2.7 Bacterial Cells Flashcards
What are inclusions and what types of cells have them?
- Prokaryotic cell has them
-inclusions aggregate in cells and are often related to the storage of a substance.
What are microcompartments and who has them?
-bacterial cells
- protein shells that encase specific enzymes, metabolites, and cofactors, that carry out specific metabolism.
What are the three things Carbon inclusions allow for?
- Carbon storage (PHB)
- P, S, Carbonate storage (carbonate permits biomineralization)
- Gas Vesicle
what is carbon storage (PHB)?
- basically when bacteria stores carbon when times are good, to be accessed during periods of starvation.
- prokaryotes store carbon as lipids called poly-beta-hydrooxyalkanoates (PHA), the most common is poly-beta hydroxybutyric acid (PHB)
- the PHB polymer is produced when there is an excess of carbon, it aggregates and forms large vacuoles.
- theses polymers are then broken down for carbon and energy when needed.
What is polyphosphate and sulfur carbonate storage?
- inorganic phosphate is stored in polyphosphate granules (excess phosphate). This then is broken down to produce nucleic acids and phospholipids.
- sulphur storage granules produced by bacteria (and archaea) that oxidize reduced sulphur compounds for energy.
a. used energy to fuel metabolism
what is gas vesicles?
- in gas vesicles bacteria and archaea can float since they produce gas vesicles.
- these are basically structures that keep water and solutes out but allow only gas in
- This keeps them a property of buoyancy, which brings these microbes to a favourable environment. (ex. water wings)
-ex. cyanobacteria blooms at the surface of the water which allows for more sunlight, and efficient photosynthesis.
What are micro-compartments?
- they are polyhedral protein shells that encase specific enzymes, metabolites and cofactors.
- it is used to protect against toxic intermediates, reactive intermediates and byproducts.
what are carboxysomes?
- they are concentrate enzymes involved in carbon fixation.
- they help in crease the efficiency and reduce unwanted side reactions.
- oxygen will compete with co2
Modification of Endoscopes
- highly retractile and thick-walled structures formed inside the bacterial cells
- they are highly differentiated, are sleeping cells that can survive starvation and very harsh environmental conditions.
a. can have a microbial cell change to a different lifestyle. - they are only produced by Firmicutes (gram positive) –> much more resistant than others.
what are endospores resistant to?
- they are resistant to extreme heat, radiation, drying, nutrition depletion, and chemicals.
- they can long years –> germinate –> grow again.
What is an analogy of Endospores?
- it is basically like freezing your self and preserving your self without any technology.
what are endospores? what kind of cells are they?
- They are vegetative cells that differentiate into endospores upon nutrition deprivation (starvation)
a. they are metabolically active, growing and dividing cells. - they are usually activated when the environment becomes favourable, the spore can be activated, germinate and return to a vegetative state.
what are the two features of endospores?
- They need to shut off metabolism, cell activities
- Provide resistance and stability.
i) has a program that protects you
form UV light for example.
What is the key for creating a stable and resistant core?
- Dehydration of the core is KEY.
a. the water goes from greater than 80% of water (vegetative cell) to less than 25% of water (dehydrated cell) - Dehydration helps increase the resistance to the removal of moisture, heat, and chemicals. it inactive cells enzymes via denaturation.
What is Dipicolinic Acid (DPA)?
- unique characteristics of a spore.
- it is complex with ca2+
- important for dehydration processes. and binds/stabilizes DNA.
a. if you loose DNA –> game over = important to stabilize DNA
