Lecture 17- Synthesis Of Membrane’s Lipids

Question 1

How is the membrane synthesized

Answer 1

By inserting new lipids to the cytosolic side of the membrane then it is flipped to the opposite leaflet by flippase .

Question 2

Where are membrane lipids synthesized

Answer 2

Membrane lipids are synthesized in the integral proteins of smooth endoplasmic reticulum.

Question 3

Which Lipids are not made in SER

Answer 3

1- sphingomyelin
2- Glycolipids
3- Unique lipids of mitochondria and chloroplasts

Question 4

Describe the composition of lipids in the membrane

Answer 4

1- Composition of lipid is assymetric
2- It also varies from organelle to organelle
- variable percentages of phospholipids
- presence or absence of specialized lipids
- mitochondria and chloroplasts have very different membrane CONSTITUENTS

Question 5

How are membrane’s lipid moved?

Answer 5

1- some organelle already have enzymes embedded in their membranes
2- some phospholipid is preferentially incorporated into budding vesicles
3- cells contain phospholipid(PL) transfer proteins that move PLs from the ER to other organelles