Lab #1: Prokaryotes

Question 1

Prokaryotic Organisms

Answer 1

• structurally simple
• do not have membrane-bound organelles
• divided into 2 subgroups: Domain Bacteria, and Domain Archaea

Question 2

Domain: Bacteria

Answer 2

• cell walls contain peptidoglycan

- bacteria are divided into 2 groups depending on the structure of the cell wall.

Question 3

Gram Staining

Answer 3

• Gram Positive Bacteria: stain purple, have a thick layer of peptidoglycan in their cell walls.
• Gram Negative Bacteria: stain pink, have a think layer of peptidoglycan in cell walls. Are often pathogenic.

Question 4

Phylum: Actinobacteria

Answer 4

• gram positive
• phylum is well known for its ability to produce compounds that have antibiotic or antifungal properties

ex: Bifidobacterium lactis

Question 5

R.O. - Bifidobacterium lactis

Answer 5

Domain: Bacteria, Kingdom: Bacteria, Phylum: Actinobacteria, Genus: Bifidobacterium

• added to yogurt, lives in human digestive tract
• unicellular organism, grows in aggregates called colonies
• gram positive, non-motile
• saphotrophic (heterotrophic, uses extracellular digestion)
• probiotic bacteria (improves human digestion)

Question 6

Phylum: Cyanobacteria (Blue-Green Algae)

Answer 6

• autotrophic
• uses photosynthesis
• aquatic organism
• produces oxygen

ex: Anabena

Question 7

R.O. - Anabena

Answer 7

Domain: Bacteria, Kingdom: Bacteria, Phylum: Cyanobacteria, Genus: Anabena

• grows multicellular filaments, surrounded by a gelatinous sheath
• reproduces asexually by fragmentation
• cells contain large numbers of interfolded membranes called thylakoids
• heterocyst: slightly larger, thick-walled cell that fixes nitrogen

Question 8

Domain: Archaea

Answer 8

• can survive extreme temperatures (hot and cold)

ex: Halobacterium

Question 9

R.O. - Halobacterium

Answer 9

Domain: Archaea, Kingdom: Eukarya, Phylum: Euryarchaeota, Genus: Halobacterium

• lives in saline water
• prevents dehydration via halorhodopsin (light-driven chloride pump that maintains high salt levels in organism)
• photoheterotroph (red protein called bacteriorhodopsin)
• produces gas vesicles that allow it to float on the surface
• can use flagellum to swim