Lecture 8- Prokaryotes

What is meant by a prokaryotic cell?

Bacteria and Archaea cells 

What are the key differences and similarities between Eukaryotic cells and Prokaryotic 

Eukaryotic cells contain membrane bound organelles and a nucleus 

Prokaryotic cells DO NOT contain membrane bound organelles and it packages its DNA in a nucleoid  

What is the theory of the endosymbiotic origin of the eukaryotic cell  

That Eukaryotic cells evolved from prokaryotic cells, when a larger host cell engulfed prokaryotic cells which survived became mitochondria and chloroplasts. 

What are the key features of a bacterial cell. 

• Cell wall- containing peptidoglycan (important in Gram staining) 

• Contains no internal membrane bound organelles 

• Contains circular genomes and usually containing singular chromosome 

Describe the structure of a typical bacterial cell. 

• Cell wall (containing peptidoglycan) 

• Some bacteria contains a flagella 

• DNA is NOT in a membrane bound organelle called the nucleoid 

Explain the difference between the gram positive and gram negative cell wall 

Differs primarily in cell wall structure: 

Gram Positive- Peptiglycodan layer is sitting outside of the outer membrane, which causes it to retain crystal violet 

Gram Negative- Peptiglycodan layer is in between outer membranes so it doesn't retain crystal violet 

How do bacteria move?  

Flagellum- powered by Proton Motive Force

Why are bacteria useful model organisms?  

They are less complex compared to Eukaryotes and they have rapid reproduction rates.

What can we learn from a very simple bacterial growth experiment? 

To understand possible growth curve and distinct phases 

What good and bad things do bacteria do in relation to human health 

Good 

• Aids in gut digestion 

• Produces essential vitamins 

• Fighting off harmful bacteria 

Bad 

• Causes infection and illness 

• Produce toxins 

• Contribute to chronic diseases