You Have Prepared Actin Filament Seeds in a Microfluidic Chamber

question 45

Multiple Choice

You have prepared actin filament seeds in a microfluidic chamber through which you then pass either unlabeled or fluorescently labeled actin subunits in alternation several times, keeping the total monomer concentration constant. You then observe the resulting filaments under a fluorescence microscope. If the filaments appear as drawn schematically in the example below (in which fluorescence is indicated by black color) , which end do you think is the plus end-(a) or (b) ? Was the concentration of free actin subunits below or above the critical concentration (Cc) for polymerization at the barbed end?

• A) (a); below
• B) (b); below
• C) (a); above
• D) (b); above

---

Definitions:

Carrying Value

Carrying Value, also known as book value, is the value of an asset as it appears on a balance sheet, calculated by netting the asset against its accumulated depreciation.

Nonvoting Preferred Stock

A type of preferred stock that does not grant the holder voting rights in the company's shareholder meetings, typically in exchange for certain financial preferences.

Outstanding Shares

The total number of shares of stock that are currently owned by shareholders, including shares held by institutional investors and restricted shares held by insiders and company officers.

Balance Sheet

An accounting statement that captures the financial standing of a corporation by itemizing assets, obligations, and shareholders' capital at a certain time.