Cell Membrane October 9 Flashcards
What are the three main functions of a cell membrane?
- Like a plastic bag, it gives structure to the cell
- Like a brick, it gives it stability and protection
- Like a sieve, it filters and lets certain things in or out
What factors influence its functioning?
Temperature, pH and viruses
What are its 7 components? (GGCCCPP)
Glycoproteins, glycolipids, cholesterol, carrier proteins, channel proteins, phospholipid bilayer, peripheral protein
Describe glycoproteins
They’re receptor molecules. They bind with hormones, stabilize the membrane and help it with its recognition
Describe glycolipids
They stabilize, help in reception and communication. Their main difference is being used as an anchor for proteins.
Describe cholesterol
It increases the fluidity of the membrane, making it survive temperatures
Describe carrier proteins
They change their shape to selectively allow certain molecules to pass by DIFFUSION or ACTIVE TRANSPORT
Describe channel proteins
They make hydrophilic tunnels across the membrane, giving a better environment for certain molecules by DIFFUSION
Describe the phospholipid bilayer
It acts as a barrier to the passage of IONS and molecules going in or out of the cell, SELECTIVELY
Describe the peripheral proteins
They support the cell membrane’s attachments and communication.
What are the three levels of tonicity?
Hypotonic, isotonic and hypertonic
What is a hypotonic solution?
When there’s a lower concentration of solutes, so water moves INTO the cell
What is an isotonic solution?
When they both have the same concentration of solutes, so nothing happens
What is a hypertonic solution?
When there’s a higher concentration of solutes, so water moves OUT of the cell
Explain the relationship between solvents, solutes and solutions
A solvent is a substance that dissolves another substance, called the solute, to form a solution. Water, Salt, saltwater
