2-7: Bacterial Cell Inclusions and Endospores Flashcards
What is an inclusion
Body or aggregate within cell, often related to storage
What is a microcompartment
Protein shells that encase specific enzymes/metabolites, cofactors
What is the carbon storage polymer
Carbon stored as lipids (polymer) which is formed when there is an excess of carbon/energy
Broken down when C needed
The name of the lipids in carbon storage is
poly-B-hydroxyalkanoates
Where is inorganic phosphate stored
Polyphosphate granules; broken down to produce nucleic acids, phospholipids
Where is excess sulfur stored
Sulfur storage granules
What are gas vesicles. eg?
Protein structures that keep water/solutes out, let gas in = floatation/buoyancy
Can bring microbe to favourable environment
e.g. cyanobacteria at surface of water = sunlight
What are carboxysomes
They concentrate enzymes involved in carbon fixation. Leads to increased efficiency, reduces side reactions
What is an endospore
Dormant cell that survives starvation, harsh evironment
What phylum produces endospores
Firmicutes (g+)
Are endospores the only kind of spore?
NO, diff bacteria create diff spore structures
What are endospores resistant to
Heat, radiation, drying, nutrient depletion, chemicals, etc
What is a vegetative cell
A metabolically active, growing/diving cell that become endospores upon nutrient deprivation
Can be reactivated/germinate when environment becomes favourable
How do endospores create a stable/resistant core
1) Dehydration of the core.
2) Dipicolinic acid
3) Small acid soluble proteins
What is dehydration of the core
Water from 80% to <25%. Increases resistance, inactivates enzymes
How do dipicolinic acids help endospores
Important in dehydration process, binds/stabilizes DNA
How do small acid soluble proteins help endospores
only made during sporulation
Bind DNA - make it compact, protect it from damage (UV, denaturation). Act as carbon/energy source during germination
What are the structures of the endospore
Core = house DNA/ribosome, becomes vegetative cell
Cortex = peptidoglycan layer
Two membranes = “outer membrane” not like g-; no LPS
Coat = protective protein layer`
Endospore formation picture on last slide
OK
Inclusion that allows for buoyancy?
Gas vesicles
What concentrates enzymes involved in carbon fixation
Carboxysomes
