Lecture 3: Microbial Cell Structure/Function Part 2 Flashcards
What are pili?
Thin protein appendages on the outside of the cell that help with attachment and can facilitate horizontal gene transfer
- What genus is this?
- What life domain does it belong to?
- What type of environement does it live in?
- Haloquadratum
- Archaea
- High salt environement
What type of bacteria is this and why (2 reasons)?
Gran negative bacteria because there is an outer membrane and a THIN layer of peptidioglycan
What kind of genetic material do archaea have?
Have circular, double stranded DNA chromosomes as well as plasmids
What is methanogenesis?
What doman of life is it unique to?***
Biological production of methane gas (very potent greenhouse gas)
Unique to archaea
What happens to the motion of a cell as the concentration of attractant increases?
What is this flagellation pattern?
Polar (1 end of the cell) monotrichous
- What organism is this?
- What life domain is it from?
- It is a source of _____ for ______
-
Pyrociccus furiosus aka “rushing fireball”
- one of Dr. Mohr’s favorite organisms
- Hyperthermophile (85-113 degrees)
- Can live in extremem environement due to the archaea membrane
- Has more than 50 flagella
- Archaea
- Source of Pfu polymerase for PCR
Do Archaea have plasma membranes?
****
Yes, archaea have plasma membranes, aka lipid bilayer, cytoplasmic membrane
What type of motion do repellents cause?
What’s that motion called?
Cause clockwise motion
Called tumble
The flagella fly apart, cells then tumble and change their direction
What flagellation pattern is this?
Peritrichous—-flagella spread out all over the entire surface
What is the collective pattern of runs + tumbles called?
Random walk
What flagellation pattern is this?
Lophotrichous: cluster of flagella at one or both ends
This is specifically polar lophotrichous because flagella only at one end of the cell
What temperature range do hyperthermophiles live in?
85-113+ degrees C
How does the size of most archaea compare to bacteria?
Similar sized to bacteria, in the um (micrometer) range
What are Type IV Pili?
Dynamic (can move) that can extend and retract, which is called
“twitching motility”
Where do archaea live?
Live in terrestrial and aquatic environements
What are the areas labelled called?
- Filament
- Made up from flagellen protein
- Hook
- Connects basal body to the filament
- Basal body
- Series of rods and circular rings/discs that make up the motor
- H+ protons moving into the cell to provide energy for the basal body (proton gradient)
What are functions of external structures on microbes?
- Attachment
- Horizontal gene transfer (via sex pili)
- Movement (flagella)
What kind of motion do attractants cause? (CW or CCW?)
What direction is that motion in?
What is it called?
Cause counterclockwise motion.
Flagella bundle together
Cells “run” forward
How do archaea reproduce?
Asexually
What are the proteins in the cell membrane?
What do they do/perform?
Chemoreceptors
They detect componds in the external environment and aid in chemotaxis (sensory system that enables microbes to move towards or away from specific chemicals)
What temperature range do thermophiles live in?
Live in 45-85 degree C temperatures
Do archaea have cell walls?
****
Some archaea have cells walls, but DO NOT HAVE petidoglycan (NAG-NAM).
Other archaea don’t have cell walls but have a protein based S-layer
