1110 Lab 4 - Cell Structure and Plasma Membrane Function

Prokaryotic Cells

Prokarytoic means "before kernal" which is to say they don't have a membrane bound nucleus or other organelles. They are generally much smaller than eukaryotic cells. You should know the three common shapes:

• Cocci - round
• Bicilli - rod
• Spirilla - spiral

There are other odd shapes as well. Two of the three domains of life - Bacteria and Archaea are prokaryotes. Anywhere life exists, you'll find prokaryotes there. They are also extremely biochemically diverse. They just don't look like much under the microscope.

scanning EM of soil bacterium Pseudomonas (a bacillus)	group A streptococcus bacteria (a coccus)

Eukaryotic Cells

Eukaryotes (true kernel) are the third domain. They contain a membrane bound nucleus and other organelles such as mitochondria, endoplasmic reticulum, and golgi. Plants contain additional cell structures, relative to animal cells, including chlorplasts, central vacuoles, and a cell wall.

scanning EM of blood cells	Fibroblasts

Osmosis

From PSTCC's Official Practical Review

• Be able to define the following terms: solute, solvent, diffusion, osmosis, isotonic, hypertonic, hypotonic
• Know differences in prokaryotic and eukaryotic cells.
• Be able to identify the three primary shapes of bacteria under the microscope.
• Be able to recognize and identify differences in plant and animal cells.
• Be able to recognize a typical plant or animal cell under the microscope.
• Be able to identify elodea cells in hypertonic and hypotonic solutions.
• Be able to identify red blood cells in hypertonic and isotonic solutions.
• Know what happens to red blood cells that have been placed in a hypotonic solution?
• How and why do plant cells respond differently than animal cells to hypotonic solutions?