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.
