Transcript Cell Features Presentation

Cell Features
http://personal.tmlp.com/Jimr57/textbook/chap
ter3/images/cell1.jpg
http://www.rdsonline.org.uk/upload/images/left/adu
lt%20human%20bone%20marrow%
20stem%20cell.jpg
http://biology.clc.uc.edu/graphics/taxo
nomy/plants/spermatophyta/angiospe
rms/dicotyledonae/Rutaceae/Gas%20
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.
http://ghs.gresham.k12.or.us/science/p
s/sci/soph/cells/pics/surfvol.jpg
• 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://library.thinkquest.org/C006669/media/Biol/img/surf
ace_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
http://www.prokaryote.com/prokaryote.jpg
– Cell wall –provides
structure and support
– Flagella- long
threadlike structures
used for movement
http://www.haverford.edu/biology/Cours
es/bio300/BioGallery00/presentation.lle
m/EM/SEM%203D%20photo%20of%2
0E-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/2001spring/documents/gifs/eukaryote.gif
Eukaryotic Cells
Paramecium
http://www.pirx.com/droplet/gallery/pa
ramecium/paramecium1.jpg
White Blood Cell
and Bacteria ( a
http://images.google.com/images?svnum=
10&hl=en&lr=&q=white+blood+cell&btnG=
prokaryote)
Search
http://web.ukonline.co.uk/m.hoult/fw/images/amo
eba.jpg
Plant Cell
http://www.biologie.uni-hamburg.de/bonline/fo04/2vergrzw.jpg
Cell Membrane
• Lipid bilayer
• Selectively permeable
http://library.thinkquest.org/C0045
35/media/cell_membrane.gif
Homework
• Read Chapter 3 Section 2 55-60
Answer Questions 1-5