Lipids in a bilayer can diffuse laterally at a relatively fast rate, but \"flip-flop\" from one leaflet to the other very slowly without catalysis. three protein families –flippases (or flipases), floppases, and scramblases – catalyze the movement of lipids across the bilayer. sort each of the phrases as describing flippases, floppases, or scramblases. choose the best, most-specific enzyme name. a. not atp-dependentb. activation may result in increased membrane lipid symmetryc. abc transporterd. translocate lipids from outer (extracellular) leaflet to inner (cytosolic) leaflete. translocate phosphatidylserine, preventing apoptosis and engulfment by macrophagesf. move phospolipids from inner (cytoplasmic) leaflet to outer (extracellular) leafletg. move phospohlipids across the lipid bilayer down the concentration gradient

1) Flippases  

d. Translocate lipids from outer (extracellular) leaflet to inner (cytosolic) leaflet

They are ATP dependent enzymes and they translocate phospholipids against a concentration gradient.  

2) Floppases

f. Move phospolipids from inner (cytoplasmic) leaflet to outer (extracellular) leaflet

c. ABC transporter

They move substrates such as phosphatidylcholine and cholesterol against their concentration gradient.

3) Scramblases

a. Not ATP-dependent

b. Activation may result in increased membrane lipid symmetry

e. Translocate phosphatidylserine, preventing apoptosis and engulfment by macrophages

g. Move phospohlipids across the lipid bilayer down the concentration gradient

Their enzymatic activity is bidirectional and depends on the calcium concentration.

they absorb it i think

not sure

you

not sure if this what   you'r looking for would be percent composition