ch.5 the structure of membranes

Question 1

the membranes that encase all living cells are 2 phospholipid sheets that are only

Answer 1

5 to 10 nm thick

Question 2

the lipid layer that forms the foundation of a cell’s membranes is a bilayer formed of

Answer 2

phospholipids

Question 3

fluid mosaic model

Answer 3

a mosaic of proteins floats in or on the fluid lipid bilayer (like boats on a pond)

Question 4

cell membranes are assembled from four components

Answer 4

1. phospholipid bilayer (every cell membrane is composed of phospholipids in a bilayer).
2. transmembrane proteins (a collection of proteins that float in the lipid bilayer and function as transport and communication across he membrane).
3. interior protein network (membranes are structurally supported by intracellular proteins that reinforce the membrane’s shape).
4. cell-surface markers (membrane sections assemble in the endoplasmic reticulm (ER), transfer to Golgi apparatus, and then are transported to the plasma membrane. The ER adds chains of sugar molecules to membrane proteins and lipids, converting them into glycoproteins and glycolipids.

Question 5

two types of electron microscopes

Answer 5

-transmission electron microscope (TEM) and the scanning electron microscope (SEM).