WEEK 5 Flashcards
What is the purpose of cellular membrane?
- Spacial definition of a cell
- Transport of specific molecules into and out of the cell
What are the three main transportation methods?
- Diffusion
- Osmosis
- Active transport
What are cellular membranes made of?
Phospholipid bilayer
What are phospholipids made of?
- Phosphate head= polar=hydrophilic
- Fatty acid tails=non-polar=hydrophobic
What is the best word to describe a phospholipid?
amphipathic+area of polar and non polar
What are the main properties of the phospholipid bilayer?
- Fluid
- Cell membranes are mosaic
What is the Membrane held together by?
vandewalls
How do saturated fatty acid tails affect the fluidity of the membrane?
Become less fluid, because the fatty acid tails can pack more tightly together.
How do unsaturated fatty acid tails affect the fluidity of the membrane?
Become more fluid. There is a double bond in the tail causing a kink therefor the fatty acids cannot pack as tightly together.
What is the purpose of cholesterol?
membrane integrity
How does cholesterol help Membrane integrity?
It is amphipathic. therefor it is able to lodge itself between the phospholipids, with the polar head associating with phosphate head and the non-polar part associates with fatty acid tails therefore provides a way of associating the lipids together
What does it mean when the membrane is described as mosaic?
It s made up of lipids and proteins
What are the two major types of proteins found in the membrane?
- Integral proteins
- Peripheral proteins
What is an integral protein?
proteins that are permanently associated with the cell membrane due to hydrophobic regions that associate with hydrophobic area of membrane
What is a peripheral protein?
Don’t permanently attach to membrane, they are wither on one side or the other and interact with something that is permanently embedded
