Bacteria Lab Flashcards
What are 3 safety procedures for this lab
1) disinfect the bench before and after the lab
2) be sure to wash your hands before and after the lab AND if you leave the lab for any reason
3) all open cuts or wounds must be covered
What is a gram positive bacteria
They have 3 layers, high peptidoglycan, negative strand test, and turn purple in a strand test
What is gran negative bacteria
Low peptidoglycan, 2 layers, positive strand test, turn pink during a strand test
Scientific name for blue green algae
Cyanobacteria
Why do blue green algae vary in colour
They have accessory pigments, certain concentrations determines the overall colour
What is nitrogen fixation and what 2 organisms can carry it out
Nitrogen fixation- changes atmospheric nitrogen into ammonia
2 organisms that do this are
- gleotrichia
- Nostoc
Describe the structure of oscillatoria
A long finger like structure that has line through it, these are separation disks
Why is Nostoc different from other blue green algae
They are able to large spherical shapes with thousands of colonies in a gelatinous matrix
What is the purpose of akinetes in gleotrichia
Protect, as they can survive harsh conditions and be inactive spores for 70-80 years
Are Cyanobacteria the same as plant cells
No cyanobacteria are prokaryotes, they do not have organelles like plants, they photosynthesize by unique fold in their membrane
What are heterocysts
Heterocsyts preform nitrogen fixation
Is gram negative or gram positive more resistant to bacteria
Gram negative are more resistant
How does a strand test work?
KOH breaks down the walls allowing the bacteria to come out
