The Cell The smallest functional unit of life

1. Animal Cell The CellThe smallest functional unit of life Plant Cell

2. I. The Cell Theory A.Allliving things are made of cells. B. Cells are the basic unit of structureandfunction C. All cells arise from preexistingcells.

3. II. Cell Size A.Smallcells function more efficientlythan large cells. B. If a cell’s surface to volume ratiois too low, substances can not easily enterorleavethe cell. Smallest cell – mycoplasma largest – ostrich egg yolk

4. III. Common Features of Cells A.Cell membrane– encloses the cell and separates the cell interior from its surroundings B.Cytoplasm– the cell interior which includes gases, nutrients and waste C. Cytoskeleton– system of microscopic fibers that support the cell D. Cellwall – outer structure which supports and protects the cell E. Ribosomes– small structures in every cell where protein synthesis occurs F. DNA– regulates cellular activities * some specialized cells like red blood cells lose their DNA

5. IV. Prokaryotes Smallest and simplest cells A. Singlecelled organisms B. Lack anucleus C. Lack membrane bound organelles D.Can live in a broadrangeof environments

6. E. Have a cell wall F. Lack internalsupport G. Many have flagella – long, threadlike projections that enable movement

7. V. EukaryotesCells with internal compartments A. Single celled or multicellular B. Have a nucleuswhere DNA is kept

8. C. Have membrane bound organellesthat carry outspecific functionswithin the cell. D. Have a cytoskeletonwhich provides internal support. E. Some have cilia– short, hair like structures that aid in movement F. Includesanimals, plants, fungiand protists.

9. VI. Cell Organelles A. Cytoskeleton– network of protein filaments that support the cell and aid in movement. B.Cytoplasm– region inside the membrane that includes the fluid, the cytoskeleton and all the organelles except the nucleus. C.Cell membrane– a phospholipidlayer that covers a cell’s surface and regulateswhat comes into and out of the cell.

10. D. Nucleus– a membrane bound organelle that contains the cell’s DNAand regulatesgrowth, metabolism and reproduction. 1. Nuclear envelope– membrane which separates the nucleus from the cytoplasm 2. Nuclear pores– channels which allow materials to pass in and out of the nucleus 3. Chromatin– coiled up DNA 4. Nucleolus– produces ribosomes

11. E. Ribosomes– tiny structures composed of RNA and protein that make proteins F.Endoplasmic reticulum– a system of membranes that assist in the production, processingandtransportof proteins and lipids. F.Golgi Appartus–helps make and packagematerials to be transported out of the cell.

12. G. Vessicle–small sacs that holdandtransportsubstances H. Lysosome– vessicle which breaks downoldand used cell parts (found in animal and fungal cells)

13. I. Mitochondrion– organelle surrounded by two membranes that is the site of cellular respiration, produces ATP (energy) J. Centrioles– organelles which help incell division (found in animal cells)

14. VII. The Plant Cell A.CellWall–rigidstructure that surrounds the cell membrane and provides supportto the cell.

15. B.CentralVacuole – large membrane bound space thatstoreswaterand other substances; provides rigidity C. Chloroplast– found in plant and algae, contains a greenpigment (chlorophyll) – where photosynthesisoccurs

16. VIII. Organization of Living Things

17. IX. Cell Specialization A. The design and shape of a cell is determined by its function and the conditionsunder which it works. B. Unicellular organisms tend to have fairly complex cells, which makes sense considering that these organisms must depend on only one cell to do everything. C. Multicellular organisms exhibit much greater specialization. http://highered.mcgraw-hill.com/sites/dl/free/0078617022/164155/00035805.html

18. www.cellsalive.com/cells/3dcell.htm The End