Break down to release of energy
Answer:
if a molecule is too large it cannot pass. also it depends on the concentration of a specific substance inside the cell. similarly, if a molecule is polar it cannot penetrate the phospholipid bilayer.
there are proteins that work as channels and pumps that allow these molecules to pass
Explanation:
Ocean currents are caused by many things. One of the main cause is the wind direction. Another cause would be density differences that is made of the temperature and the salinity of water and also currents can also be caused by events like earthquakes causing tsunamis.
Iron is a key component of hemoglobin. Hemoglobin the the protein responsible for transporting oxygen uses iron to bond oxygen. Additionally Hemoglobin is a key component of RBC (erythrocytes)... If iron is deficit the body is not able to produce red blood cells and it can result in iron deficient anemia.