Cells and microscopy

• Rough endoplasmic reticulum= membrane bound (criterna flattened membrane vesicle) synthesises and transports proteins
• Chloroplast = site of photosynthesis

  • double membrane

  • inner membrane = flattened sacs called thylakoids
• Golgi appratus = modify and secretes proteins


  • flattened sacs
• Cell wall = made of cellulose and supports the cell and provides strength and rigidity

  • interuptions in places called plasmodes
• Plasma membrane = made up of phospholipid bilayer and proteins
• Ribersomes = line up amino acids for proteins

  • made up of one large subnit and small subnit
• Nuclear pores = let MRNA out of nuclear envelope
• Nuclear envelope = nucleus membrane
• Nucleolus = manfacture and assembes ribsomal RNA
• Nuclear plasma = contains chromatin (mix of proteins and DNA)
• Centrioles = To help chromsomes line up in mitosis and meoisis
• Smooth endoplasmic reticulum = membrane bound, continuous with the nuclear envelope


  · No ribsomes

  · Involved in lipid synthesis
• Lysomes = vesicle that contains hydrolytic enzymes that digest foreign matter

  · Formed from Golgi
• Mitochrondria = Where respiration takes place

  · Double membrane - inner folds cristane

  · Matrix contains protein,lipids and ribsomes and DNA
• Cytoskeleton: a microscopic network of protein filaments and tubules in the cytoplasm of many living cells

  • Gives mechanical strength suppourting cell structure

  • Involved in transport - forms track in which organelles can move along
• Laser scanning confocal microscope:

  · Source = laser

  · Displays on a computer

  · Living specimen

  · Internal images

  · Stained with flurocent dye then scanned

  • Magnification = 1,000,000

  • Resolution = 0.88um
• Vacuole = filled with water and solutes

  · keeps cell stablility
• Scanning electron microscope:

  · Specimen coated in heavy metal so elctrons bounce off

  · 1nm resoultion

  · Placed in vacum

  · Not directly viewed

  · 3D external features

  • Magnification = 10x-3,000,000x
• Transmission electron microscope:

  · Source = beam of electron

  · Focussed by electromagnets

  · In vacum so air molecules aren't hit

  · 10-200nm elctron poor pentrating power

  · Internal features

  · High resolution - 71nm

  • Magnfication = 2,000,000x
• Light microscope:

  · Living cells

  · Focused by glass lens to magnify

  · Source = light

  · Cheapest

  · Staining needed when cell is colourless

  • Low resoultion = 0.2um

  • Magnification = 1500x
• Magnification = how many times larger a sample appears than in a real life
• Magnification = image size / actual size

  · Convert everything into um
• Resolution = ablility to distinguish between two points of an image (level of detail)#
• Differential staining = Stains that bind to different cell structures

  • Methylene is an all purpose stain
  • Highlights strutures in light miroscope