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.
One of these is the root directory, which is the top level directory on a system. That is, it is the directory in which all other directories, including their subdirectories, and files reside. The root directory is designated by a forward slash (/).