1.1 Introduction to cells

1.1 Introduction to cells

1. Cell theory

   • smallest life unit
   • from pre-existing cells
   • living organisms-cells

2. Unicellular organisms

   • carry all functions
     • metabolism-excrete respire
     • response to stimuli
     • growth
     • reproduction
     • homeostasis
     • nutrition

3. Surface area: volume

   • cellsize limited
     • diffusion of exchange materials
   • v increase more than s.a
     • leads to problem
       • necessary exchange limited;
       • overcome
         • protruding extensions
         • flattening cells

4. Emergent properties

   • Multicellular organisms
     • achieve more than = of each cell could do
       • cells interact

5. Magnification

   • magnified size / real size
   • using microscopes
     • TEM
       • study internal
     • SEM
       • study outer cells
     • light compound mic
       • objective lens power * eyelens power

6. Stem cells-unspecialised

   • totipotent
     • embryo
       • high potency of all cell
   • pluripotent
     • zyogote --> blastocyst
       • apart potency
   • multipotent
     • limited potency
   • differ normal cells
     • undifferentiated
     • self-sustaining
   • therapeutic use
     • bone marrow transplant
       • treat leukaemia
     • Stargardt's disease
       • retinal pigment epithelial cells