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Monday, 24 November 2014

Title :

Cells as the basis of life

Author :

Sarah Jones

Number of slides:


Slideshow :

Content transcript :

1. Cells as the basis of life Sarah Jones
2. All LIVING things are made of CELLS. Fibroblasts are cells that help maintain tissue structure by secreting proteins like collagen and elastin -
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. Unicellular organisms – single-celled organisms. Multicellular organisms – have specialised cells that carry out specific functions. Unicellular Algae –
5. Unicellular Organisms Carry out all of the functions of life M ovement R espiration S ensitivity G rowth R eproduction E xcretion N utrition Diatom –
6. Under the five kingdom system cells can be divided into two basic types.
7. Prokaryotic cells - simple cells without distinct membrane bound organelles or nucleus.
8. Eukaryotic cells - more complex with membrane bound organelles and nucleus.
9. Animal Cell
10. • Exist as part of a multicellular organism. • Specialisation of cells into many types (cell differentiation). • Possess nucleus and membrane bound organelles. • Many different types.
11. Plant Cell
12. • Exist as part of a multicellular organism. • Specialisation of cells into many types (cell differentiation). • Possess nucleus and membrane bound organelles.
13. Plant vs Animal Plant and animal cells have many similarities because they are both eukaryotic. They also have some differences:
14. 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 
15. 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
17. 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.
18. 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.
19. Diffusion is the passive net movement of molecules from regions of high concentration to low concentration.
20. 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.
22. 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.
23. Osmosis is also movement down a concentration gradient –we are considering the movement of water molecules, not the solute molecules.
24. Active Transport Active transport uses energy (ATP) to move molecules against a concentration gradient, using membrane protein pumps.
26. Endocytosis
27. Exocytosis
28. Parts of a Generalised Animal Cell
29. Nucleus • Contains the chromosomes (genetic information) for the cell. • Controls the activities of the cell.
30. Mitochondria • 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.
31. Rough Endoplasmic Reticulum • A membrane system of flattened parallel cavities which are interconnected and covered with ribosomes. • An intracellular transport system.
32. 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).
33. 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.
34. Photosynthesis
35. Chloroplast
37. Cellular Respiration Plants
38. Cellular Respiration Humans 
39. Comparing Cellular Respiration and Photosynthesis 
40. Golgi Apparatus
41. 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.
42. Blue-green bacteria make their own food by photosynthesis.
44. 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.
46. Prokaryotic Reproduction – Binary Fission 
47. 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
48. Mitosis
49. Prokaryotic organisms are commonly called bacteria.
50. Blue-green bacteria make their own food by photosynthesis.
51. Prokaryotic Cell
52. Prokaryotic Cell Parts
54. Prokaryotic Reproduction – Binary Fission
55. Cell Division
56. Mitosis
57. Mitosis
58. Comparision of meiosis & Mitosis


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