Test 1(CH3) Flashcards
two most common shapes of Bacteria
Cocci and rods
-cocci are circles
-rods are like small spaghettis
Cell wall of gram-positive bacteria is consist of a single ________ layer of _____
20-80 nm thick layer of peptidoglycan (murein)
Cell wall of a gram-negative bacteria has 2 layers: _____ & ________
2-7nm peptidoglycan layer & covered by 12-14 nm thick outer membrane
space between plasma membrane and the outer membrane is called ______
periplasmic space
Feature of all bacterial cells on their cell wall is _________, also called as _________
peptidoglycan , as peptidoglycan sacculus
2 different cross-links structure of a petidoglycan sacculus
Direct & indirect
Direct crossed0link P sacculus is _____
connection of a carboxyl group of an amino acid in one stem petide to the amino group of an amino acid in another stem peptide
Most bacteria that stain gram-positive belong to only 2 phyla, _____ & ______
Antinobacteria & firmicutes
Most of gram positive’s cell wall bacteria are composed of
Peptidoglycan and teichoic acids
Teichoic acids functions:
help creat & maintain the structure of the cell envelope by “anchoring the wall to the plasma membrane “
gram negative cells walls on a bacteria has additional layers (Tor F)
T since the peptidoglycan on negative cell wall are very thin because it is also contains an outer membrane. (this outer membrane is also special because _______)
the structure of the outer membrane of the the gram negative is special because
the external layer (facing the environment) is comprised of LIPOPOLYSACCHARIDES. while the inner layer (facing the cell) contains phospholipids
Lipopolysaccharides’ (LPS) structure contains Lipid A , inner core, outer core, O-antigen
Lipid A contains 2 glucosamine sugar derivatives (with fatty acids & phosphate attached). Lipid A is responsible for the hydrophobic component
LPS Lipopolysaccharides function
(1) contributes to the negative charge on bacteria’s surface since the core polysaccharide contains charged sugars and phosphate
(2)stabilize lipid A
(3) helps create a permeability barrier
(4) protects from pathogenic bacteria (because of O-antigen)
(5) Lipid A portion of LPS can act as a toxin and is called Endotoxin
A class of protein called ______ that helps move solutes through the pol outermsmbrane of a negative gram cell wall is
is Porin
A process called plasmolysis is
bacteria is in hypertonic solution (less water outside cell) water flows out and cytoplasms shrivels up.
If bacteria is in hypertonic soulution
Plasmolysis process will occur and cytoplasm chrivels
Lysis is the process
when cel membrane breaks from having too much water going in
Treatment of a typical gram positive bacteria with _____ & _____ will result into a complete loss of cell wall. the cell wall will become _______
Lysosome & penicillin. it will become protoplast.
Treatment on a negative gram bacteria with ____ & ______. the Peptidoglycan sacculus will be destroyed and will be called _______
Lysosome or penicillin. and will become Spheroplast.
Extracellular Vesicle function (that tiny bulge or storage like on the side of the bacteria)
Transfer toxin molecules during infection, transfer genetic material between cells. they carry some ATP
Bacteria has a surface covering called ______ , & what is it made of ?
S- Slayer, made of protein like glycoprotein.
S- layers has some other functions like
Protecting the cell against ion & pH fluctuations, osmotic stress, enzymes, or predatory bacteria
It also gives adhesion to surfaces and maintain shape.
Why are S-layers important in nanotechnology?
it is because of their ability to self-assemble into an S-layer without any aid.
Protoplast is ________ and _____
The plasma membrane and everything inside it
Pilis are responsible for attachment into another cell or to solid surfaces & can only be seen by
Electron microscope
Type IV pili are involved in _______
motility and two gene transfer mechanism: bacterials transformation & bacterial conjugation
Bacteria has around ____ sex pili. They are ___ to other pili
10 sex pilis, larger to other pilis
Bacterial Flagella function
Motility
Monotrichous bacteria has
only 1 fragellum
Amphitrichous has
2 flagellum on both side
Lophotrichous bacteria
has a cluster of flagellum on either side of the bacteria
Bacteria flagellum is composed of 3 parts :
(1) filament (longest portion)
(2)basal body embedded in the cell envelope
Bacteria flagellum is composed of 3 parts :
(1) filament (longest portion)
(2)basal body embedded in the cell envelope
(3) hook- link the filament to its basal body and act as a flexible coupling
Gram negative bacteria have _ rings connected to a central rod of the flagellum
4 rings : L, P, MS, and C.
the L, P, MS are embedded in the lipopolysaccharide, peptidoglycan, and plasma membrane, respectively and the C ring on the cytoplasmic side of the MS ring
Gram positive bacteria only have 2 rings
inner ring connected to the plasma membrane, and outer one attached to the peptidoglycan
How does filament grow as a flagellum grow on it’s normal size,
it starts growing from the base and then grows more on the very tip. filament synthesis are self-assembly
Bacteria’s movement toward or away chemical stuff is known as
chemotaxis
Motile bacteria move in response to environmental cues such as temperature ______, light _____, oxygen ______, osmotic ______ , and magnetic field ________
thermotaxis, phototaxis, aurotaxis, osmotaxis, magnetotaxis
how does bacteria move its flagellum to move
counter clockwise to run forward & clockwise to tumble
Endospore
dormant cells formed within mother cells, and produced by the phylum Firmicutes
What is sporulation
is when bacterial growth slows down due to nutrient limitation (common on soil bacteria)
2 main size of bacteria
Cocci, rods
less commons ones are
vibrios (comma shaped), spirilla ( rigid spiral-shaped bacteria), spirochetes ( flexible &spiral-shaped bacteria), pleomorphic (lacking a characteristic form)
Actinobacteria form long filaments called _____ and then this form a network called a
hyphae , mycelium
Why are bacteria so small?
Because o greater surface area to volume ratio
what do you call around the cell membrane, capsule, and cell wall of the bacteria?
cell envelope
extracellular layers of a bacterial cell according to their relationships. (Capsule - slime layer, S-Layer )
Capsule organize sugar level , Slime layer disorganize sugar level, and S-Layer organize protein layers
A bacteria that has single flagella
Monotrichious
2 flagellas at the opposing side
Amphitrichous
A bunch of flagellas on either end of the bacteria
Liphotrichous
Bacteria that has ba bunch of flagellas all over their cell membrane
peritrichous
