Phospholipids have 2 faces or poles: one hydrophobic (the tails which "run away" from water) and one hydrophilic (the heads which "like" water).
This means that when in a double layer in a aqueous environment, the heads will face the water and the tails will face each other.
The answer should be genes.
The material or substance on which an enzyme acts upon is known as the substrate, they are nothing but reacting molecules and or substances that are able to ultimately be converted to product substances. By the aid of biological enzymes, that lower the energy of activation needed for a chemical reaction to proceed.
<span>increasing the amount of algae grown at one time</span>