Microbial Cell Structure and Function Flashcards
It deals with the size, shape and arrangement of a living organism
Morphology
The study of the size and shape of the cell
Cell Morphology
What is the approximate size of bacteria?
3 micrometer
What is the size of cocci?
ranging from 0.5 to 3 micrometer
What is the size of bacilli?
ranging from 0.15 to 2 micrometer (width) to 0.5 to 20 micrometer (length)
What are the bacterial shapes? define each one.
Cocci - spherical and ovoid
Bacilli - cylindrical
Spiral - curve or loose spiral
What are the Bacterial arrangements?
Singly - single
Strepto - in chain
Staphylo - in cluster
Diplo - in pairs
Sarcinae - three dimensional cubes
Spirochetes - tightly coiled
What are the three major functions of the cytoplasmic Membrane in prokaryotic cells?
- Barrier preventing the passive leakage of solutes into or out of the cell.
- anchors several proteins that catalyze a suite of key cell functions.
- plays a major role in energy conservation and consumption.
What is the mode of movement of bacteria or microorganisms to transfer any disease?
Vector
What do hydrophobic and hydrophilic mean?
Water-repelling and water-attracting
Strengthened by sterol-like molecules that is present in bacteria
Hopanoids
This strengthens the membranes of eukaryotic cells where there is an absence of cell wall.
Sterols
Take note of this and memorize!
the cytoplasmic membrane of Archaea is structurally similar to those of bacteria and Eukarya, but chemistry is somewhat different.
The layer outside the cytoplasmic membrane; gives shape and rigidity to the cell.
confers structural strength on the cell in order to keep it from bursting due to osmotic pressure
Cell wall
Two major group of Cell Wall
Gram-positive
Gram-negative
This cell wall is thicker and has single type of molecule
Gram-positive
This cell wall consist of two layers
Gram-negative
List the three osmotic pressure and give their definitions
- hypertonic - cell shrinks, H2O goes outward
- Isotonic - balance, H2O goes in and out
- hypotonic - cell bursts, H2O goes inward
weakens the peptidoglycan and causes cell lysis.
acts as a major line of defence against bacteria.
destroys pre-existing peptidoglycan
Lysozyme
Made up of rigid polysaccharides.
not present in archaea and eukarya.
Peptidoglycan
Space located between the outer surface of the cytoplasmic membrane and the inner surface of the outer membrane spans about 15nm
Periplasm
Channels for the entrance and exit of solutes
Porins
Forms water-filled channels through which virtually any very small hydrophilic substance can pass
Non-specific porins
Contain a binding site for one or a group of structurally related substances
Specific porins
cell walls of a certain methane-producing Archaea
Methanogens
is a Latin word for wall and was an old term for peptidoglycan
Murein
