How would a small, uncharged lipid move across the cell membrane? o through simple diffusion, down the concentration gradient
O through simple diffusion, against the concentration gradient
o through facilitated diffusion, down the concentration gradient
O through facilitated diffusion, against the concentration gradient

Through simple diffusion, down the concentration gradient.

Explanation:

The phospholipids of the membrane are amphipathic with hydrophillic heads and hydrophobic tails. Other polar molecules cannot go through this hydrophobic interior. Since small uncharged lipids are non polar and hydrohobic, they are able to go through the membrane without the help of transport proteins. Therefore, the last two options can be ruled out because facilitated diffusion includes the use of a protein. Diffusion involves molecules moving down the concentration gradient so the second option can be ruled out.

1. loamy sand is about 80% sand with 10% clay and defined mostly by sand particles with some clay to provide structure and fertility. the sand particles are easily visible and the soil holds structure but breaks apart easily.

2. scott sand can improve his soil quality by incorporating more silt and organic matter into the soil. peat moss and organic matter can also be incorporated.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.