Tuesday, November 25, 2008

Functions of cell structure

Plasma membrane
  • Serves as a boundary between the cell and its environment.
  • Control the passage of materials in and out of cells.

Cell wall

  • Gives support to the plant cell as a whole by providing mechanical strength.
  • Allows the movement of water.
  • Prevent plant cell from bursting.

Cytoplasm

  • Contains substances such as enzyme, oil droplets, glycogen granules (in animal cell only), and starch grains (in plant cell only).

Nucleus

  • Contains the genetic material of a cell in the form of chromosomes.
  • Acts as a control centre for the activities of a cell.
  • Produces ribosomes and ribonucleic acids (RNA).Plays as essential roll in cell division.

Rough endoplasmic reticulum

  • Involves synthesis of proteins.
  • Provides a pathway for the transport of materials in the cell (intracellular transport system).
  • Provides a large surface area for chemical reaction.

Smooth endoplasmic reticulum

  • Produces lipids.

Mitochondria

  • Site of aerobic cellular respiration.
  • Produces adenosine triphosphate (ATP).

Golgi apparatus

  • Collects, packs and distributes molecules synthesized in the cell.
  • Products glycoproteins, polysaccharides and secretory enzymes.
  • Forms lysosomes.Transports and stores lipids.

Lysosome

  • Digests materials which the cell consumes.
  • Destroys unwanted or worn out organelles.
  • Completely breaks down the cell after its death.Releases enzymes outside the cell to digest external material.

Ribosome

  • Site of protein synthesis.

Centriole

  • Forms the spindle during the cell division of animal cell.

Vacuole

  • Stores anthocyanins which provide various colours to fruits and flowers.
  • Stores sugars and amino acids in its sap.
  • Stores organic wastes in vacuoles of leaf cellsSupports herbaceous plants by turgor pressure.

Chloroplast

  • Site of photosynthesis.