Study Guide Chapter 4 Done Flashcards
Describe the different shapes and cellular arrangements found in bacteria
- Bacillus: Rod Shaped
- Coccus: Spherical shaped
List and explain the characteristics of bacterial colony morphology
Size, shape, texture, edges (margins)
Arrangement: pairs, clusters, bunches, chains etc.
Differentiate between flagella, pili, fimbriae and their role/arrangement
- Flagella:
Filament appendages external of the cell; propels bacteria allowing them to move; made of protein flagellin; 3 Parts: 1. filament: outer most region 2. Hook: Attaches to the filament 3. Basal Bodies: Consists of rod and pair rings; anchors flagellum to cell wall and membrane - Pili: Protein called adhesions are involved in its role for attachment to surfaces
- Fimbriae: Allows for attachment to surfaces (hand/finger like)
Differentiate between Glycocalyx, cell envelope, cell wall and membrane
Glycocalyx:
- external to cell wall
- made of polysaccharides
- Functions: Environmental protection and adhesion to surfaces
- 2 types: capsule: thick layer; slime layer: thinner layer
Cell envelope: Cell membrane and wall together
Cell Wall: prevents osmotic lysis and protects the cell membrane
- Contributes to pathogenicity
- Made up of peptidoglycan
Describe the composition of peptidoglycan
Carbohydrate backbone (NAM and NAG), Held together by peptide bonds (creates the layer) and then peptide bonds hold the other layers so they can stack
Differenciate between gram +, gram - and acid fast and atypical bacteria (cell walls)
- Gram +: thick peptidoglycan layers and Teichoic Acid
- Gram -: Thin peptidoglycan layer no teichoic acid
- Acid Fast: Like gram positive walla, have a waxy lipid (mycolic acid) that is bound to the peptidogycan
- Atypical: Lack cell walls; has sterols in the plasma membrane
Describe the composition of cell walls and hpw it determines g- or g+
Gram +: Thicker so it retains the crystal violet
Gram -: Thinner to the crystal violet rinses and the safrian sticks
CV,
Describe the composition of a cell membrane
Can be damaged by soap/detergent because they disolve the bilayer
Bilayer is the phospholipid biolayer
Differentiate between nucleoid, bacterial chromosome, plasmid, genome
Nucleoid: Sub-compartments containing a single bacterial chromosome
Bacterial Chromosome: Circular thread of DNA and associated proteins
Plasmids: small, extrachromosomal genetic elements, carries 5-10 nonessential genes that provide characteristics to the cell
Differentiate b/w ribosomes, inclusion bodies, reserve granules, gas vesicles, Magnetosomes
Ribosomes: site of protein synthesis, hundreds-thousands per cell made of protein and RRNA
Inclusion Bodies and Reserve Granules:
- Metachromatic granules (volutin)-phosphate reserves
- Polysaccharide granules-energy reserves
- Lipid inclusions- energy reserves
- Sulfur granules- energy reserves
Gas Vesicles:
Protein-covered cylinders that maintain buoyancy used to float on the waters surface
Magnetosomes:
Contain crystals of magnetic iron oxide or gregigte allowing cells to respond to magnetic fields
Structure of Prok. Ribosomes
2 subunits: Large and small
Composition of Prok Cytoskeleton
o Composed of three types of proteins:
A homolog of eukaryotic tubulin that forms filaments similar to those found in microtubules
Proteins homologous to the eukaryotic actin (microfilaments) that can determine the cell shape
Crescentin, a homolog to eukaryotic intermediate filaments that also assists in cell shape
Define Pure colony is bacteria and explain the importance
Pure colony: Group of Microorganisms that grow from a same parent cell on an agar
Important because you get to know exactly what you are looking at
List the components found in bacterial cells with emphasis on location
Outer
Appendages (flagella, pili and fimbriae)
*Glycocalyx
*Envelope (cell wall and cell membrane
*Cytoplasm
*Internal structures-
Nucleoid
- Ribosomes-
Inclusion bodies-
Reserve granules
- Cytoskeleton
inside
