Plasma Membrane

Question 1

What is the role of the plasma membrane?

Answer 1

• Provides protection and a fixed environment for the cell
• Transports nutrients into the cell and bacteria out of the cell

Question 2

What are phospholipids

Answer 2

the main component of the plasma membrane which form the phospholipid bilayer.

Question 3

What are the two parts of a phospholipid?

Answer 3

• The phosphate head which is negatively charged polar and hydrophilic meaning that it loves water. Made of phosphates and glycerol. the heads are orientated towards the water and the aqueous intra and extracellular environments.
• The lipid tail which are long tails made of carbon and hydrogen. They are uncharged, nonpolar and hydrophobic meaning they repel against water. The tails are orientated away from the water and make up the middle of the bilayer.

Question 4

What is amphipathic?

Answer 4

A molecule with both hydrophobic and hydrophilic components.
Eg. Phospholipid.

Question 5

What is amphipathic?

Answer 5

A molecule with both hydrophobic and hydrophilic components.
Eg. Phospholipid, this makes the plasma membrane stable.

Question 6

Elements of the plasma membrane?

Answer 6

∆ Cholesterol - Regulates fluidity in plasma membrane , while also helping the phospholipids stay in the right direction and bond with each other. Attached to lipid and proteins.
∆ Phospholipids - the main component of the plasma membrane which form the phospholipid bilayer.
∆ Glycoproteins - Antenna used to pick up bacteria to repel or release, if something is needed in the cell then glycoprotein will pick up and pull into the cell.
∆ Peripheral proteins - Communication – receive signals or recognise cells and molecules. Often attached to the cytoskeleton to transmit signals into the cell
∆ Channel protein - pore in the membrane that lets water molecules or small ions through quickly
∆Carrier protein - bind specific solutes and transfer them across the lipid bilayer by undergoing conformational changes.

Question 7

What is bulk transport?

Answer 7

With the use of vesicles large molecules of large groups of molecules can move through the plasma membrane

Question 8

Difference between endocytosis and exocytosis

Answer 8

endocytosis is into the cell
exocytosis is out of the cell