The main component of the cell membrane is a phospholipid bi-layer or sandwich. The heads (the phospho part) are polar while the tails (the lipid part) are non-polar.
Low concentration to high concentration and requires energy
This disease is more common in African Americans and
females. Contractures of the fingers are classic for systemic lupus
erythematosus. The butterfly rash on the face is common, occurring in up to 40%
of affected individuals. Joint involvement is common. Pain is generally more
profound in the morning.
gas exchange is a primary example of simple diffusion,the exchange of *oxygen* and *carbon dioxide* fuels the cellular processes such as photosynthesis and cellular respiration