Lipids and cell membranes

Question 1

What fatty acids can be absorbed into the bloodstream

Answer 1

Short and medium but not long chain. Long chains are synthesised

Question 2

What are sterols

Answer 2

They are bile acids, steroid hormones, vitamins and cell membranes

Question 3

What core do glycolipids have

Answer 3

Sphingosine core

Question 4

How is asymmetry generated

Answer 4

• New phospholipid is synthesised by enzymes at the ER facing the cytosol
• They use fatty acids available in the cytosol
• They release new phospholipid into the outer leaflet of the ER bilayer
• Lipids are then transferred to other side by flippases
• Some flippases are selective for particular phospholipids so different types may be concentrated in each monolayer