MCB 2610: Exam 3 Study Materials - Part 5

archaea used to be lumped in with?

prokaryotic cells

archaeons look like bacteria but genetic analyses show them to be different - they live in some of the most __ places on Earth

inhospitable

Comparisons of rRNA gene sequences can establish?

phylogenetic trees

the first portion termed archaeons were the?

methanogens

size of archaea?

0.5-5 um

archaea has similar shapes to bacteria which can be?

cocci, rods, spheres, spirals, irregular shapes and rectangular shapes

rods sometimes form?

chains

cocci can form?

clusters

can you find rectangular shapes in bacteria or eukaryotes?

no

irregular shapes = ?

pleomorphic

rectangular shape has increased SA:V ratio meaning it can?

take up more nutrients and move more out

DNA organization in archaea?

singular circular chromosome

do archaea have a membrane bound nucleus?

no they have a nucleoid region where DNA hangs out

archaea structure - eukaryal; archaeal DNA is complexed with?

histones

archaea structure - eukaryal; archaea have homologues of?

DNA replication enzymes/transcription and translation machinery

what are distinct archaeal features?

its plasma membrane (organization and composition) and cell wall (composition)

do all archaeons have a plasma membrane?

yes

do all archaeons have a cell wall?

no but most do

the plasma membrane in archaea is always bilayer?

no they can be monolayer

plasma membrane in the phospholipids the hydrocarbons differ how?

they are made up of isoprenes

why is an ether linkage in archaea instead of ester?

ether is thought to be more heat tolerant

isoprenes always have branching and when we pack hydrocarbon tails we always have?

double branch

difference between bi-layer membrane and monolayer membrane

bi layer membrane are not attached to each other at the end while monolayer is completely linked from phosphate to phosphate

what kind of philes more than likely have monolayer

hyperthermophiles

can you do gram stain in archaea?

yes but it won't tell you anything because there's no peptidoglycan in the cell

archaeal cell wall is diverse and has 5 configurations but which layer is the most common?

s-layer

do all archaeal cell walls have s-layers?

no

archaeal cell walls can undergo all?

transports

the cell wall provides?

physical and osmotic protection

pseudomurein

looks like peptidoglycan

is transpeptidase present?

yes but it doesn't work the same b/c there's no d-ala d-ala

amino acids are in what form?

L form

instead of there being NAM it's __

NAM

will lysozyme work against archaea? why or why not?

no because of the beta 1,3 linkage, but lysozyme looks for B-1,4 configuration

will beta-lactam antibiotic work against archaea?

no because b-lactam has the ring structure of d-ala d-ala

will you find inclusion bodies in archaea cytoplasm?

yes but only storage ones not microcompartments

what will you find in archaea cytoplasm?

plasmids, ribosomes, nucleoid and cytoskeleton elements

archaeal nucleosome

smaller but bigger genome size requiring more packing

cytoplasm histones in archaea form structures that?

DNA wraps around and it's different from eukarya

Ta0583 is an actin homolog in Thermoplasma acidophilum that resembles

eukaryal actin

Cytoskeletal proteins from M. thermoautotrophicum and M. kandleri more closely resemble bacterial?

cytoskeletal proteins

what is the only layer that you have in archaea?

s-layer (surface array layer)

cannulae are only found in?

archaea

cannulae are hollow glycoprotein tubes that?

link cells together to form a complex network

what do we think cannulae might allow for?

nutrient sharing and efficient communication

will all archaea have hami?

no

hami are appendages of?

attachment

not all bacteria will have hamit but those that do can usually form?

a biofilm

hami are long helical tubes with?

3 hooks at the end

flagella in archaea are called?

archaella and they are also appendages of locomotion

how are archaella similar to bacteria?

they can rotate to move the cell

are archaella different from bacteria because they are?

thinner and not hollow and are usually composed of two or more different versions of flagellin protein, they also likely are growing from BASE rather from TIP

archaella and flagella are formed independently (conversion evolution) but have the?

same function

archaea can go backwards unlike bacteria and gain energy how?

hydrolyze ATP for movement

clockwise movement is?

forward

counterclockwise movement is?

backwards

archaeal cell structure can undergo?

photo and chemotaxis because they are highly conserved