplasm of adjoining animal cells
• Tight Junction

  • Acts as barriers that regulate the movement of water and solutes between epithelial layers
  • Prevents leakage of ECF
• Adhering Junction

  • Anchors junction on the lateral surface of the cell
  • Similar to the anchoring junction of the basal surface of the cell
• Basal modification

  Type of modification found on the basal (bottom) surface of the cell
• Basal modifications

  • Desmosomes/Hemidesmosomes
• Desmosomes/Hemidesmosomes

  • The anchoring junction on the basal surface of the cell
  • Rivet-like links between cytoskeleton and extracellular matrix components such as the basal lamina that underlie epithelial
  • Primarily composed of keratin, integrins, and cadherins