Module 3 Flashcards
What two molecular motors are found on microtubules?
Kinesin and Dynein
What are three ways to enable movement by the cytoskeleton
- Cytoskeleton “roadway” and motor protein carriers
- Reorganization of cytoskeletal network
- Motor proteins pull on the cytoskeletal “rope”
What structure organizes microtubules?
Microtubule organization center (-)
In which direction does dyenine walk? Kinesin?
Negative, positive
At which end does the microtubule grow faster?
The + end
Define dynamic instability
Balance between growth and shrinkage
Define Microtubule Associated Proteins
Proteins that contribute to the dynamic instability and organization of microtubules
Which microtubule associated motor protein is faster at walking?
Dyenin is 5x faster than kinesin
What are microfilaments composed of?
Actin
What are the two sources of movement for microfilaments?
- Actin polymerization
2. Sliding filament model
Actin comes in two different forms. What form is associated with a polymer, and what form is associated with filaments?
G-actin, F-actin
What end of a microfilament grows faster?
The + end (6-10x faster)
Define capping proteins in the context of microfilaments
Capping proteins
What is the motor protein used for microfilaments?
Actin
What are the three parts of myosin
Head, neck, tail
In the sliding filament model, the analogy of a rope and arm is used. For actin and myosin, which is each?
Actin -> the rope
Myosin -> your arm
Define the cross-bridge cycle
formation of attachment, power stroke, and release
Define unitary displacement
Distance myosin steps during each cross-bridge cycle
What two factors impact unitary displacement?
- Myosin neck length
2. Myosin placement
Define duty cycle
cross bridge cycle time
