membrane lipids

How can you study lipids later diffusion?

Through FRAP fluorescence recovery after photobleaching

MEMBRANE FLUIDITY.

Is the membrane fluid with hot or cold temperature?

Shorter FA interaction or longer?

Saturated hydrocarbons or insaturated

To have fluidity you need

HOT temperature

Short FA because as they are shorter they do less interactions

UNSATURATED hyrdocarbon acids beacuse as they have double bonds they form knits and so they are LESS thightly packed

Why do hot temperature increases fluidity?

Fa saturated or unsaturated increase fluidity why?

UNsaturated because by having double bonds they form kinks and have less posisbility to have dense package

How is cholesterol a fluidity buffer?

Beacuse it resists the changes in fluidity and so it stabilizes the membrane

In the colesterol which regions are rigid and which is the region that can be more fluid?

The polar head (oh)and the steroid ring are rigid

The NON polar HYDROCARBON region is MORE FLUID ( la parte lunga ch3ch2ecc)

As it acts as a buffer you need colesterol to be stable

Is colesterole fluidity with the same rules as the membrane fluidty?

NO its the opposite

High temperature increases the membrane fluidity and decreases acyl chians fluidity

Low temperature incteases acyl chain ( c=o)fluidity and constricts the membrane

THE ASSYMETRY OF THE MEMBRAIN

Which are OUTSIDE AND WHICH INSIDE

Outise: glycolipid ( carbo solo fuori!!!!) sphingomyelin and phophatylcholine and colesterol

( che sfiga che ho la colica)

Inside: phophatydilSRINE senno te va in apoptosis

PhophatylLINOSOL con cui è fatta la gpi anchor ( ma è una glico lipid la gpi anchor per quello poi va fuori) and phophatyletanolamine

What is inside in the lipid bylaer

IN: ph.serine, ph,etanolamine, ph,linositol!

Out: glycolipid, colesterol, sphigomyelin, phophtylcoline

Where can i find phophatyl coline

Che sfiga aver la colica

OUTE

Can i find disfulfde bonds in the cytosol

NO, cyto is a reducing enviroment

Disfulfide bonds can only be in the LUMEN and ( topologically eqivalent) in the extracellular space

Can gluycolipids as also ganglioside in the nervosu system be inside

NO gycolipids out

What is the glycocalix made of?

Is a coat of carbohydrate in the external part

It is made by glycolipids and glycoprotiens

Protects from mech. Stress and also a barrier against microorganism

Recptor as for diseases as colera or the recognition of the antigen and ABO groups depends on which part of the memebrnae

On the carbohydrates of the glycolipids and glycoproteins of the surface

What has been changed regarding the fluid mosaic model