Cells, Organs and Populations

Cells, Organs and Populations

1. Animal cell

   • Nucleus
   • Cytoplasm
   • Cell membrane
   • Ribosomes
   • Mitochondria

2. Plants

   • Contains all features of animal cell
   • Permanent Vacuole
   • Permanent Vacuole
   • Choloroplast

3. Yeast

   • Is a single celled microorganism
     • Bacteria
       • Cell Wall
       • Cytoplasm
       • Cell Membrane
       • Genetic Material
         • Replaced Nucleus
       • Ribosomes
   • Cytoplasm
   • Cell membrane
   • Nucleus

4. Diffusion

   • Net movement of particles of high concentration to low oncentration
     • bigger difference in concentration = faster diffusion
     • shorter the difference particles travel = quicker the diffusion
     • greater the SA particles diffuse across = quicker the rate of diffusion
   • Occurs in solution and gases
     • Particles are free to move
   • Diffusion occurs in cells
     • Cell Membrane
       • Small substances can diffuse through CM
         • Amino Acids
         • Water
         • Glucose
       • Let things in and out of cell
     • Big molecules cannot diffuse
       • Starch and Proteins

5. Specialised Cells

   • Palisade Leaf adapted for photosynthesis
     • Packed with chloroplast
     • Upper part of leaf to absorb light
     • Tall shape = a lot of surface area
     • Thin shape = space for loads at the top as columns
     • At the top where photosynthesis happens
   • Guard Cells
     • Kidney shape opens and closes stomata in leaf
     • Lots of water
       • Plump and Turgid
         • Stomata opens so gases are exchanged for photosynthesis
     • Short of water
       • GC lose water and become flacicid
         • Makes stomata close stoppnig water vapour leaving
     • Thin outer walls and thickened inner walls
       • Allows opening and closing
     • Controls gas exhange and water loss
   • Red Blood Cell
     • Conclave shape + big surface area and easy pass in capillaries
     • Packed with haemoglobins which absorb oxygen
     • No nucleus = MORE haemoglobins
     • Adapted to carry oxygen