Exam 4 Material

microorganisms

any organism too small to be observed by the unaided eye

organelle

membrane bound structure with specialized function in cell

bacterial cell wall

peptidoglycan

archaea cell well

pseudopeptidoglycan

cocci

spherical

bacilli

rod shaped

peptidoglycan

polysaccharide chains joined by amino acids

extracellular polysaccharides (EPS)

extra, non-essential layers beyond the peptidoglycan or outer membrane

pili

rigid spiky protein fiber appendages involved in adhesion, motility, or genetic transfer

flagella

massive protein structures involved in motility

S-layer protein shell

crystalline shell of glycoproteins (proteins decorated w/ sugars

very common in archaea

provides structural integrity

archaea cell wall

pseudopeptidoglycan

hyperthermothiles

live and grow at high temp

halophiles

salt/solute tolerant organisms

methanogens

generate _ gas as waste products

Reduce CO₂ to CH₄

binary fission

symmetrical division of a parent/mother cell into 2 identical daughter cells

horizontal gene transfer

transfer of one/a few genes from one bacterial cell to another

transformation

uptake of free DNA directly from the environment “com machinery”

conjugation

export of DNA from one cell to another “Tra machinery”

transduction

transfer of genetic material between 2 bacteria by means of a bacteriophage

generalized transduction

mispackaged bacterial DNA can come from ANY location on the bacterial chromosome

specialized transduction

mispackaged bacterial DNA can ONLY come from the part of the bacterial chromosome that is ADJACENT to the prophage integration site

bacteriophage

tiny viruses that infect bacteria

-little more than copies of genetic material surrounded by capsid (protein coat)

obligate parasites

use host to make copies of themselves

-lack ribosomes and cannot make their own energy

viruses reproduce by:

lytic cycle and lysogenic cycle

lytic cycle

viruses infect host immediately start to make viral copies and then kill host cell

lysogenic cycle

when phages infect bacteria but do not proceed to lysis

mutualism

(+/+)

probiotics

live microbial cultures applied to or ingested that are intended to be beneficialmi

microbial antagonism

form of competitive exclusion: existing normal microflora prevents a disease causing microbe from colonizing and causing disease by competing with it for vital resources in your body

commensalism

(+/o)

parisitism

(+/-)

pathogens infect body and kill our cells, pathogen grows and we’re harmed

takes nutrients away from other cells

biofilms

non-essential bacteria cell aggregates held together by EPS sugars

heterocysts

specialized, differentiated, non-growing, O₂ impermeable cell types found in cyanobacteria

does nitrogen fixation and shares nutrients back and forth between cells

stromatolites

ancient, fossilized microbial mats (biofilms)

mixotrophs

combination of photoautotrophic and heterotrophic nutrition

multiple fission

nucleus of parent cell divides several times by mitosis, producing several nuclei

the cytoplasm then separates, creating multiple daughter cells

conjugation

sexual reproduction when opposite mating strains join and exchange genetic material

polyphyletic grouping

grouping that does not include all descendants of a common ancestor

cilia

hairlike membrane/microtubule projections used for movement and food capture

foramniferans and radiolarians

shell-like glass or calcium carbonate structures

thin threadlike pseudopodia radiating outwards

gymnamoebas and entamoebas

no shell and have lobe- or tube-shaped pseudopodia (rather than threadlike)

include free-living heterotrophs and some parasites

pseudopodia

extension of plasma membrane driven by actin filaments, used for movement and feeding

primary endosymbiosis

protists gained chloroplast through symbiosis of a cyanobacterium

secondary endosymbiosis

eularyote engulfed red/green algae and became a plastid

multinucleated supercell

multiple nuclei inside a shared cytoplasmic mass

extracellular digestion

secretion of digestive enzymes to environment, break large compounds down into small ones capable of being transported into cell

yeasts

general grouping of unicellular fungi

hypha

filamentous grouping/chain of fungal cells

mycelium

many hyphae organize together into a mass

septate hyphae

cells divided by division like a cell wall, distinct walls with small pore in septum for nutrients and communication

coenocytic hyphae

filament with a shared cytoplasm that is multinucleated

haustoria

modified version of hyphal filament, like a collar/trap specialized for capturing prey

mycorrhizae

mutualism between fungi and roots of plants

ectomycorrhizal fungi

sheaths of hyphae over a root and grow onto root surface

arbuscular mycorrhizal fungi

extend hyphae through the cell walls of root cells and into tubes formed by invagination of root cell membrane

dikaryotic

two nuclei per cell