How is the membrane surface area increased within cells and organelles?
1. Invagination. The membranes may fold inwards so that more surface area is present without changing the volume. 2i. Cells need to get essential nutrients from outside and expel waste and they do this by transporting it across the cell membrane. The smaller the membrane size, the slower this process is, so if it’s too slow, the cell might not be able to transport enough of the stuff it needs in order to survive and function as intended. 2ii. Some things are not able to pass through the cell membrane (it’s interior is hydrophobic, so ions and large polar molecules have a tough time getting through). Still, cells need to transport ions and large polar molecules, so to accomplish this, channel proteins are used. Also, molecules tend to diffuse down their concentration gradient (i.e. they spread out), but cells need to set up concentration gradients for a number of processes (ATP generation, for example), so there are some protein channels that are able to move molecules from a low concen
