W04_01 Microbial classification

Question 1

what are the 4 major classes of microorganisms?

Answer 1

bacteria, viruses, fungi, parasites

Question 2

how big are bacteria?

Answer 2

0.1-10 um

Question 3

how big are viruses?

Answer 3

0.03-0.3 um

Question 4

name the steps of the gram stain

Answer 4

fixation onto glass slide by heat or methanol; crystal violet (1 minute); iodine (1 minute); decolorize with alcohol (seconds); safranin stain (30-60 seconds)

Question 5

what keeps the crystal violet in the gram-positive cells?

Answer 5

very thick peptidoglycan layer in the cell-wall. essentially gram-positive = thick, and gram-negative = thin

Question 6

how can we further classify the cocci?

Answer 6

pairs; diplococci; chains; clusters

Question 7

what 4 kinds of aerobes are there?

Answer 7

strict aerobes; facultative aerobes; microaerophilic; aerotolerant

Question 8

name the gram-positive cocci

Answer 8

staphylococcus spp

streptococcus spp

enterococcus spp

Question 9

name the gram-positive bacilli

Answer 9

corynebacterium spp

bacillus

clostridium spp (anaerobe)

Question 10

name the gram-negative cocci

Answer 10

neisseria spp

haemophillus spp (coccobacilli)

Question 11

name the gram-negative bacilli

Answer 11

e.coli

haemophilus spp (coccobacilli)

bacteroides spp (anaerobe)

Question 12

name 2 important DNA viruses

Answer 12

hepatitis B

herpesviruses

Question 13

name 5 important RNA viruses

Answer 13

hepatitis A, C, E

influenza A, B

HIV

Rotavirus

Norovirus

Question 14

what are the two big fungi classification groups?

Answer 14

yeast (recall these “bud” to reproduce)

filamentous fungi (moulds)

Question 15

what’s a mycelium?

Answer 15

a collection of hyphae

Question 16

what’s the most important yeast genus for us to know?

Answer 16

candida spp.

Question 17

what are the two big parasite classifiers?

Answer 17

protozoa

helminths (worms)