2.1 Cell structure

• resolution is the clarity of an image on a microscope; the higher the resolution, the clearer the image.
• Magnification= Image size/ actual size
• A light microscope beams a light through biological object, in a 2D image. The resolution is 200nm and total magnification x1500.
• A laser scanning microscope beams a laser focused on the specimen, in 3D images and computer generated colour.
• A TEM microscope passes electrons through denser material, creating a 2D image. Maginifiaction ranges from x500,000 to x2,000,000
• The eyepiece graticule is a measuring device that is used to measure the size of an object, acting as a ruler when you view an object under the microscope.
• A stage graticule is a precise measuring device used to measure the distance between two points on the stage of a microscope.
• A eukaryotic cell is a cell that contains a nucleus and other membrane-bound organelles.
• A prokaryotic cell is a single-celled organism that does not have a nucleus.
• Total magnification= objective magnification x eyepiece magnification
• The SEM microscope bounces electrons of a specimen to produce a 3D image. The total magnification is x100,000 - x200,000. The specimen must be dead as it is vacuumed and coated in metal.
• Smooth endoplasmic reticulum is a membrane bound organelle that synthesises and transports lipids
• Nucleus: contains genetic material and controls cell activities.
• Cytoplasm: the jelly like substance inside cells where chemical reactions take place.
• Cell wall: provides support and protection to plant cells.
• Chloroplasts: contain chlorophyll which absorbs light energy used in photosynthesis.
• Vacuole: stores water and waste products.
• Ribosomes: site of protein synthesis.
• Plasma membrane: regulates what enters or leaves the cell.
• Mitochondria: produce ATP through respiration.
• Golgi apparatus: modifies, packages and distributes proteins within the cell.
• Rough endoplasmic reticulum: is the site of protein synthesis and transportation of protein.
• Cytoskeleton: provides structural support to the cell.
• Cytoskeleton provides mechanical strength to cells, aiding transport within cells and enabling cell movement.