Biology - Module 1

• Cells are the basic structural and functional units of life
• Prokaryotic cells lack a nucleus; their genetic information is found in the nucleoid. They lack membrane-bound organelles and are generally smaller in size and simpler in structure. They are unicellular. E,g. Bacteria, Archaea
• Eukaryotic cells have a nucleus, membrane-bound organelles, and a cell membrane. They are generally larger in size and more complex in structure. It can exist as unicellular or multicellular. E,g. Algae, Yeast, Protists, Fungi, Plants, Animals
• Endosymbiotic Theory: Suggests eukaryotic cells evolved from prokaryotic cells
• Endosymbiosis: A type of symbiosis in which one organism lives in the other
• Mitochondria and Chloroplast contain DNA
• Technology to determine cell structure

  Light microscope, Fluorescent microscope, Electron microscopes (TEM and SEM), Computer enhanced technology, Stains and dyes
• Resolution: Ability of the microscope to distinguish between two closely spaced objects
• Magnification: Increase in size, typically expressed as a ratio
• Light Microscope


  Uses light and lenses to magnify specimens, suitable for observing living and non-living specimens
• Fluorescent Microscope


  Uses ultraviolet light to excite fluorescent molecules in specimens, can visualise specific structures or molecules labelled with fluorescent dyes and offers higher resolution and sensitivity
• Electron Microscope


  Uses electron beams and electromagnets to magnify specimens, cannot view living specimens, two main types: SEM and TEM
• Transition Electron Microscopes (TEM)


  Produces detailed, two-dimensional images of internal structures, electrons are transmitted through the specimens
• Scanning Electron Microscope (SEM)


  Produces detailed, three-dimensional images of specimen surfaces, bombards the surface of a specimen with a beam of electrons, very detailed images but cannot give internal details
• Cellular Respiration


  Responsible for the production of ATP, carried out by cells, inside the mitochondria
• Glucose + Oxygen --> Carbon Dioxide + Water + Energy