Morphology And Structure Flashcards
Size of bacteria
Diameter 0.2-2.0 nanometers
Length 2-8 nanometers
Bacteria measured by
Ocular micrometer
Cocci
In cluster, pairs, chains or packets
Bacilli
Pairs, chains, palisade, rosette
Spirilla
Individual cells with variation in length and spirals
Flagella originate in—– and protrude through the ……..
Made of …..
Cytoplasmic membrane
Cell wall
Flagellin protein
Flagellation is more commonly found on
Baciili
Monotrichous
On flagella on either end of the bacterium
Lophotrichous
Bundle of flagella on either end of the bacterium
Amphitrichous
Flagella on both ends of the bacterium
Peritrichouse
Flagella around the bacterium
Flagella are detected by
Flagella stain directly
Observable motility in wet mounts and hanging drops
True motility
Direction and purposeful movement
Pili (fimbrae) are composed of….. and originate in…..and protrude….
Protein
Cytoplasmic membrane
Cell wall
Pili found on
Gram negative bacteria mostly
Pili are observable on
Electron microscope
Pili are present on both …. bacteria
Motile and no motile
Function of pili
Allows for attachment and adherence,
Used in conjugation
Capsule or slime layer function
Viscous covering of polysaccharides or protein used for protection
Sheath
Tubule enclosing individuals bacteria and are aligned End to end
Stalk
Semi rigid appendages often with adhesive substance at distal end found in some inhabitants of fresh water
Cell wall
Gives shape and is essential for growth and division
All bacteria have them except for mycoplasms
Cell wall protects against
Osmotic lysis
Gram negative have outer membrane composed of
Lipopolysaccharides, phospholipids and lipoproteins
Gram positive bacteria have
Teichoic acid in cell wall
Difference in flagella basal body in gram positive and negative
Positive - 2 rings in basal body
Negative - four rings
Only structure of motility in bacteria
Flagella
Why is a gram stain able to differentiate between gram positive and negative bacteria?
When alcohol is placed on gram positive bacteria, the crystal violet, iodine complex is retained because it cannot pass through the multiple layers of peptidoglycan. However, when alcohol is placed on a gram negative bacterium, lipids are extracted from the outer membrane and the crystal violet iodine complex passes through the thin layer of peptidoglycan.
Treating bacteria with enzyme lysozyme
Removes cell wall creating a protoplast. It will stain gram negative even if it is positive because it cannot hold stain
Endospores are characterized by
LOCATION and size
Bacillis endospore cells are
Not usually swollen
Clostridium endospore cells appear
Swollen
Endospore locations
Terminal, subterminal and central
Sporogenisis
Formation of endospore
Endospore
Dormant, dehydrated structure containing calcium dipocolinate and surrounded by numerous layers (spore cortex + spore coat)
F+ bacteria have a
Sex factor or F factor
F+ has plasmid which allows
for formation of sex pilis- allows for conjugation
HFR cell
High frequency recombination
Will not produce a F+ cell, but passes on some DNA thru
Product of HFR and a F- cell
F- cell with recombinant DNA
Outer membrane of gram negative contains…..
The…. acts as an endotoxin and the …… as an antigenic structure
Lipopolysaccharide
Lipid A
Polysaccharide O
Protein synthesis occurs in the …..
Cytoplasm and mitochondria
Cell wall of eukaryotes is…. compared to prokaryotes
Less complex
Bacteria that don’t have cell Wall are called
Mycoplasmas
Photosynthetic bacteria contain….. and carry on….. if they are Photosynthetic
Bacteriochlorophyll
Anaerobic photosynthesis
Archaebacteria cell wall contains
Murein
Glycocalyx capsule or slime layer function
PROTECTION from phagocytosis
ADHERENCE to surfaces
PROTECTION against desiccation
Possible food reserve
Inclusions
Reserve deposits that can be found in some bacteria
Ex… metachromatic granules
Gas vacuoles
Inclusions of gas that allow buoyancy
Bacterial nucleoid
Genetic material in single chromosome
Bacterial chromosome
Circular molecule of double stranded DNA
PERIPLASMIC space
Space between outer membrane and the cell membrane of gram negative bacteria
Contains hydrolytic enzymes and binding proteins
Bacteria RIBOSOMES
80s