Why is the proportion of actin within filaments in cells smaller than would be predicted by in vitro experiments?

What is the rate-limiting step in the formation of an actin filament?     Addition of actin monomers to an existing filament     None of the above     Initiation, or nucleation     Cross-linking

There are 4 types of movement based on microtubules and microfilaments. List them, as well as two consequences if each of these movement systems failed. Which of these would you say would do the least damage, and why?

Are there any diseases linked to actin filaments? Are any mutations that could halt the growth of actin filaments? I've learned about different drugs that affect filaments like Phalloidin, Cytochalasin, and Latrunculin. But other than drugs, what external environmental factors could halt the process of actin filaments from growing, and is there any diseases or illness that are associated with abnormal actin filament activity? Thank you.

If GTP hydrolysis occurs on a tubulin molecule at the plus end of a microtubule filament before another tubulin molecule is added, what typically happens to the microtubule? answer and explain

There are at least 20 different types of myosin. What properties do all types share, and what makes them different?

This graph shows the electrical charges of the cytosol at one spot along an axon or muscle cell. a) Even though the charges are the same at steps 3 and 6, explain the situation with the ions on either side of the membrane. I am not looking for a vocabulary term here, just a simple explanation in normal words. b) At step 6, this spot in the cell is not ready to conduct another action potential/impulse. What has to happen to get it ready again- and how is this done?

Which of the following regions of a sarcomere at rest is characterized by the presence of myosin only? a) A band b) H zone c) I band d) Z line

If a cell increases the activity of its actin severing proteins, will it lead in the short term to MORE or LESS actin polymer mass? Chose the most accurate answer. Increased severing activity will result in LESS polymer under any conditions. Increased severing activity will result in NO CHANGE in the total amount of polymer under any conditions. It simply results in a larger number of smaller filaments. Increased severing activity will result in MORE polymer under any conditions. If the concentration of free actin monomers is below the Cc for both the plus and minus ends, then MORE polymer will result. If the concentration of free actin monomers is above the Cc for both the plus and minus ends, then LESS polymer will result. If the concentration of free actin monomers is above the Cc for both the plus and minus ends, then MORE polymer will result. If the concentration of free actin monomers is below the Cc for both the plus and minus ends, then LESS polymer will result.

Would you expect to find motor proteins that move along intermediate filaments? Explain why or why not.