3. Archaea and Eukaryotes: Medical Micro

Archaea and Eukarya Commonalities with all cellular life?

• DNA

• Ribosomes

• Membrane

• Central Metabolism

What sets Archaea apart from them?

• Exists in extreme environments

• Lipid membrane is structurally different

• Methanogenesis

• Cell boundary layers: cell membrane, s-layer

Archaea membrane difference vs bacteria

Archaea:

fatty acid chain have additional branches

may have a lipid membrane that connects all the way instead of a bilayer

Glycerol diethers form lipid bilayers: glycerol tetraethers form lipid monolayers

Bacteria:

Ester-linked phospholipids and hopanoids form a lipid bil-layer

Archaea cell wall vs Bacteria cell wall

Archaea - cell wall is called “s-layer.”

• Made up of proteins or glycoproteins

• Contains a polymer called pseudomurein

Bacteria cell wall is made up of peptidoglycan

What are methanogens? What is anaerobic?

Methanogens - bacteria that produce methane

Anaerobic - no oxygen

Additional Archaeal structures?

Archaellum

Cannulae

Hami

Archaellum function vs Flagella function: Differences and similarities

Archaellum and Flagella similarities:

• Promote movement through the environment

• utilize an ion gradient to initiate rotation

Differences:

Archaellum: Solid Structure while flagella is hollow

Archaellum has different subunits while flagella has the same

Archaellum has a less defined hook while flagella has a defined hook

Archaellum will cause a forward and reverse in direction while flagella will cause a tumble when rotating clockwise

Cannulae?

Hollow structure

Unknown function

Grow with cell divison

Aid in production of multicellularity

Hami

Long filaments that has hooks at the end

Biofilm and adhesion formation

Fairly heat stable

Plant cell wall is made up of?

• Cellulose (made up of chains of glucose)

Another type of “cell wall” in the eukaryotic domain?

Fungal cell wall: made up of chitin (main exoskeleton of bugs)

Bacteria vs Eukaryote DNA structure

Bacterial DNA:

• circular DNA

• Single chromosome

Eukaryotic DNA:

• Linear

• Multiple chromosomes

Eukaryotes Cilia?

Beats back and forth to promote movement

Cellular reproduction of the 3 domains?

Bacteria and Archaea:

• Binary fission: asexual reproduction

Eukaryotes:

• Mitosis: Chromosomal replication and cell replication

• Meiosis: Sexual reproduction

Endosymbiosis meaning? What are some evidence proving this?

• Mutually beneficial relationship between two organism where one lives inside the other

Evidence:

1. Plastids and mitochondria contain circular DNA without histones

2. Bacterial-type RNA polymerase involved in organelle transcription

3. 70s Ribosomes

4. Division by binary fission inside the cell

5. 16S rRNA sequence homolgy roots each in particular group of GM - Bacteria

6. (Mito with aplha-proteobacteria and plastids with cyanobacteria)

Size of DNA molecules in mitochondria and plastids are smaller than free living bacteria due to Genome Reduction. Why?

Many genes were not required any longer within the calm cytoplasm.

How can we treat Malaria?

We target the plastid

80s vs 70s ribosomes

70s is bacterial while 80s is eukaryotes

16s rRNA vs 18s rRNA

16s is bacteria while 18s is eukaryote