Chapter 4 Flashcards
(31 cards)
What are Achaea best known for
Growth in anaerobic, hypersaline, ph extremes, and high temp habitats
They can live anywhere though
What is pleomorphic
No distinct shape or having a unique shape/arrangement
What are two common shapes for archaea
Cocci and rods
What is the most common cell envelope in archaea and what is it made of
S-layer made of proteins which is different from glycocalyx because that is made of sugars
Archaea don’t really have glycocalyx they have s-layer instead
What are the five membrane set ups known about in archaea
S-layer
S-layer and outer coating on top (sugar or protein)
Protein or sugar on top then the s-layer
Carb or protein layer and no s-layer
Double plasma membrane
What are hydrocarbons derived from
Isoprene units which are five carbon branched molecules
How are hydrocarbons attached to a glycerol in archaea
By an ether rather than an ester
Bacteria are attached by ester
Why is the presence of ringed structures within the plasma membrane important for archaea
Ring structures increase rigidity of the membrane
What is a nucleoid
Region in the cytoplasm that contains circular chromosomes and nucleoid associated proteins (NAPs)
Why is supercoiling and NAPs important in archaea
They assist in folding and in chromosome condensation
What do histones do for archaea
They organize the chromosomes into nucleosomes that are related to those in eukaryotes
True or false: archaea don’t have membrane bound organelles
True they are like prokaryotes
How does dna replication work in archaea
Similar to bacteria
Use dna polymerase and initiation proteins
What is cell division like in archaea
MreB and FtsZ are useful for binary fission as they are cytoskeletal elements
They also have eukaryotic like proteins involved as well
How does transcription work in archaea
DNA strand binds to tata box in the promoter
The promoter is what tells rna polymerase where to start transcription
How does translation work in archaea
Ask Annabelle about slide 12
How does translation work in archaea
Ask Annabelle about slide 12
What is the ribosomal makeup of archaeal ribosomes
70s constructed of 50s and 30s subunits
What is different about the rRNA molecule in archaea vs bacteria
Similar in size but nucleotide sequence is different
How does protein composition differ in archaea ribosomes
They have r-proteins
They are unaffected by antibiotics that target the ribosomes
Archaea are more similar to eukarya than bacteria
What are pili
Made of pilin proteins that are made in the cytoplasm and anchor to a protein complex in the plasma membrane
What is a cannulae
Archaeal pili that is hollow and tubelike on the surface of thermophilic archaea
Give daughter cells that arise from cell division connection to one another
What are hami
Resemble grappling hooks
May work to attach cells to surfaces
Seen in biofilm communities
Are flagella or bacteria thinner?
Flagella
Some are made of more than one type of protein
Filaments are not hollow
