1. Cell Structure

2. Revision AnimalPlant

3. Animal Cell

4. Plant Cell

5. Organelles Nucleus Bounded by a double membrane with pores Chromosomes in loosely coiled state called chromatin Chromosomes contain DNA Nucleolus – a dense body used to produce ribosomes 6μm in diameter

6. Electron micrograph of a nucleus

7. Endoplasmic reticulum Two types: 1.Rough endoplasmic reticulum (RER) 2.Smooth endoplasmic reticulum (SER)

8. Rough Endoplasmic Reticulum Parallel flattened cavities lined with thin membranes 4nm thick. Attached to the membrane are ribosomes. Used for protein transport

10. Smooth Endoplasmic Reticulum Tubes rather than flattened stacks Synthesis and transport of lipids and steroids

12. Golgi Apparatus Stack of flattened cisternae Formed by fusion of vesicles from the RER Vesicles pinch off the trans face and move to the cell membrane.

14. Mitochondria Diameter 1.0 μm, length 2,5 μm Surrounded by 2 membranes Inner membrane folded to form cristae Matrix fluid inside Used for producing ATP in aerobic respiration

15. Contains circular DNA Contains ribosomes (70S)

16. Ribosomes They are used for protein synthesis

17. There are two types of ribosomes: The smaller ones (70S) are found in mitochondria and chloroplasts. The larger ones (80S) are found in the cytoplasm and attached to the RER

18. Lysosomes Contain digestive enzymes. Destroys bacteria Destroys old organelles Can destroy whole cell

20. Chloroplasts

21. Double membrane Inside is the stroma Thylakoids are membranes stacked on top of each other to form a grana. The membranes contain chlorophyll pigments Contains 70S ribosomes and small circular DNA 5 – 10 μm in length

22. Centrioles A barrel shaped organelle found only in animal cells Used in cell division. It is a pin-wheel formation of 9 groups of 3 microtubules.

24. Microvilli Minute projections of the cell wall Increases surface area 1 μm long and 0.8 μm wide

26. Cell wall Made of cellulose Gives plant cells shape. Can be lignified to make it even stronger.

28. Permanent Vacuole and Tonoplast The tonoplast is a semi-permeable membrane surrounding the vacuole. The vacuole stores food, water, and wastes. It gives support to soft structures, such as leaves.

30. Plasmodesmata Only found in plant cells microscopic channels which traverse the cell walls of plant cells enable transport and communication between them.

32. Cell Membrane

33. a semi-permeable membrane

34. Prokaryotic Cells Unicellular 1 – 5 μm diameter Lack membrane-bound organelles Naked, circular DNA 70S ribosomes Peptidoglycan cell walls