Cell Featureshttp://personal.tmlp.com/Jimr57/textbook/chapter3/images/cell1.jpg
http://biology.clc.uc.edu/graphics/taxonomy/plants/spermatophyta/angiosperms/dicotyledonae/Rutaceae/Gas%20Plant/JSC%200005%20Gas%20Plant.JPG
http://www.rds-online.org.uk/upload/images/left/adult%20human%20bone%20marrow%20stem%20cell.jpg
Cell Theory
• 1. All living things are made of one or more cells.
• 2. Cells are the basic unit of structure and function in organisms.
• 3. All cells arise from existing cells.
Small cells function more efficiently than large cells
• Small cells can exchange substances more rapidly than large cells because small objects have a higher surface area to volume ratio.
• Substances don’t need to travel as far to reach the center of a small cell.
• Cells must be small as larger cells find it difficult to bring in enough food, and export enough wastes to keep the cell alive.
• As cell size increases, the ratio of cell volume to cell surface area decreases. At some point as cells increase in size, there isn't enough cell membrane to adequately supply the cell interior with enough oxygen, water, and food. When this happens, the cell dies.
http://ghs.gresham.k12.or.us/science/ps/sci/soph/cells/pics/surfvol.jpg
http://library.thinkquest.org/C006669/media/Biol/img/surface_area_to_volume_ratio.gif
Common features of cells
• Cell membrane – encloses the cell, regulates what enters and leaves the cell
• Cytoplasm- interior of a cell
• Cytoskeleton- system of microscopic fibers
• Ribosomes-make proteins
• DNA-instructions for making proteins, regulates cellular activities and reproduction
Prokaryotes
• Smallest and simplest• Single-celled
organism that lacks a nucleus and other organelles.
• Bacteria– Cell wall –provides
structure and support– Flagella- long
threadlike structures used for movement
http://www.prokaryote.com/prokaryote.jpg
http://www.haverford.edu/biology/Courses/bio300/BioGallery00/presentation.llem/EM/SEM%203D%20photo%20of%20E-Coli%20%23A93.jpg
Eukaryotic Cells
• Has a nucleus and membrane bound organelles
• Organelle- structure that carries out specific activities in the cell.
• Cilia and flagella move some cells through their environment.– Cilia-short hairlike
structures
http://bioweb.usc.edu/courses/2001-spring/documents/gifs/eukaryote.gif
Eukaryotic Cells
http://www.pirx.com/droplet/gallery/paramecium/paramecium1.jpg
http://web.ukonline.co.uk/m.hoult/fw/images/amoeba.jpg
http://images.google.com/images?svnum=10&hl=en&lr=&q=white+blood+cell&btnG=Search
Paramecium
White Blood Cell and Bacteria ( a prokaryote)
Plant Cell
http://www.biologie.uni-hamburg.de/b-online/fo04/2vergrzw.jpg
Cell Membrane
• Lipid bilayer• Selectively permeable
http://library.thinkquest.org/C004535/media/cell_membrane.gif
Homework
• Read Chapter 3 Section 2 55-60
Answer Questions 1-5