Cellular Organisation and Function
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This section looks at the cell as the basic unit from which most living organisms are constructed. The pats of a cell are identified and their functions considered. Differences between plant and animal cells performing different functins within a plant or animal are discussed. The particular role of the cell membrane in the uptake or loss of water is examined.
All living organisms are made up of cells
Know the diagram of both plant and animal cell, as well as labelling
(editors note: will add pictures of above at a later date)
Differences between plant and animal cells:
|
Plant Cell Wall |
Animal no cell wall |
|
Permanant vacuole |
temp. vacuole |
|
chloroplast |
no chloroplast |
|
starch grains |
glycogen granules |
|
regular shape |
irregular shape |
Definitions
Nucleus
- controls chemical reactiosn
- contains information to make living organism
- tells cell what to do
Cytoplasm
- where chemical reactions take place
Cell Membrane
- controls what comes in and goes out of cell
Cell Wall
- made of cellulose
- gives cell strength and support
Vacuole
- contains salt and suger solution, called cell sap
- supports cell
Chloroplast
- contains chlorophyll
- for photosynthesis
Mitochondria
- release engery by cellular respiration
A group of specialised cells working together are called tissue
Osmosis and Diffusion
Diffusion is the movement of molecules from an area of high concentration to an area of low concentration., until equilibrium is reached.
- Larger Molecules - slower rate of diffusion
Osmosis is the movememtn of water molecules from an are of high concentration (weak solution) to an area of low concentration (strong solution), though a partially permeable membrane, until equilibrium is reached.
- when plant cell vacuoles swell up, cells become turgid
- when lacking water, the plant wilts, and the cells become flacid
- when lots of water leaves, cytoplasm comes away from cell wall, this is called plasmolysis.
About the Author
by: Admin
Total views: 7210
Word Count: 853
Date: Sun, 21 May 2006 Time: 12:00 AM
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