Cell structure

• preparing a microscope slide

  obtain a thin transverse section of a tissue

  add a singular drop of water using a pipette

  stain the tissue with an appropriate dye

  add a cover slip carefully to avoid trapping air bubbles
• magnification

  a factor by which the image is larger than the actual specimen
• resolution

  smallest separation distance at which two objects close together can be distinguished as two seperate objects
• anabolic

  formation of a larger product from two small reactants
• catabolic

  breakdown of one large reactant into two small products
• staining

  increase contrast

  make cells more visible

  identify different cellular components
• light microscope

  2000 x magnification

  200 nm resolution

  living and non living
• laser scanning confocal

  200 nm

  2D and 3D image

  laser beam scans an object by pixel

  coloured image

  ultrastructure visible

  different depths within a sample
• electron transmission

  0.2 nm

  1000000 magnification

  internal structures

  non-living specimen only

  black and white image

  only 2D image

  organelles visible
• electron scanning

  1000000 magnification

  3-20 nm

  non-living only

  surface view
• microtubules

  can be prevented from functioning by a respiratory inhibitor

  are involved in moving chromosomes from the equator to the poles of the cell during mitosis
• label the diagram

  y -> plasma membrane

  x -> cell wall

  z -> vacuole membrane

  
• endosymbiotic theory evidence

  mitochondria contain ribosomes that are smaller than those found in the cell cytoplasm

  mitochondria are a similar size to bacteria

  chloroplasts have their own circular DNA
• ribosomes

  80S in plant and animal cells

  protein synthesis

  25 nm diameter
• RER

  extended system of membrane sacks

  site of protein modification

  encrusted with ribosomes
• golgi body

  sacks of flattened membranes

  modifies proteins

  makes lysosomes
• lysosomes

  golgi vesicle that releases lysozyme
• plasma membrane

  7 nm diameter
• mitochondria

  1-10 micro meters
• permanent vacuole

  sap that supports the plant
• cell wall in algae

  glycoproteins
• cell wall

  provides mechanical strength whilst remaining permeable
• chloroplasts

  3-10 micrometers
• flagella

  involved in the motility of the cell
• centrioles

  form spindle fibers
• yeast cell division

  budding
• digestive enzyme pathway

  rough endoplasmic reticulum → Golgi apparatus → secretory vesicle
• cytoskeleton

  1. mechanical strength
  2. aiding transport of organelles (mrna to ribosomes and vesicles to plasma membrane)
  3. enabling whole cell movement
• how are vesicles moved inside the cell

  attach to cytoskeleton

  moved by a motor protein