Chapter 4 Bacteria + Archaea Flashcards
Packaging of DNA in Bacteria and Archea
Nuclear material that is free in cytoplasm
Bacteria + Archaea Internal Structure
have no membrane-bound organelles
Bacteria cell appendages
Flagella, Pilus, Nanowires and Fimbriae
Bacteria Cell Surface Layers
S layer and Glycocalyx
Bacterial cell boundary
Cell wall and cytoplasmic membrane
Bacterial cell internal properties
cytoplasm, ribosomes, inclusions, nucleoid/chromosome, cytoskeleton, endospore, plasmid, Microcompartments
Nanowires/nanotubes
Membrane extensions that allow bacteria to transmit electrons or nutrients to other bacteria or onto environmental surfaces
Endospore formation
-triggered by lack of nutrients
-usually Gram-positive bacteria
-enables bacteria to lie dormant for extended periods
-bacterium divides within its cell wall
Bacteria carry out all life activities which are?
-Reproduction
-Metabolism
-Nutrient processing
bacteria acting as a group
-Colonies
-Biofilm
Bacterial shapes
-Coccus (round)
-Coccobacillus (round rod)
-Bacillus (rod)
- Vibrio (Curved)
-Spirillum (spiral)
-Spirochete (tight spiral)
Pleomorphism
-Variations in size and shape among cells of a single species
Cocci Grouping
-Coccus (single sphere)
-Diplococci (pairs)
-Tetrad (groups of four)
- Staphylococci (irregular clusters)
- Streptococci (chains)
- Sarcina (cubical packet of 8, 16 or more)
Bacilli Arrangements
-Bacillus (single)
- Diplobacilli (Pairs of cells w/ ends attached)
-Streptobacilli (chains of cells)
-Palisades (side by side row of cells)
Bacterial Appendages for motility
-Flagella: rotates 360 degrees
-Axial filaments
Bacterial appendages for attachment or channel formation
PIlus/pili
Fimbria/fimbriae
nanowires
Three distinct parts of flagella
-Filament :composed of protein inserted into hook
-Hook: curved and tubular, attached to basal body
-Basal body: composed a rod and rings anchored through the cell wall to the cytoplasmic membrane and the outer membrane.
Flagellar arrangement
-Polar: Monotrichous, Lophotrichous, Amphitrichous
-Peritrichous
Monotrichous Flagella
Single flagellum
Lophotrichous flagella
Small bunches or tufts of flagella
Amphitrichous flagella
Flagella at both poles of the cell
Peritrichous flagella
Dispersed randomly over the surface of the cell
Run and Tumbles
Run: counterclockwise movement of flagellum in a straight line
Tumble: reverses direction causing cell to stop and change course
Positive Chemotaxis
Movement of a cell toward a favorable chemicle stimulus
Negative Chemotaxis
Movement of a cell away from repellent or harmful compound
Phototaxis
Movement toward light
Axial filament
-Motility appendage for spirochetes
-They are internal flagellum enclosed between the cell wall and the cytoplasmic membrane
-Twisting or flexing movement
pili/pilus
-Mostly found in Gram neg bacteria
-Used in Conjugation (partial transfer of DNA from one cell to another
-production of Pilus is controlled genetically