Chapter 2: Protoplasm and the Cell

• Protoplasm - Described as the " physical basis of life", general term for the living substance including the cytoplasm and nucleus of the cell
• Homogenous – as seen in the exoplasm of the amoeba
• Granular – as seen in young and undifferentiated cells(immature cells)
• Reticular – fine lattice like appearance
• Fibrillar – appearance of fine fibril
• Most abundant elements of Protoplasm

  • oxygen
  •  hydrogen
  •  carbon
  •  nitrogen
• Protein − Constitutes more than half of the dry weight of the cell
• DNA - Genetic material found mainly in the nucleus
• RNA - Present both in the nucleus and the cytoplasm; carries message from the nucleus to the cytoplasm & serve as a template for the synthesis of proteins.
• Carbohydrates − Provides the chief source of energy of most cells in the form of glucose and glycogen which is  the storage form of glucose
• Lipids − Major component of the membrane system of the cell and can also serve as an energy source for the cell
• Spherical cells- rounded cells
• Squamous cells- Flattened scale like elements
• Fusiform cells - Spindle shaped with thick middle portions and tapering ends
• Stellate cells - Have irregular protoplasmic process and is roughly star shaped
• Amorphous cells - Cells without any definite maintained shape