Chapter 1 and 3 Flashcards
- one of the most important groups by any criterion
- Phenomena in biochemistry and
molecular biology comes from
bacterial research
bacteria
shape of bacteria that is chainlike
streptococci
shape of bacteria that is pair
diplococci
shape of cell that is grapelike clusters/ broad sheets
staphylococci
divide in 2 planes and remain in groups of 4
tetrads
divide in 3 planes and remain in cube like groups of 8
sarcinae
Single
DIPLObacilli: pair
STREPTObacilli: chainlike
bacilli
curved rods
vibrios
helical, rigid; uses flagella to move
spirilla
helical, flexible; uses axial filaments to move
spirochetes
Maintain single shape
monomorphic
Many shapes
Individual variation on cell wall
Change in shape may be due to disruption
pleomorphic
Substance that surrounds cells
Sugar coat Viscous, gelatinous polymer composed of polysaccharide or polypeptide
Layer that is often quite thick
Transparent, not easily stained
glycocalyx
Important in contributing to bacterial virulence
Protection from phagocytosis
Attachment to various surfaces
Source of nutrition
Inhibit movement of nutrients
from the cell
Prevent dehydration
glycocalyx
two types of glycocalyx
capsule and slime layer
organized substance
attached to cell wall
capsule
unorganized and
loosely attached
slime layer
- Protect bacterial colonies from
host defenses - Protect the bacteria from toxic
agents - Contributes to the pathogenesis of
bacteria
Biofilm
Long filamentous appendages that
propel bacteria
Filament – outermost, contains the
protein flagellin
Hook
Basal body – anchorage to cell wall
and plasma membrane
Used for motility
Moves the cell by rotating from the
basal body
flagella
outermost, contains the
protein flagellin
filament
anchorage to cell wall
and plasma membrane
basal body
movement of flagella
toward or away from a stimulus
taxis
types of flagella
Monotrichous
Lophotrichous
Amphitrichous
Peritrichous
Another appendages for
movement
Bundles of fibrils that arise at the
ends of the cell beneath the outer
sheath and spiral around the cell
Usually seen in Spirochetes
axial filament
Longer than fimbriae
Rigid tubular structures made of the protein pilin
Pilin can be antigenic
Join cells for the transfer of DNA(conjugation)
Only found in Gram-negative bacteria
Pili
Complex, semi-rigid structure
Responsible for characteristic shape and architecture
Surrounds and protect cytoplasmic membrane and internal parts
cell wall
- for adherence to surfaces
- also called common pili
- example: Neisseria gonorrhoeae
fimbriae
Protects against changes in osmotic pressure
Helps maintain cell shape
Anchorage site of flagella
Contributes to the ability to cause diseases
Site of action of some antibiotics
Used to differentiate major types of bacteria
cell wall
Provides rigidity and flexibility
Present only in
prokaryotes
Polymer consisting of N- acetylglucosamine (NAG) and N-acetylmuramic acid
(NAM)
peptidoglycan
- disruption of membrane
- lost of cytoplasm
- lipoteichoic acid
lysis
- major cell wall component of some archaea
- false cell wall
- acetyl amino acid
pseudomurein
Also present in the cell wall
of gram-negative bacteria;
unique to bacterial cell
wall
diaminopimelic acid (DAP)
Thick layer of
peptidoglycan
Negatively charged
teichoic acid on surface
gram-positive bacteria
Thin peptidoglycan
Outer membrane
Periplasmic space
gram-negative bacteria
Many layers of peptidoglycan
Insoluble but porous
Stain purple in gram stain
Contains teichoic and lipoteichoic acid
Polymers of ribitol orglycerol joined by a
phosphate group
Bind and regulate movement of cations into
and out of the cell
Plays a role in cell growth
Prevents wall breakdown and lysis
gram-positive cell walls
One or few peptidoglycan layers found in the periplasmic space bonded to lipoproteins in the outer membrane
Stains red or pink in gram staining
Periplasmic space–space between outer membrane and inner cell membrane
“Bag of enzymes”: enzyme rich space
Degrades macromolecules Protects against toxic intruders
Gather/bind essential nutrients and deliver to transport proteins
gram-negative cell walls
space between outer membrane and inner cell membrane
periplasmic space
Serves as a selective permeability barrier which prevents slows entry of potentially toxic materials and allows entry of nutrients
porins
Lack walls or may have unusual walls composed of polysaccharides and proteins
archaeobacteria
Naturally have no cell wall
Smallest known bacteria
It has a plasma membrane, which consists of sterols that protect cell form lysis
mycoplasma
- Consists of special lipids and
proteins - Destroyed by alcohols and
polymyxin antibiotics - Thin structure enclosing the
cytoplasm
cell membrane
Irregular folds of the
plasma membrane
Previously described as
artifacts
mesosomes
The organelle of
photosynthesis in
photosynthetic bacteria
chromatophores
Location of most biochemical
activities
Contains DNA, ribosomes, and
inclusions
cytoplasm
- Reserve deposits
- Granules containing nutrients, monomers, Fe compounds(magnetosomes)
inclusions
contains a single, long, circular molecule of double stranded DNA Carry genetic information
bacterial chromosomes
Small, circular. Double stranded DNA molecules
Extrachromosomal genetic material
May carry genes for virulence of the organism
In conjugation, it can function independently from nuclear area
plasmids
Responsible for the granular appearances
Main site of protein synthesis
Composed of 2 sub-units each with a protein and ribosomal RNA
Can be inhibited by certain antibiotics
ribosomes
Form during adverse conditions (Sporulation)
Persist for several years until appropriate stimulation gives rise to singular bacterial cell Resting structures
Highly durable dehydrated cells with thick wall
Can survive extreme heat, lack of water, and exposure to many toxic chemicals and radiation
Special coat surrounding the spore
Relative resistance to antibiotics
endospores
Bacteria and location of spore
Central, terminal, or
subterminal
Process of endospore
formation within a
vegetative cell
sporulation
Return of endospore to a
vegetative state
germination
The process by which coloring
agents or dye is added to the
specimen to enhance microscopic
examination
Acidic dye has negative charge so
they bind to positively charged cell
structures like some proteins
Basic dye have positive charge &
bind to negatively charged
molecules
staining
Crystal violet-iodine crystal form I
cell
gram stain
Alcohol dehydrates
peptidoglycan
CV-I crystal do not leave
gram-positive
Alcohol dissolves outer
membrane and leaves
holes in peptidoglycan
CV-I washes out
gram-negative
Bacteria such as those in the genus
Mycobacterium do not readily
stain but do so upon application of
heat
- Mycolic acid (waxy lipid) covers thin peptidoglycan layer
acid fast stain
Spores are most simply observed as colorless areas in cells stained by conventional methods
The spore wall is relatively impermeable, but dyes can be made to penetrate it by heating the preparation
Spores are commonly stained with malachite green or carbolfuchsin
endospore stain
This procedure involves staining the background with an acidic dye, leaving the cells contrastingly colorless
The black dye nigrosin is commonly used
This method is used for cells or structures that are difficult to stain directly
negative staining
Flagella are too fine to be visible in the light microscope
Treating the cells with an unstable colloidal suspension of tannic acid salts
The apparent diameter of the flagella is increased to such an extent that subsequent staining with basic fuchsin make the flagella visible in the light microscope
flagella stain
______________ are usually demonstrated by the negative staining procedure or a modification of it
involves treatment with hot crystal violet solution followed by a rinsing with copper sulfate solution
capsule/ capsule staining
is a result of the inward
growth of the cytoplasmic
membrane and cell wall from
opposing directions until the two
daughter cells are pinched off
septum
If the cells remain temporarily
attached after division, certain
characteristics groupings result
Depending on the plane of division
and the number of divisions
through which the cells remain
attached
After fission of some bacteria, characteristic post division
movement occur
cell groupings
- tremendous impact on life (physically and chemically)
- unicellular or multicellular
microorganisms
practical outgrowth of science created by blend of technique and theory
prediction
continuing association of different organisms
symbiosis
biologic consequence of natural selection operating on a vast array of genetically diverse organisms
evolution
- they lack cell attributes including ability to replicate virophages
viruses
they can infect their own
virophages
small, single-stranded, covalently closed circular RNA molecules existing a highly base paired rod-like structures
viroids
viruses used it for protection
capsid
a degenerative central nervous system disease of sheep
scrapie
-proteinaceous and infectious nature
- Kuru, CJD, Grestmann and fatal familial insomia affect humans
Prions
this disease are unique in that they manifest as sporadic, genetic, and infectious
human prions
- small size, absence of nuclear membrane
- DNA of almost all bacteria is circle with length about 1 mm
Prokaryotes
region for cell containing DNA
Nucleoid
derived from single cell, physically interconnected
clone
cell-cell communication mechanism, regulate transcription of genes
quorum sensing
- prokaryotes that established symbiosis within the cell
endosymbiotic
lacking of cell wall, nuclei
mycoplasma
specialized cell structures that may allow survival in extreme environments
- useful criteria for classification because well-characterized subsets of bacteria from spores
spores
classification of prokaryotes
spores, algae, protozoa, fungi, slime molds
ameboid cells live and grow by ingesting fungi and bacteria
slime molds
programmed cell death
apoptosis
