Transport Across a Cell Membrane. The cell membrane is one of the great multi-taskers of biology. It provides structure for the cell, protects cytosolic contents from the environment, and allows cells to act as specialized units.
How to Amend the Constitution. Article V of the United States Constitution provides authority and instructions for amending the Constitution. Amendments can be proposed by Congress or by constitutional convention. Congress then decides how to ratify the amendment if approved by Congress or convention.
Article 5 of the Constitution provides for the amendment of the Constitution by various means (see The Amendments Page for details). However an amendment is proposed, it does not become part of the Constitution unless it is ratified by three-quarters of the states (either the legislatures thereof, or in amendment conventions).