Ch 27 - Bacteria and Archaea

chitin

a polysaccharide, consisting of amino sugar monomers found in the cell walls of fungi and the exoskeletons of insects, crabs, and other anthropods

cellulose

a carbohydrate made of many glucose molecules joined together to create the cell walls of plants and algae providing strength and support

peptidoglycan

a chain of sugar with protein that forms the cell wall of bacteria, providing structure

fimbriae

short, hair-like structures on the surface of some prokaryotes, which help bacteria to attach to substrate/host or to other surfaces or cells

Gram-negative

bacteria with an outer membrane with less peptidoglycan, safranin stain outer membrane pink/red and is often more toxic than gram-positive bacteria

Gram-positive

bacteria with a simple cell wall with a lot of peptidoglycen, crystal violet stain this layer purple/blue and are usually less toxic than gram-negative bacteria.

nucleoid

a non-membrane enclosed region in a prokaryotic cell where its circular chromosome is naked in

Endospore/s

Thick-coated, resistant cells produced by some prokaryote for protection against harsh condition and remains dormant until conditions improve. Can germinate and return to an active bacterial cell

binary fission

asexual rapid reproduction where the prokaryotes copies its DNA and then divides into two genetically similar cells

Horizontal Gene transfer

the movement of genetic information between organisms without reproduction from parent to offspring

R plasmids

a plasmid that carries genes that can provide resistance to antibiotics (R stands for resistance)

F plasmid

a plasmid that allow bacteria to partake in conjugation and transfer DNA to another bacteria (F stands for fertility)

Photoautotrophs

organisms that uses light as their energy source and carbon dioxide as their carbon sources to make their own food (ex. cyano bacteria)

Chemoautotroph

organisms that uses chemicals to make food by oxidizing inorganic substances

Chemoheterotroph

organisms that can not make their own food and obtain energy and carbon from feeding on other organisms, dead or alive

Obligate aerobes

Organisms that require oxygen for cellular respiration and cannot live without it.

Obligate anaerobes

Organisms that can not survive or grow in the presence of oxygen because it is harmful to them

Facultative anaerobes

organisms that can grow with or without oxygen, but prefers oxygen

Heterocyst

Specialized cells that carries out nitrogen fixation, convert N2(g) to nitrates/nitrites

Extreme halophiles

prokaryotes, specifically certain archaea that thrive in high salt environments

Extreme thermophiles

prokaryotes that thrive in extremely hot/ high temperature environments

methanogens

anaerobic archaea that use carbon dioxide and release methane gas, found in swamps and marshes

Gut bacteria like E. coli, lactic acid bacteria and bifidobacteria

examples of beneficial prokaryotes

vibrio chloerae, chlamydia, and borrelia burgdoferi

examples of pathogenic prokaryotes

endotoxin from prokaryotes

release harmful chemicals when cells are damaged or dies

exotoxin from prokaryotes

proteins that produce and secrete harmful chemicals by the bacterial cell

transformation

a prokaryotic cell takes up foreign, free DNA from its environment and incorporates it into its own DNA

transduction

DNA is transferred from bacteria to bacteria by a virus called a bacteriophage

conjugation

plasmid DNA is transferred bacteria to bacteria through cell to cell contact involving a sex pili plamids

prokaryote cell wall

a rigid layer outside the cell membrane that maintains the cell’s shape and protects it to prevent it from bursting in hypotonic solution

sex pili

longer, specialized pili used in conjugation, they connect a bacteria to another cell and help transfer DNA and do an exchange, often an F plasmid

crystal violet

the first stain used in Gram staining, initially making both Gram-positive and Gram-negative bacteria purple

safranin

the counterstain used in Gram staining that makes bacteria that lost the crystal violet stain appear pink

prokaryote capsule

a sticky outer layer found outside the cell wall that helps with protection and can help bacteria attach to surfaces and avoid being destroyed by host defenses

prokaryote flagella

long, whip-like structures that is bigger than fimbriae and sex pili and used for movement and allow chemotaxis. they allow bacteria to move toward favorable conditions or away from unfavorable ones. Components include: motor, hook, and filament

cocci

round shape bacteria

bacilli

rod-shaped bacteria

spirilla

spirial shaped bacteria