Prokaryotic and Eukaryotic Cells Two types of cells Prokaryotic and Eukaryotic Cells

What is a cell? It took a long time for people to discover cells and figure out what they were all about. They need sophisticated equipment (microscopes) to be able to see cells. Everything we know about cells we call “cell theory”

Cells come in all shapes and sizes!

Cells – the Reason they are small… Cell size is limited. -As cell size increases, it takes longer for material to move from the outside to the inside of the cell and vice versa *Cells need to have high Surface Area -to- volume ratio which means it has to have more area on the outside than on the inside to take in food and get rid of wastes

There are 2 types of cells: Prokaryotes Eukaryotes True Bacteria Archaea-Bacteria Animal Plant

Prokaryotic Cells

Prokaryotic Cells: A prokaryotic organism is a single celled organism (unicellular) that does not have a nucleus. Examples of Prokaryotic organisms are: True Bacteria Archaea-bacteria

Traits of prokaryotes All bacteria cells are prokaryotes. They do NOT have a nucleus Their genetic material (DNA) is located in the Nucleoid region. They do NOT have membrane-bound organelles. They are less complicated than eukaryotes. All bacteria cells are prokaryotes.

Prokaryotic Cell Diagram

Prokaryotic Cell Parts: _______________ do not have a membrane-bound ______________. - the genetic material (_________) is in the _____________region Prokaryotic Cells Nucleus DNA Nucleiod

Prokaryotic Cell Parts: Prokaryotic cell walls Protects the cell Helps the cell keep its shape

Prokaryotic Cell Parts Flagella (pl.) or Flagellum (sing.) long, tail-like structure used for movement

Prokaryotic Cell Parts: Ribosomes the place where protein is made Usually found floating in the cytoplasm

Shapes of Prokaryotes Spirillum – spiral shaped Coccus or Cocci (pl.) – circular or sphere like Bacillus – rod or pill shaped

We need bacteria to live! Bacteria are decomposers and without them all other organisms would not be able to survive. We use bacteria in our digestive system to help digest our food. There are approximately ten times as many bacterial cells as human cells in the human body! We could not make cheese or yogurt or many other foods without bacteria.