WEEK 2 (part I): BACTERIAL CELL STRUCTURE, CLASSIFICATION, AND MORPHOLOGY

Question 1

▪ Unicellular organisms
▪ Lack a nuclear membrane and nucleus
▪ Classified as prokaryotes

Answer 1

Bacteria

Question 2

▪ Eukaryotic
▪ Exist as unicellular or multicellular
▪ Categorized by their locomotive structures

Answer 2

Parasites

Question 3

▪ Eukaryotic
▪ Exist as unicellular (yeast) or multicellular (mycelial forms)

Answer 3

Fungi

Question 4

▪ DNA or RNA core surrounded by a protein coat
▪ Acellular
▪ Obligate intracellular parasites

Answer 4

Viruses

Question 5

Is the academic discipline of defining groups of organisms on the basis of shared common characteristics and giving names to those groups.

Answer 5

Taxonomy

Question 6

three interrelated categories of Taxonomy

Answer 6

Classification, Nomenclature and Identification

Question 7

Method to categorize organisms into groups such as genus or specie.

Answer 7

Classification

Question 8

➢ Genetic makeup of the organism
➢ E.g. base sequencing of DNA or RNA

Answer 8

Genotype

Question 9

➢ Readily observable physical and functional
features expressed by the organisms genotype
➢ E.g. Macroscopic and microscopic characteristics

Answer 9

Phenotype

Question 10

Binomial system. Every organism is assigned a genus and a species name.

Answer 10

Nomenclature

Question 11

It is always written with the capital
letter while species designation is never
capitalized. Both are printed in italics or
underlined when written in script.

Answer 11

Genus

Question 12

Neisseria gonorrhoea

Answer 12

Gonococcus

Question 13

Streptococcus pneumoniae

Answer 13

Pneumococcus

Question 14

Mycobacterium tuberculosis

Answer 14

Tubercle bacilli

Question 15

Salmonella typhosa

Answer 15

Typhoid bacilli

Question 16

Klebsiella pneumoniae

Answer 16

Friedlander’s bacillus

Question 17

▪ The process by which the microorganisms key features are delineated so that it can be assigned a genus and a species name.

➢ Genotyping
➢ Phenotyping

Answer 17

Identification

Question 18

nucleus: membrane bound
chromosomal DNA: in the nucleus
organelles: present
cell wall: polysaccharides
pili and fimbriae: absent

Answer 18

Eukaryote

Question 19

nucleus: no nuclear membrane
chromosomal DNA: in the nucleoid
organelles: absent
cell wall: peptidoglycan
pili and fimbriae: present

Answer 19

Prokaryote

Question 20

single circular chromosome attached to a
mesosome

Answer 20

nuclear Area (nucleoid)

Question 21

➢ small circular, dsDNA molecule
➢ antibiotic resistance

Answer 21

plasmid

Question 22

➢ site of protein synthesis
➢ consists of RNA and protein

Answer 22

ribosomes

Question 23

represents reserves of polyphosphates used in the
synthesis of ATP.

Answer 23

metachromatic granules

Question 24

consist of glycogen and starch granules

Answer 24

polysaccharide granules

Question 25

highly refractile resting cells that are highly durable and dehydrated with thick walls

Answer 25

Spores/Endospores

Question 26

A phospholipid bilayer with embedded proteins that envelop the cytoplasm

Answer 26

Plasma Membrane (Cell membrane)

Question 27

➢ Maintains the shape of the cell and protects cell from osmotic pressure ➢ Repeating disaccharide attached by polypeptides.

Answer 27

Cell Wall (Peptidoglycan or murein layer)

Question 28

➢ Between cell membrane and cell wall. ➢ Consist of gel like matrix containing nutrient binding nutrients ➢ Contains enzymes for degrading and detoxifying macromolecules

Answer 28

Periplasm Space

Question 29

➢ Cells initial barrier (certain antibiotics and evasion of phagocytes) ➢ Composed of Lipopolysaccharides (LPS), lipoproteins and phospholipids. ➢ Contains Porins

Answer 29

Outer Membrane

Question 30

Water-filled structures that control the passage of nutrients and solutes

Answer 30

Porins

Question 31

I. Lipid A (endotoxin) II. Core polysaccharide III. O-specific polysaccharide

Answer 31

components of LPS (Lipopolysaccharides)

Question 32

gram (+) contain waxy layer of glycolipids and fatty acids (mycolic acid). e.g. Mycobacterium and Nocardia

Answer 32

Acid-Fast Cell Wall

Question 33

peptidoglycan layer: thick (multilayered) teichoic acids: present in many periplasmic space: absent outer membrane: absent LPS content: lipid and lipoprotein: virtually none lipid & lipoprotein: low

Answer 33

gram positive

Question 34

peptidoglycan layer: thin (single layered) teichoic acids: absent periplasmic space: present outer membrane: present LPS content: lipid and lipoprotein: high lipid & lipoprotein: high (due to outer membrane)

Answer 34

gram negative

Question 35

➢ Prevents phagocytosis ➢ Attachment to various surfaces in its natural environment ➢ B. anthracis ➢ S. pneumoniae ➢ K. pneumoniae ➢ General substances that surround cells ➢ Gelatinous polymer of polysaccharide, polypeptide, or both.

Answer 35

Glycocalyx (Slime Layer and Capsule)

Question 36

substance is organized and firmly attached to cell wall.

Answer 36

Capsule

Question 37

unorganized and loosely attached to the cell wall.

Answer 37

Slime Layer

Question 38

➢ Exterior protein filaments that rotate and cause bacteria to be motile

Answer 38

Flagella

Question 39

without flagella

Answer 39

Athrichous

Question 40

a single polar flagellum

Answer 40

Monotrichous

Question 41

two or more flagella at one pole of the cell.

Answer 41

Lophotrichous

Question 42

single/tuft of flagella at each end of the cell.

Answer 42

Amphitrichous

Question 43

flagella distributed over the entire cell.

Answer 43

Peritrichous

Question 44

Hairlike appendages that are shorter, straighter and thinner than flagella

Answer 44

Fimbriae and Pili

Question 45

also called common pili, can occur at the poles or can be evenly distributed from few to several hundred.

Answer 45

Fimbriae (sing. fimbria)

Question 46

FUNCTION: for adherence of cells to one another and to environmental surfaces

Answer 46

Fimbriae

Question 47

also called sex (conjugation) pili, are hollow protein tubes , longer than fimbria and number is 1 or 2 per cell.

Answer 47

Pili (pilus)

Question 48

FUNCTION: join bacterial cell in preparation of DNA transfer from one cell to another.

Answer 48

Pili (pilus)

Question 49

➢ Bundles of fibrils anchored at one end of spirochete and spiral around the cell. ➢ The rotation of filaments propels the spirochete in a spiral motion.

Answer 49

Axial Filaments (endoflagella)

Question 50

occurs in pairs - Cocci (Spherical or Ellipsoidal)

Answer 50

Diplococci

Question 51

cells arranged on chains - Cocci (Spherical or Ellipsoidal)

Answer 51

Streptococci

Question 52

irregular clusters “bunch of grapes” - Cocci (Spherical or Ellipsoidal)

Answer 52

Staphylococci

Question 53

four cells arranged in same plane - Cocci (Spherical or Ellipsoidal)

Answer 53

Tetrads

Question 54

cuboidal arrangement of 8 or more cells - Cocci (Spherical or Ellipsoidal)

Answer 54

Sarcinae

Question 55

occurs in pairs - Bacilli (Cylindrical or Rod Shape)

Answer 55

Diplobacilli

Question 56

occurs in chains - Bacilli (Cylindrical or Rod Shape)

Answer 56

Streptobacilli

Question 57

tendency to group side by side - Bacilli (Cylindrical or Rod Shape)

Answer 57

Palisade

Question 58

slightly longer than they are wide. - Bacilli (Cylindrical or Rod Shape)

Answer 58

Coccobacilli

Question 59

Cylindrical or Rod shape

Answer 59

Bacilli

Question 60

Spherical or Ellipsoidal

Answer 60

Cocci

Question 61

Spiral Shaped

Answer 61

Spirochetes

Question 62

comma shaped

Answer 62

Vibrio

Question 63

Loosely coiled

Answer 63

Spirillum

Question 64

Tightly coiled

Answer 64

Treponema

Question 65

Stain bacteria that have high lipid and wax content in their cell walls

Answer 65

Acid-Fast Stains

Question 66

Binds to the nucleic acid of the cell and fluorescence as a bright orange under UV light

Answer 66

Acridine Orange

Question 67

For observation of metachromatic granules of C. diphtheriae.

Answer 67

Methylene Blue