Introduction

Question 1

Features of prokaryotes

Answer 1

-size (smaller than eukaryotes, bigger than viruses)
-single cell
-cell wall
-asexual reproduction (binary fission)
-lateral transfer of genetic material
-short generation time
-circular chromosome
-lack of nucleus or other membrane bound organelles
-unique metabolic abilities

Question 2

Classification of bacterial species

Answer 2

1. Gram stain characteristics- based on structure of cell wall
   2.cell morphology
   3.atmospheric requirements
2. biochemical/metabolic characteristics

Question 3

Gram positive bacteria

Answer 3

-Very thick layered peptidoglycan cell wall, only an inner plasma membrane, no/very small periplasmic space, less porins present

Results in the crystal violet/iodine crystal complexes getting stuck in thick gram-positive peptidoglycan

Question 4

Gram negative bacteria

Answer 4

-Thin peptidoglycan cell wall AND has both an inner and outer cell membrane which prevents staining. Large periplasmic space present. More porins present

-decoloured!

Question 5

4 step process for staining bacteria

Answer 5

1.Crystal violet
2. Gram’s iodine
3. Acetone (decolourer)
4. Carbol Fuchsin or Safronin (counter stain)

Question 6

Cell morphology

Answer 6

spherical= cocci
rods= bacillus
spiral= spirillum

Question 7

Types of hemolysis

Answer 7

alpha-hemolysis= partial hemolysis

beta-hemolysis= complete hemolysis

gamma-hemolysis= no hemolysis

Question 8

Ways to molecularly describe species

Answer 8

-PCR and sequencing amplicons
-whole genome sequencing

Question 9

Prokaryote vs eukaryote

Answer 9

Prokaryote: uniellular microbes lacking nucleus and membrane bound organelles. (bacteria and archaea)

Eukaryote: unicellular or multicellular organisms containing nuclei and membrane bound organelles