In order to cross the hydrophobic interior of the bilayer, water-soluble molecules (those that are either charged or have polar groups) and large molecules require the action of membrane transport proteins. These integral membrane proteins provide a continuous protein-lined pathway through the bilayer.
Directory. A directory is a location for storing files on your computer. Directories are found in a hierarchical file system, such as DOS, OS/2, Unix, etc. When referring to a directory, a user commonly indicates the name of the directory.owever, a directory and folder are synonymous. Below is an example of what a directory path would look like in MS-DOS. In the above example, C: is the drive letter and the current directory is System32, which is a subdirectory of the Windows directory.
In the Windows , Macintosh , and some other operating system s, a folder is a named collection of related file s that can be retrieved, moved, and otherwise manipulated as one entity. The folder and file terms were chosen to be consistent with the metaphor that the user interface is a desktop . In some other operating systems, such as DOS , z/OS and most UNIX -based operating systems, the term directory is used rather than folder. This was last updated in September 2005.