Structure of Cell Membranes Flashcards
What is the Plasma membrane?
Membranes consisting of a phospholipid bilayer found around and within all cells
What is Partially membrane?
A membrane that allows water and other small molecules to pass through, but not larger or polar molecules
What do Plasma membranes do?
They keep the components of the cell isolated from the external environment and compartmentalise cellular functions by separating the inside of organelles from the cytoplasm
What is the Fluid Mosaic model?
Fluid- the phospholipids move laterally
Mosaic- Proteins are scattered in different patterns
What is the function of Phospholipid bilayer?
Forms a barrier to dissolved substances. The centre of the bilayer is hydrophobic so doesn’t allow water soluble substances through but does allow small, non-polar molecules like CO2 to diffuse through
What are Intrinsic proteins?
Channel proteins and carrier proteins allow large molecules, polar molecules and ions to pass through the molecules: Facilitated diffusion
What are the function of Peripheral proteins?
Can act as receptors and allow the cell to detect chemicals released from other cells so that they can respond
What is a Glycoprotein?
A protein with carbohydrate attached
What is a Glycolipid?
A lipid with carbohydrate attached
What is the function of Glycoproteins and Glycolipids?
Act as antigens to facilitate cellular recognition. Play an important role is cell signalling and communication. Also help with cell adhesion, making connections that allow cells to connect to one another to form tissues
What is the function of Cholesterol?
Restricts movement of other molecules in the membrane and gives it stability by binding to the tails of phospholipids and causing them to pack together more closely. Reduces their movement and makes the membrane less rigid. Has hydrophobic region so acts as a barrier to polar substances moving through the membrane
