In an Ionic bond, a metal donates an electron and a non-metal recieves an electron. In a covalent bond, electrons are shared between two non-metals
Answer:
Hydrophilic heads facing exterior
Hydrophobic tails facing interior
Explanation:
In 1972, the fluid mosaic model was proposed to describe the structure of the plasma membrane. This model describes the plasma membrane to possess components including phospholipids, cholesterol and proteins. The phospholipid component is composed of glycerol, two fatty acids and a phosphate-containing head, which are arranged in two adjacent layers forming the phospholipid bilayer in the membrane of biological organisms.
Phospholipids have both the hydrophilic and hydrophobic region. Hence they are said to be AMPHIPATHIC.
The head of the phospholipid is negatively charged due to its phosphate content, making it polar and hydrophilic i.e. water-loving. This hydrophilic head faces the exterior of the cell in order to interact with fluids.
The tails of the phospholipid are long fatty acids that keep away from water i.e. hydrophobic. Due to their water-fearing nature, they avoid water and face the interior of the cell, where each tail face each other.
For example, when an oxygen atom binds to one of hemoglobin's four binding sites, the affinity to oxygen of the three remaining available binding sites increases; i.e. oxygen is more likely to bind to a hemoglobin bound to one oxygen than to an unbound hemoglobin.
Well, the <span>cryosphere contains 79% of Earth's frozen freshwater. Like glaciers, iceburgs, so that would be solid water. However the hydrosphere contains 100% of the water on Earth, salt and fresh.</span>
