Ch. 4 NotesThis is a featured page

The following came from my notes that I typed up in a flashcard-format to help me study for the test. The answers came mainly from the lecture slides, and also more details from the textbook. I hope this might be beneficial to somebody, besides just me! -Amber Timothy
Ch. 4 Notes: A Survey of Prokaryotic Cells and Microorganisms
1. Prokaryotic characteristics vs. Eukaryotic characteristics
2. Three parts of prokaryotic structures
3. Three types of appendages
4. Binary fission
5. Three parts of flagella
6. Four types of flagellar arrangements
7. Three ways to detect motility of bacteria
8. Chemotaxis/phototaxis
9. Spirochetes
10. Axial filaments
11. Fimbriae
12. Biofilm
13. Chitin/chitosan
14. Pili (pilus)
15. Cell envelope
16. Glycocalyx
17. Periplasmic space
18. Capsule
19. Slime layer
20. Phagocyte
21. Gram stain
22. Differences between gram-positive and gram-negative bacteria cell walls
23. Virulence
24. Macrophage
25. Streptococcus pneumonia
26. Bacillus anthracis
27. Cell wall
28. Peptidoglycan
29. Hans Gram
30. Lipid A
31. Endotoxin
32. Differences of cell walls between gram-positive and gram-negative bacteria
33. Four groups based on cell wall composition
34. Gram-negative outer membrane
35. Acid-fast
36. Mycobacterium
37. Mycoplasma
38. Lysis
39. Cell membrane
40. Mesosome
41. Functions of the cell membrane
42. Fluid mosaic model
43. Cytoplasm
44. Chromosome
45. Nucleoid
46. Plasmids
47. Ribosomes
48. Inclusions/granules
49. Endospores
50. Sporulation
51. Germination
52. Why are endospores so resistant?
53. Pathogenic endospore formers
54. Three shapes of bacteria
55. Arrangements of bacteria
56. Sepsis
57. Protoplast and spheroplast

Answers:
1. Prokaryotes: One circular chromosome, not in a membrane; no histones; no organelles; petpidoglycan cell walls; binary fission; bacteria and archaeobacteria. Eukaryotes: Paired chromosomes, in nuclear membrane; histones, organelles; polysaccharide cell walls (or none); mitotic spindle; all other living organisms.
2. Outside cell: Appendages (include flagella/periplasmic flagella, pili, & fimbriae), and cell envelope (includes glycocalyx, cell wall and cell membrane). Inside cell: cytoplasm (includes cell pool, ribosomes, granules, and nucleoid/chromosome).
3. 1 – Flagella allows motility. 2- Fimbriae allows attachment. 3 – Pili allow “mating.”
4. A simple process of a cell splitting into two. How prokaryotic cells reproduce.
5. Flagella rotate 360 degrees. There are 1-2 or many of them distributed over entire cell. 1 – Filament – long, thin, helical structures composed of proteins. 2 – Hook – where the filament is inserted into the cell. 3 – Basal body – a stack of rings firmly anchored in the cell wall; where the hook is anchored to the cell.
6. 1 – Monotrichous – single flagellum at one end. 2 – Lophotrichous – small bunches arising form one end of the cell. 3 – Amphitrichous – Flagella at both ends of the cell; operate only one side of flagella at any time, allowing them to quickly reverse direction. 4 – Peritrious – Flagella dispersed randomly over the surface of the cell; slowest.
7. 1 – Can use electron microscope to see flagellar arrangement. 2 – Can do a “stab” into a semisolid media. Growth spreading rapidly through the entire medium is indicative of motility. 3 – Can use a hanging drop slide and watch movement. This is the quickest and easiest way.
8. Chemotaxis – flagellated bacteria can detect and move in response to chemical signals. Phototaxis – a type of movement in response to light rather than chemicals.
9. Corkscrew-shaped bacteria that flexes and twists and wiggles when it moves due to its two or more axial filaments. Treponema pallidum (the cause of syphilis) is a spirochete.
10. An “internal flagella” within the periplasmic space (the area between the cell wall and cell membrane). Also called periplasmic flagella. Found in all spirochetes. Looks like a wiggly worm when in motion.
11. Fine, hair-like bristles from the cell surface. Function in adhesion to other cells and surfaces—not locomotion.
12. Composed of millions of microorganisms that accumulate on surfaces in aqueous environments. These film-forming microbes excrete a glue-like substance that anchors them to materials.
13. The main component of crustacean shells. Biofilms can’t grow on it. Approved by FDA to staunch blood loss.
14. Rigid, tubular structure made of a special protein, pilin. Found only in gram-negative cells. Functions: joins bacterial cells for DNA transfer (conjugation), and adhesion.
15. External covering that lies outside the cytoplasm. Composed of two main layers; the cell wall and cell membrane. All cells have a cell membrane; most have a cell wall, also; many have a glycocalyx (either a slime layer or capsule).
16. Coating of molecules outside the cell wall. Made of sugars and/or proteins. Two types: capsule and slime layer. Functions: attachment, prevent phagocytosis, important in formation of biofilms.
17. The area between the cell wall and the cell membrane.
18. Highly organized repeating polysaccharide units or proteins, tightly attached to the cell and not readily removed. Encapsulated bacterial cells have greater pathogenicity because they protect against white blood cells.
19. A loosely organized and attached shield that is easily washed off. Protects cells from dehydration and loss of nutrients. 20. White blood cells that engulf and destroy foreign cells, which helps to prevent infection. Capsules protect the bacteria against phagocytes.
21. A differential stain for bacteria and taxonomy. Most useful lab technique in microbiology. Uses crystal violet for the primary dye, iodine for the mordant, an alcohol rinse for the decolorizer, and safranin for the counterstain. Bacteria stained purple = gram-positive, stained red = gram-negative.
22. Gram-positive: one major layer; chemical composition of peptiglycan, teichoic acid, lipotechoic acid, mycolic acids and polysaccharides; the peptidoglycan wall is thicker, which entraps the primary dye more; no outer membrane; narrow periplasmic space; and more penetrable to molecules.
Gram-negative: two major layers (outer membrane and a thinner shell of peptidoglycan); chemical composition of lipopolysaccharide, lipoprotein, peptidoglycan, and porin proteins; thinner than gram-positive; extensive periplasmic space; and less penetrable to molecules.
23. In infection, the relative capacity of a pathogen to invade and harm host cells.
24. A white blood cell derived from a monocyte (a type of white blood cell) that leaves the circulation and enters tissues. These cells are important in nonspecific phogocytosis and in regulating, stimulating, and cleaning up after immune responses. 25. A pathogen that causes pneumonia, otitis media, meningitis, and sinusitis. Its primary determinant of virulence is its polysaccharide capsule, which prevents ingestion by macrophages.
26. The cause of anthrax. A large, spore-forming rod, gram-positive.
27. Between cell membrane and the glycocalyx. Determines shapes of bacteria, proves structural support to prevent bursting of the cell; relatively rigid due to peptidoglycan.
28. A unique macromolecule composed of a repeating ramework of long glycan chains (called NAG-NAMS) cross-linked by short peptides. Forms the rigid part of bacterial cell walls. Provides strong, flexible support to keep bacteria from bursting or collapsing because of changes in osmotic pressure. Only found in prokaryotes.
29. He invented the Gram stain in 1884.
30. An endotoxin only found in gram-negative bacterial cells (in the cell wall).
31. A bacterial intracellular toxin that is not ordinarily released. An integral part of gram-negative bacterial cell walls. Can cause shock and fever.
32. The gram-positive cell wall is a thick layer of peptidoglycan. Also contains tightly bound acidic polysaccharides, including techoic acid and lipoteichoic acid. It retains crystal violet and stains purple. Affected by lysozyne and penicillin.
The gram-negative cell-wall is more complex because it’s composed of an outer membrane containing lipopolysaccharide, and a thinner shell of peptidoglycan. No teichoic acids. It also has a periplasmic space and an outer membrane. It loses crystal violet and stains red from the safranin counterstain. Resistant to penicillin. Contains lipid A, which is an endotoxin.
33. Gram-positive cells, gram-negative cells, bacteria without cell walls, and bacteria with chemically unique cell walls.
34. Composed of lipopolysaccharides, lipoproteins, and phospholipids. Protects from phagocytes and antibiotics. Porins (proteins) form channels through membrane.
35. Does not lose its primary stain in the presence of acid. This staining procedure is used to diagnose tuberculosis and leprosy.
36. A bacterial genus that has a waxy cell wall and retains dye even when washed with acid (i.e. acid-fast). Don’t qualify as gram-positive or gram-negative. Causes leprosy and tuberculosis.
37. A bacteria that lacks a cell wall and thus varies in size or shape. Very tiny bacteria. Most species are parasites of animals and plants.
38. The physical rupture or deterioration of a cell.
39. In-between the cell wall and the cytoplasm. A phospholipids bilayer with embedded proteins.
40. When the membrane forms inward folds into the cytoplasm. More prominent in gram-positive than gram-negative bacteria.
41. Because bacteria don’t have eukaryotic organelles, the cell membrane provides a site for energy reactions (ATP synthesis), nutrient processing and synthesis of proteins. Another major action is to regulate transport (the passage of nutrients into the cell and the discharge of wastes). Also involved in secretion (the release of a metabolic product into the extracellular environment) of enzymes and toxins.
42. A model that says membrane is slippery and viscous, proteins float around like icebergs in a sea, and phospholipids rotate and move laterally.
43. The substance inside the plasma membrane. Contains the cell pool, ribosomes, granules, and nucleoid/chromosome.
44. Single, circular, double-stranded DNA molecule that contains all the genetic information required by a cell. Bacteria only have one chromosome.
45. A central area of the cell where the DNA is aggregated, tightly coiled around a protein. The primary sites of genes.
46. Non-essential pieces of small, circular, double-stranded DNA (“extra” DNA). Can exist freely or be integrated into chromosome. Are duplicated and passed on to offspring; may encode antibiotic resistance and tolerance to toxins. Easily manipulated in the laboratory and transferred from cell to cell, so they are important in genetic engineering.
47. Site of protein synthesis in the cell (ribosomes read RNA to make proteins). Made of 60% ribosomal DNA and 40% Protein. All cells have ribosomes.
48. Intracellular storage bodies that bacterial cells use when environmental sources of nutrients are depleted.
49. A small, dormant, resistant bacterial cell that can withstand hostile conditions and facilitate survival. Produced by the bacteria Clostridium and Bacillus. Has a two-phase life cycle that shifts between a vegetative cell and an endospore. Only found in gram-positive cells.
50. The process of spore formation.
51. The return of an endospore to vegetative growth.
52. Their resistance is linked to high levels of calcium and dipicolinic acid (which makes them heat resistant). They are dehydrated and metabolically inactive (also making them less vulnerable to heat), and they have a thick coat (to protect against radiation and chemicals).
53. Bacillus anthrasis causes anthrax, Clostridium tetani causes tetanus, Clostridium perfringens causes gas gangrene, Clostridium botulinum causes botulism.
54. Coccus (spherical), bacillus (rod), and spirillum (helical, twisted rod, spirochete).
55. In singles; pairs (called diplococci or diplobacilli), in groups of four (called tetrads), in packets of 8, 16, or 32 (called sarcinae). Also in chains (called streptococci or streptobacilli) or in irregular clusters (called staphylococci or staphylobacilli). Vibri (like a comma) is another common shape, as are palisades (columns).
56. The presence of pathogenic organisms or their toxins in tissue or blood.
57. A protoplast is a gram-positive cell that loses its peptidoglycan from lysozume or penicillin and thus loses its cell wall and becomes very fragile. A spheroplast is a gram-negative cell that loses its peptidoglycan but still has its outer membrane, and thus becomes weak but not as fragile as a protoplast.


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