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 Ostrich egg

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)