Читать книгу Introduction to the Human Cell - Danton PhD O'Day - Страница 17

The “fluid mosaic model” emphasizes the cell membrane is fluid. This “fluidity” wasn't always appreciated by earlier scientists since early models of the cell membrane were very rigid. It took a diversity of early experimentation and observation over many decades to clarify that the cell membrane was indeed fluid. After all, in hind sight, we know that cell division would not be possible with a solid, inflexible membrane. Similarly, skeletal muscle forms by the fusion of cells called myoblasts as covered later in this volume. The sperm and egg must fuse to form a zygote. But fundamental work was required to provide experimental evidence for membrane fluidity. This is summarized in Figure 2.12.

Figure 2.12. Early experiments revealing the fluid nature of the cell membrane.

This collection of diverse experiments thus showed:

•If you cut Amoeba proteus in half with glass needle, both halves survive and crawl away

•If you stick a glass needle into a frog’s egg, it seals up and the egg remains normal

•If you treat cells with certain viruses or electricity, cells that don't normally fuse will fuse together