Introduction To Cells

History & Definition  First cells seen where cork cells in 1665 by Robert Hooke.  A cell is the smallest unit that can still carry on all life processes.  Ex. Red blood cells, nerve cells

Cell Theory  All organisms are composed of one or more living cells  The cell is the basic unit of life in all living things.  All cells come from existing cells. (chicken or the egg?)

Cell Similarities  All  Have cell membrane  Contain hereditary material (DNA)  Have Cytoplasm and Ribosomes  Are small in size  Most cannot be seen with naked eye

2 Main Types of Cells  Prokaryotic  Include bacteria  Do NOT have a nucleus  Have long circular DNA  No membrane bound organelles  Contain ribosomes to make proteins.  rod shaped, spherical, and spiral

Prokaryotic Cells: Bacteria  Reproduction: Usually Asexual  Binary Fission: an organism duplicates its DNA and then divides into two parts, with each new organism receiving one copy of DNA.  Conjugation: Exchange of DNA between bacteria (not Asexual)

Prokaryotic Cells: Bacteria  Either classified as eubacteria or archaea.  Eubacteria: commonly found  Archaea: Live in extreme environments

Prokaryotic Cells: Bacteria “The Good”  Bioremediation: organisms are added to water to convert toxic pollutants, such as oil, into harmless substances.  Food Production: Butter, Cheese, Yogurt, Sauerkraut, Beer, Pickles, Olives, Chocolate, Coffee, Soy sauce, meats, etc.  Decompose dead organisms  Digesting food  Fix Nitrogen for Plants

Prokaryotic Cells: Bacteria “The Bad”  Food Spoilage  Can cause disease in plants and animals  Produce Toxins

Prokaryotic Cells: Bacteria “The Ugly”  Must be dealt with every day.  People die each year from infections.  Bubonic Plague:  Killed 2 out of 3 patients in 2-6 days without treatment  Yersina pestis  Anthrax

Prokaryotic Cells: Bacteria  Ways to prevent disease:  Wash hands!!!  Cook food thoroughly.  Keep foods cold.(slows metabolism)  Antibiotics

2 Main Types of Cells  Eukaryotic (YOU!)  More complex & larger than proK  Have membrane bound organelles  Has a nucleus  Has more DNA than proK  DNA is linear  Animal, plant, fungi  NOT BACTERIA

Cell Movement  Flagella: tail-like projections  Pseudopod: false-foot  Cilia: finger-like projections (some non-motile)