Hydrophobic head

2 FA tails

Inserted in PM

[image]

Polar head, 1 FA tail with a sphingosine backbone

[image]

sphingosine + 1 FA tail

[image]

sphingolipid

ceramide, phosphate, choline

(similar to phosphotidylcholine)

[image]

sugar, sphingomyelin, FA

NO PHOSPHATE

[image]

glycolipid: glc/gal + ceramide

found in nerve tissue and brain cell membranes

• myelin sheath (made of sphingomyelin and galactocerebroside) is destroyed by person's immune system
• decreases ability to conduct nerve signal
• affects vision, sensation, coordination, movement, bladder and bowel
• symptoms are episodic at first and worsen over time

• type A and B
  • deficiency in sphingomyelinase causes accumulation in spleen, liver, lungs, bone marrow, brain
• type C
  • buildup of cholesterol or glycolipids in liver, spleen, neural cells
• progressive neurological impairment
  • life expectancy varies with severity and age of onset

• monotopic
• single pass
• multi pass
• multisubunit
• FA anchor
• GPI anchor

• Inner leaflet only
• Growth signaling--must be connected to PM
• 3 types FA

attaches to glycine on N terminus

14 carbons

attaches to cysteine on C terminus

Farnesyl

Geranyl Geranyl

attaches to internal cysteine

16 carbons

usually involved with proteins that have been prenylated or myristolated to increase anchoring in PM

1. Lateral diffusion
2. Rotation
3. Transverse diffusion--flippase

can comprise 50% of total lipids in PM

even distribution on both faces

restricts movements of phospholipids

decrease fluidity and permeability to small molecules

[image]

• short chain FA- increase fluidity
• unsaturation-increase fluidity
• increase temp increase fluidity
• cholesterol decreases fluidity

[image]

sugars in ECM adsorb water to cushion cells and to provide chemical and mechanical support

common on RBC, epithelial cells, and platelets

important in clotting and sperm-egg interactions