Membranes and Lipids

What is delta naming of fatty acids?

#totalCarbons:#ofDBCarbonsΔ^(PositionofDB)

What are the structural lipids?

Phopholipids and Sphingolipids

What are the properties of a phospholipid?

Polar headgroup, glycerol, 2 FA tails; amphiphatic for lipid bilayer

What are the properties of sphingolipids

Amphiphatic for membrane, used in cell-signaling

What Lipid is used for long term energy storage?

Triacylglycerols

What is the effect of TAGS being neutral and hydrophobic?

Allows packing and doesn’t interupt cell processes

How are TAGS broken down?

Hydrolyzed by Lipases for energy production in Beta-Oxidation

What are the 3 signaling lipids?

Sterols, Eicosanoids, and Glycerphospholipids

What are the properties of sterols?

Long range signaling and affects membrane properties

What are the properties of eicosanoids?

Short term Signaling, not in blood

What are the properties of glycerophopholipids?

Polar headgroup and 2 FA tails; used to activate secondary messengers.

Do longer or shorter FA tails increase fluidity?

Shorter due to less VDW interactions

Do saturated or unsaturated FAs increase fluidity?

Unsaturated

How does temperature affect membrane fluidity?

Hot → Inc fluidity, Cold → Dec fluidity

How are lipids transported through blood?

Lipoproteins

Why are membranes asymmetrical?

Allows certain domains and functions on each side of the membrane

What effects does membrane assymetry allow?

Electric encironments, structure and biological regulation, prevents PS on outer leaflet (Phagocytosis)

How does flippase move lipids?

Outer leaflet to Inner leaflet

How does Floppase move lipids?

Inner leaflet to outer leaflet

How does Scramblase move lipids?

Evenly distributes lipids, disrupts assymetry; activated by Ca2+ damage marker for phagocytosis

What are the relative speeds of transverse and lateral diffusion?

Transverse is slow, lateral is fast

How do integral membrane proteins exist?

In membrane

How do peripheral membrane proteins exist?

Associate with one leaflet

How do amphitrophic membrane proteins exist

Associate reversibly

What is the difference between mono, bi, and polytopic membrane proteins?

Mono → Goes through one leaflet, Bi → goes through both leaflets, Poly → goes through both leaflets many times

What is simple diffusion?

Nonpolar compounds moving down a concentration gradient

What is facilitated diffusion?

Compounds moving down electrochemical gradient

What is primary active transport

Moves against EC gradient using ATP

What is Ionophore mediated ion transport?

Moves down EC gradient

What are ion channels?

Ions moving down EC Gradient

What is secondary active transport?

Moving against EC Gradient by ion movement