structure and function of the cell membrane

Question 1

what does the fluid mosaic model mean?

Answer 1

membrane is said to be fluid bc of the molecules of which it is made are constantly changing position, and it is said to be mosaic as its composed of many different kinds of molecules

Question 2

main structure of cell membrane

Answer 2

composed of phospholipid molecules: lipid molecules containing a phosphate group
- arranged into 2 layers (bilayer) - each phospholipid molecule has a hydrophilic head and hydrophobic tail
- arrange with head outside and tail inside, they drift form place to place with their heads and tails moving, keeping membrane fluid.

Question 3

what is inside the cell membrane

Answer 3

• cholesterol: wedged between phospholipids and importantly for function, integrity and stability of the membrane
• proteins: receptor proteins, channel proteins, carrier proteins and cell identity markers

Question 4

functions of the cell membrane

Answer 4

• to act as a psychical barrier: isolation of the cytoplasm and surrounding fluid is important because their composition is v very different
• regulates passage of materials: controls movements - entry of ions and nutrients, removal of wasts and release of secretions
• sensitive to changes: first part affected by any changes - has receptors that detect any changes
• helps support the cell: internal part of CM is attached top mcirofilaments of the cells cytoskeleton , thus giving support to the whole cell