basic components of living systems

• nucleolus

  • area within the nucleus responsible for producing ribosomes
  • composed of proteins and RNA
• mitochondria

  • site of the final stages of cellular respiration
  • inner membrane highly folded to form cristae
  • fluid interior called the matrix
• vesicles

  • membranous sacs that have storage and transport roles
  • single membrane with fluid inside
  • transport material inside the cell
• lysosomes

  • specialised forms of vesicles
  • contain hydrolytic enzymes
  • break down waste material in cells
  • break down pathogens
• cytoskeleton

  • microfilaments responsible for cell movement
  • microtubules act as tracks for the movement of organelles
  • intermediate fibres- give mechanical strength to cells
• centrioles

  • two associated centrioles form a centrosome
  • centrosome involved in the assembly and organisation of spindle fibres
• flagella

  • enable cell mobility
• cilia

  • stationary cilia have function in sensory organs
  • mobile cilia beat in a rhythmic manner to create a current
• chloroplasts

  • responsible for photosynthesis
  • fluid enclosed- stroma
  • flatterned membrane sacs- thylakoids
  • stacked thylakoids- granum
  • grana contain chlorophyll
• magnification- the increase in size of a specimen
• resolution- the ability to distinguish two objects from each other
• magnification= image size/ object size
• laser scanning confocal microscopy- focused light moved across a specimum causing flourecence
• scanning electron microscope- beam of electrons transmission through a specimen and focused to produce an image
• transmission electron microscope- beam of electrons transmitted through a specimen and focused to produce an image
• light microscope- objective lens produces magnified image. its magnified again by eyepiece graticule
• dry mount- solid specimens used
• wet mount- specimens suspended in a liquid
• squash slides- lens tissue used to gently press down the cover slip
• smear slides- edge of the slide used to smear the sample
• protein synthesis

  1. proteins are synthesised on the ribosomes bound to the rough ER
  2. they are packaged into transport vesicles
  3. vesicles move towards the golgi apparatus via cytoskeleton
  4. secondary vesicles fuse with cell surface membrane- exocytosis