Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Cells as the basis of life


Published on

Senior Biology - Cells as the basis of life - For additional resources visit:

Published in: Education
  • Be the first to comment

Cells as the basis of life

  1. 1. Cells as the basis of life Sarah Jones
  2. 2. All LIVING things are made of CELLS. Fibroblasts are cells that help maintain tissue structure by secreting proteins like collagen and elastin -
  3. 3. The Discovery of Cells In the seventeenth century, Robert Hooke looked at thin slices of cork under a microscope that he had made from lenses. He observed small box-like shapes inside the cork. He called the little boxes that he saw cells.
  4. 4.
  5. 5. Electron Microscopy Images Of Coffee
  6. 6. SEM Image of Trabecular bone
  7. 7. Unicellular organisms – single-celled organisms. Multicellular organisms – have specialised cells that carry out specific functions. Unicellular Algae –
  8. 8. Carry out all of the functions of life M ovement R espiration S ensitivity G rowth R eproduction E xcretion N utrition Unicellular Organisms Diatom –
  9. 9. Under the five kingdom system cells can be divided into two basic types.
  10. 10. Prokaryotic cells - simple cells without distinct membrane bound organelles or nucleus.
  11. 11. Eukaryotic cells - more complex with membrane bound organelles and nucleus.
  12. 12. Animal Cell
  13. 13. • Exist as part of a multicellular organism. • Specialisation of cells into many types (cell differentiation). • Possess nucleus and membrane bound organelles.
  14. 14. Plant Cell
  15. 15. • Exist as part of a multicellular organism. • Specialisation of cells into many types (cell differentiation). • Possess nucleus and membrane bound organelles.
  16. 16. Plant vs Animal Plant and animal cells have many similarities because they are both eukaryotic. They also have some differences:
  17. 17. Plasma Membrane • The surface of exchange for materials between the inside and outside of the cell. • IN – oxygen, nutrients and water • OUT – carbon dioxide, waste and products such as proteins
  18. 18. Plasma Membrane Function 1. Hold cell together 2. Control what goes in and out – diffusion, osmosis, active transport 3. Protect the cell 4. Allow the cell to recognise and be recognised – cell signaling and immunity 5. Bind to other cells and molecules 6. A sit for biochemical reactions – enzymes, areas for reactions
  19. 19.
  20. 20. Diffusion • Larger cells require more resources to be imported and more products to be exported. • As cells get larger the SURFACE AREA to VOLUME RATIO gets smaller. • Increasing cell size – less efficient exchange process.
  21. 21. Brownian Motion – the random movement of particles in a liquid or gas. Due to Brownian motion particles will diffuse evenly through the system over time.
  22. 22. Diffusion is the passive net movement of molecules from regions of high concentration to low concentration.
  23. 23. Facilitated diffusion is the passive net movement of particles from regions of high concentration to low concentration, through selectively permeable membrane (plasma membrane), facilitated by carrier proteins.
  24. 24.
  25. 25. Osmosis Osmosis is the passive net movement of water molecules from regions of low solute concentration to high solute concentration, through partially/selectively permeable membrane.
  26. 26. Osmosis is also movement down a concentration gradient –we are considering the movement of water molecules, not the solute molecules.
  27. 27. Active Transport Active transport uses energy (ATP) to move molecules against a concentration gradient, using membrane protein pumps.
  28. 28.
  29. 29. Endocytosis
  30. 30. Exocytosis
  31. 31. Parts of a Generalised Animal Cell
  32. 32. • Contains the chromosomes (genetic information) for the cell. • Controls the activities of the cell. Nucleus
  33. 33. • Double membrane - outer membrane and inner membrane. • Inner membrane is folded forming cristae. • The interior contains an organic matrix containing chemical compounds. • Site of aerobic respiration. Mitochondria
  34. 34. Rough Endoplasmic Reticulum • A membrane system of flattened parallel cavities which are interconnected and covered with ribosomes. • An intracellular transport system.
  35. 35. Golgi Apparatus • Consists of a stack of flattened cavities which package substances produced by the cell into vesicles. • These vesicles can fuse with the cell membrane (exocytosis) or become lysosomes (digestive vesicles).
  36. 36. Plant Cell Walls • The main component of plant cell walls is cellulose. • Cellulose molecules are arranged in bundles called microfibrils. • The function of the plant cell wall is to provide strength and support the plant.
  37. 37. Photosynthesis
  38. 38. Chloroplast
  39. 39.
  40. 40. Cellular Respiration Plants
  41. 41. Cellular Respiration Humans
  42. 42. Comparing Cellular Respiration and Photosynthesis
  43. 43.
  44. 44. Prokaryotic organisms are commonly called bacteria. They are cells with a simple structure. They have no membrane around the nucleus and lack any membrane bound organelles.
  45. 45. Blue-green bacteria make their own food by photosynthesis.
  46. 46.
  47. 47. Prokaryotic Cell Parts • Cell Wall – protective protein-based coating. • Plasma Membrane – selectively permeable. • Pili – attach to other bacteria for DNA transfer. • Cytoplasm – contains enzymes for metabolic reactions. • Nucleoid – closed-loop of bacterial DNA. • Ribosomes – protein synthesis – transcription and translation. • Flagella – causes movement.
  48. 48.
  49. 49. Prokaryotic Reproduction – Binary Fission
  50. 50. Cell Division • For an organism to grow larger it needs to produce more cells – and each new cell needs a copy of the organism’s DNA. • Tissue Repair • Asexual Reproduction
  51. 51. Mitosis
  52. 52.