Final answer:
The differences in Myosin II action, which involves walking along microfilaments and driving muscle contraction, contrast with kinesin, which walks along microtubules to transport vesicles without muscle-like contraction.
Step-by-step explanation:
Differences in Myosin II and Kinesin Motor Activities
The differences in Myosin II action and kinesin correlate with their distinct motor activities within the cell. Myosin II, a motor protein that utilizes ATPase activity to walk along microfilaments, plays a crucial role in muscle contraction and cellular movements such as cell division and cytoplasmic streaming. Actin and myosin II are abundant in these muscle cells where their interaction causes muscles to contract.
Kinesin, on the other hand, is a motor protein that 'walks' along microtubules. It is involved in the anterograde transport of cargo such as neurotransmitter vesicles from the neuron cell body to nerve endings. The ATP-dependent movement of kinesin is essential for the movement of materials throughout the cell, which is different from the contractile movement driven by Myosin II.
Visual examination using electron microscopy has revealed that myosin heads are flexible and capable of adopting multiple conformations, crucial for the micro-contraction cycle. This dynamic ability of myosin II to change conformation and interact with actin filaments contrasts with kinesin's primary role in vesicle transport, which does not involve the same level of interaction with actin filaments.