Extra

• What are cell junctions?

  Structures that connect cells and facilitate communication
• What is the function of tight junctions?


  To create seals between cells to prevent leakage of extracellular fluid
• Where are tight junctions commonly found?

  In the intestinal lining
• How do desmosomes function in tissues?

  They act like rivets, fastening cells together in strong sheets
• In which type of tissue are desmosomes commonly found?

  Muscle tissue
• What role do gap junctions play in cell communication?


  They form channels that allow ions and small molecules to pass directly between neighboring cells
• Why are gap junctions particularly important in heart cells?


  They facilitate cell communication
• What is the primary function of the cytoskeleton?

  To provide structural support and facilitate movement within the cell
• What are microtubules?

  Hollow rods that help maintain cell shape and guide organelle movement
• What role do microtubules play during cell division?


  They are involved in chromosome separation
• What are microfilaments also known as?

  Actin filaments
• What is the function of microfilaments in cells?

  They support the cell's shape and are important for cell movement
• What is the role of intermediate filaments?


  To provide strength and stability, especially in skin cells
• What is the endomembrane system and its components?


  • A series of organelles that produce, process, and transport molecules
  • Components include:
  • Endoplasmic reticulum (rough and smooth)
  • Golgi apparatus
  • Lysosomes
  • Vesicles
  • Plasma membrane
• What are the two forms of the endoplasmic reticulum (ER)?

  Rough ER and smooth ER
• What is the function of rough ER?

  To synthesize proteins due to the presence of ribosomes
• What does smooth ER do?

  Involved in lipid synthesis and detoxification
• What is the role of the Golgi apparatus?

  To modify, sort, and package proteins and lipids for transport
• What do lysosomes contain?

  Enzymes that break down macromolecules
• What are vesicles?

  Small transport containers that move materials between organelles and the plasma membrane
• What is the function of the plasma membrane?

  To regulate what enters and exits the cell
• What are the functions of the extracellular matrix (ECM) and cell walls?


  • ECM (in animal cells):
  • Composed of glycoproteins like collagen
  • Provides structural integrity, cell signaling, and adhesion
  • Cell walls (in plants, fungi, and some prokaryotes):
  • Made primarily of cellulose in plants
  • Provides protection, structural support, and prevents excessive water intake
• What is the ECM composed of?


  Glycoproteins like collagen
• What is the primary function of the cell wall in plants?


  To provide protection and structural support
• How does the cell wall prevent excessive water intake in plants?


  By providing structural support and protection
• Cell walls give plants their shape and support them against gravity.
• The cell wall is made up of polysaccharides, which are long chains of sugar molecules.
• Plant cell walls also contain lignin, a complex organic polymer that provides strength to the cell wall.
• Plant cells have a rigid cell wall made up of cellulose fibers that surround the cell membrane.
• The cell wall allows plant cells to maintain turgor pressure, which helps them stand upright and resist bending or breaking under tension.
• bung


  dung
• What is the basic unit of life?

  Cells
• How many cells does every living organism consist of at least?


  At least one cell
• What is the approximate size of cells?

  Around 1 micrometer
• What does the cell membrane do?


  It serves as a boundary containing the cytoplasm
• What does the cytoplasm consist of?


  The fluid and all internal structures of the cell
• In which type of cells is DNA stored in a membrane-bound nucleus?


  Eukaryotic cells
• Where does DNA float freely in prokaryotic cells?

  In the cytoplasm
• What is the function of ribosomes in cells?


  They act as protein factories
• From what do ribosomes produce proteins?


  From genetic instructions found in RNA