Cell structure

• Why is the cell membrane important?

  • Controls exchange between cell and its environment
  • Acts as a barrier which separates the cell content and its environment
  • Controls movement of substances into and out of the cell
• Organisms made of cell with membrane-bound nuclei are known as eukaryotes while cells lacking membrane-bound nuclei are known as prokaryotes
• Example of prokaryotes:

  Bacteria
• Examples of eukaryotes:

  • Animals
  • Plants
  • Fungi
• There are two types of microscopes:

  Light microscope

  Electron microscope
• Function of cell membrane:

  Controls exchange of materials between the cell and its environment.
• The deeply staining material in the nucleus is the chromatin. Chromatin is a mass of coiled threads of DNA and proteins.
• Chromatin contains DNA molecule which contains the instructions(genes) that control the activity of the cell.
• The nucleolus is a structure within the nucleus that is involved in the production of ribosomes
• An organelle can be defined as a functionally and structurally distinct subcellular structure.
• Ribosome - site of protein synthesis
• Vacuole - storage of water, waste products or pigments
• Mitochondria - site of aerobic respiration
• Golgi apparatus - modifies and packages proteins made by ribosomes
• Lysosome - breaks down unwanted material inside cells