UNIT ____:  Prokaryotic Cells                                               Name:  _________________________

Essential Idea(s):

Prokaryotes have a much simpler cell structure than eukaryotes.

IB Assessment Statements and Class Objectives

1.2.U1

Prokaryotes have a simple cell structure without compartmentalization.

  • Outline the major differences between prokaryotic and eukaryotic cells.
  • List the functions of the following structures of a prokaryotic cell:  cell membrane, nucleoid, plasmid, cytoplasm, ribosome, cell wall, pili, capsule, flagella
  • Define extracellular.
  • Contrast the size of eukaryotic and prokaryotic ribosomes.

1.2.S1

 

Drawings of the ultrastructure of prokaryotic cells based on electron micrograph.

  • Explain why the ultrastructure of prokaryotic cells must be based on electron micrographs.
  • Draw the ultrastructure of E.coli, including the cell wall, pili, flagella, plasma membrane, cytoplasm, 70s ribosomes, and nucleoid with naked DNA. 

3.2.U1

Prokaryotes have one chromosome consisting of a circular DNA molecule.

  • Describe the arrangement of prokaryotic DNA (nucleoid and plasmid).
  • Define the term “naked” in relation to prokaryotic DNA.
  • Compare the genetic material of prokaryotes and eukaryotes.

3.2.U2

Some prokaryotes also have plasmids but eukaryotes do not.    

  • Describe the structure and function of plasmid DNA

1.2.U3

Prokaryotes divide by binary fission.

  • Define asexual reproduction and binary fission.
  • Outline the steps of binary fission.

6.3.U7

Antibiotic blocks processes that occur in prokaryotic cells but not in eukaryotic cells.

  • Define antibiotic.
  • Outline the mechanisms by which antibiotics kill bacteria.

6.3.A3

Florey and Chain’s experiments to test penicillin on bacterial infections in mice.

  • Explain methods and results of Florey and Chain’s experiments.

6.3.NOS

Risks associated with scientific research- Florey and Chain’s tests on the safety of penicillin would not be compliant with current protocol on testing.

  • Compare allowable research risks of the past with those of the present.

6.3.U8

Viruses lack a metabolism and cannot therefore be treated with antibiotics.

  • Explain why antibiotics are ineffective against viruses.

1.2.U1

Prokaryotes have a simple cell structure without compartmentalization

List the functions of the following structures of a prokaryotic cell:

Define “extracellular.”

Highlight the extracellular structures of a prokaryotic cell.

1.2.S1

Drawings of the ultrastructure of prokaryotic cells based on electron micrographs

Explain why the ultrastructure of prokaryotic cells must be based on electron micrographs.

Draw the ultrastructure of E. coli based on an electron micrograph.

The line segment corresponds to 0.5 μm

3.2.U1 / 3.2.U2

Prokaryotes have one chromosome consisting of a circular DNA molecule

Some prokaryotes have plasmids but eukaryotes do not

Nucleoid

Describe the structure and function of nucleoid DNA

Plasmid

Describe the structure and function of plasmid DNA

Define “naked” in relation to prokaryotic DNA:

Compare the genetic material of prokaryotes and eukaryotes:

PROKARYOTIC DNA

EUKARYOTIC DNA

1.2.U3

Prokaryotes divide by binary fission

Define asexual reproduction and binary fission.

Outline the steps of binary fission.

Prokaryote Metabolism        

①

All cells must acquire energy and carbon in order to synthesize organic compounds for use by the organism (lipids, nucleic acids, proteins and carbohydrates).  Prokaryotes are grouped into four categories according to how they obtain energy and carbon:

TYPE OF METABOLISM

ENERGY SOURCE

CARBON SOURCE

EXAMPLE

Bacteria that live in the human body (for example E. coli) and all disease causing bacteria.

Nitrifying bacteria use nitrogen from the air as their energy source (for example azotobacter)

Rare now, but may have been some of the first life on Earth.  Mostly marine prokaryotes that make up plankton.

Cyanobacteria live in freshwater, seas, soil and lichen, and use a plant-like photosynthesis which releases oxygen as a by-product.

Great Oxidation Event

②

Prokaryotic cells have differing oxygen requirements.  Oxygen is needed for cellular respiration. 

③

Prokaryotic cells have vital roles in a functioning ecosystem. 

  • _______________

As "primary producers" the cyanobacteria are the basis of the food chain in marine environments. In addition, their type of photosynthesis generates a substantial amount of oxygen in the earth's atmosphere.   Cyanobacteria carried out photosynthesis for at least a billion and a half years before the emergence of plants.

  • _______________

As saprotrophs, many chemoheterotrophic prokaryotes are extremely important in the overall functioning of ecosystems. They are involved in breaking down a wide variety of organic materials of both natural and human made origin. The process of decomposition is an important one as it is the main mechanism whereby inorganic nutrients, such as nitrogen and phosphorus, can be released to be used again by primary producers.  The ability of bacteria to degrade a variety of organic pollutants, such as oil, is also significant.  

  • _______________ in the _______________

6.3.A3

Florey and Chain’s experiments to test penicillin on bacterial infections in mice.

Florey and Chain were the scientists who followed up most successfully on Alexander Fleming’s discovery of penicillin.  Annotate the diagram of one of their experiments to test the effect of penicillin on treating a bacterial infection.

6.3.NOS

Risks associated with scientific research- Florey and Chain’s tests on the safety of penicillin would not be compliant with current protocol on testing

Florey followed up the mice experiments with additional testing on more mice and in sick humans.

Summarize the first human test of antibiotics:

Compare allowable research risks of the past with those of the present.

Past

Present

  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  

6.3.U8

Viruses lack a metabolism and cannot therefore be treated with antibiotics.

Explain why antibiotics are ineffective against viruses:

6.3.U7

Antibiotics block processes that occur in prokaryotic cells but not in eukaryotic cells

Define antibiotic:

Outline the mechanism by which antibiotics kill bacteria:

Read the information at the following two websites and annotate the notes with 1) the name of one example antibiotic for each type of antibiotic action and 2) a brief summary of why each antibiotic class effects prokaryotic cells but not eukaryotic cells.