B2.1 Cells and Simple Cells Transport

B2.1 Cells and Simple Cells Transport

1. Different Cells

   • Animals
     • nucleus
       • controls cell activities, and it is where genetic material is contained
     • cell membrane
       • holds the cell content together
     • mitchondria
       • energy is released from respiration- glucose is burned to release the energy
     • cytoplasm
       • where most chemical reactions occur usually via enzyme catalysts
     • ribosomes
       • protein-synthesis from amino acids occur
   • Plants
     • cell wall
       • made of cellulose strengthens the cell and plant structure.
     • chloroplasts
       • absorb sunlight energy to make food via photosynthesis
     • permanent vacuole
       • filled with cell sap that contains sugars and mineral salts
     • + all the other parts of cell like an animal cell.
   • Bacteria
     • cell wall
     • cytoplasm
     • large chromosomal ring of DNA
     • Plasmid ring of DNA
       • NOT in a distinct nucleus, more of a jumbled cluster.
     • Flagella
     • NO NUCLEUS
   • Yeast is a single-celled organism
   • Specialised Cells
     • Animals
       • Red Blood Cells
         • carry oxygen via their haemoglobin molecules
       • White Blood Cells
         • help out in the immune system
       • Gamete Cells
         • Sexual Reproduction cells (egg cell and sperm cell)
     • Plants
       • Palisade Leaf structures are adapted to suit the photosynthesis site.
       • Guard cells open and close the stomata- this allows oxygen and carbon dioxide to pass in or out.
   • Diffusion- when dissolved substance can come into or out of the cell from the cell membrane.
     • It is the spreading of gas or substance in solution, which results in the movement from a region of high concentration to a region of low concentration
     • it is a spontaneous movement
     • the greater the difference in concentration, the faster the rate of diffusion.
     • only relatively small molecules can diffuse through the cell membrane
       • e.g. amino acids, not proteins
       • or sugars like glucose and not carbohydrates like starch.
     • oxygen required for respiration diffuses through the membrane.