Membrane proteins are among the most important proteins biologically because they allow cells to communicate with their environments. in humans, they determine whether the immune system recognizes the cell as foreign or not and they are the targets of most a) drugs b) gases c) sugars d) water

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.