Motility 1 Flashcards
What is chemotaxis?
Moving towards or away from chemicals
What do bacteria have that lets them do chemotaxis?
Methyl accepting chemotaxis proteins (MCPs)
Where are Methyl accepting chemotaxis proteins found?
Spanning the membrane, often at one pole of the cell
What are MCPs
Homodimeric signalling molecules that can detect different chemicals
Why are MCPs often at the pole of a cell?
SO their signals can be integrated with the motility system of the cell
What are the two types of motility that are flagella dependent?
Swarming and swimming
Difference between swarming ans swimming?
Swarming is a group of bacteria, swimming is one bacterium
Swimming is done in less viscous things
What is twitching?
Pulling them along th esurface
WHat does twitching require?
The extension and retraction of a pilus
What is gliding?
Uses diff adhesive proteins
Where are polar flagella?
One or both ends of the bacteria
Where are lophotrichous flagella?
Multiple flagella at the poles of the cells (one or both)
Where are medial flagella?
One flagella in the middle of the cell
Where are peritrichous flagella?
Many in the middle of the cell
What does movement with flagella require?
Proton motive force
How do bacteria with flagella change ow fast/slow they are moving?
They increase/decrease the rotational speed
How do bacteria go through chemotaxis?
Run and tumble
What do bacteria do when they detect something that they want to move towards?
They are running
What do bacteria do in the tumbling phase?
Working out which direction the chemo attractant is most concentrated in
What do bacteria do if there is nothing around that they want to move towards?
Random walk
Order of flagella component synthesis?
Ring proteins are synthesised first, followed by the early hook, cap and then the filament
What are the early genes involved in flagella synthesis?
Regulatory genes that control the expression of the regulation
What are the middle genes involved in flagella synthesis?
control the expression of the structural components–>HBB complex, T3SS, regulatory genes for late gene expression (P ring and L ring)
What are the late genes involved in flagella synthesis?
filament, motor force generators, and chemosensory machinery
