Studied by 0 people
Looks like no one added any tags here yet for you.
Which two components of the cytoskeleton are involved in cell motility and which is not?
Microtubules and microfilaments are involved, intermediate filaments are not
What is the motor protein associated with F-actin?
Myosin
What are the motor proteins associated with microtubules?
Kinesin and dynein
How large is one ‘step‘ of a motor protein?
8nm
How many ‘steps’ does a motor protein take each second?
40
In what direction does kinesin travel and along what filament?
Microtubules, from - end to + end (from MTOC to cell periphery)
In what direction do dyneins travel and along what filament?
Microtubules, from + to - (from periphery to MTOC)
In what directions do most myosins travel and along what filament?
Actin, from - to +
In what directions does myosin VI travel and along what filament?
Actin, from + to -
Describe one example of one way polymerisation of actin filaments can be used in a cell to generate force
Listeria is a bacterium that gives you food poisoning. It gets taken up into the cytoplasm of the gut cell and once inside ActA, an actin nucleating protein, stimulates actin to polymerise and form comet tails of actin filaments. The actin is human actin not the bacterium’s own actin. This allows the bacteria to infect neighbouring cells.
In a sarcomere, to which disc (A-Z) are all filaments anchored?
Z disc
How many different classes of myosin are there?
At least 15
Which number myosin (1-15) is ‘conventional‘ myosin?
II
What does myosin V do?
Organelle motor actin used typically for short-range movements vs microtubule motors
What makes myosin VI unusual?
It travels in the opposite direction to most myosins
Which sensory process are myosin VI and VII involved in?
Hearing
Describe crawling cell locomotion
Polymerisation coupled with adhesion causes the cell to move forward. Actin formation creates lamellipodia, adhesion formation, actin-myosin contraction causes tail to retract.
What is a lamella
The flattened portion of the nucleus in crawling cell locomotion
How do cilia and flagella differ in size?
Flagella (60 micrometres) are about 10x bigger than flagella (6 micrometres)
What is an axoneme?
The core of a cilium or flagellum, composed of microtubules
Describe the arrangement of microtubules in an axoneme
9+2 arrangement of 9 doublet microtubules and one central pair
The action of which motor protein causes sliding action between adjacent doublets?
Dynein
How does the movement of the axoneme differ in cilia and flagella?
In cilia the axoneme creates a whipping motion, whereas in cilia the axoneme twists in an oscillating wave
What is the general name of diseases linked to cilia?
Ciliopathies
What is the longest nerve to exist?
The recurrent laryngeal nerve, which controls the larynx
Where is most myosin II found (lamellipodium, filopodium or stress fibres)?
Stress fibres
