The cell membrane is an extremely pliable structure composed primarily of back-to-back phospholipids (a “bilayer”). Cholesterol is also present, which contributes to the fluidity of the membrane, and there are various proteins embedded within the membrane that have a variety of functions.
A single phospholipid molecule has a phosphate group on one end, called the “head,” and two side-by-side chains of fatty acids that make up the lipid tails (Figure 1). The phosphate group is negatively charged, making the head polar and hydrophilic—or “water loving.” A hydrophilicmolecule (or region of a molecule) is one that is attracted to water. The phosphate heads are thus attracted to the water molecules of both the extracellular and intracellular environments. The lipid tails, on the other hand, are uncharged, or nonpolar, and are hydrophobic—or “water fearing.” A hydrophobic molecule (or region of a molecule) repels and is repelled by water. Some lipid tails consist of saturated fatty acids and some contain unsaturated fatty acids. This combination adds to the fluidity of the tails that are constantly in motion. Phospholipids are thus amphipathic molecules. An amphipathic molecule is one that contains both a hydrophilic and a hydrophobic region. In fact, soap works to remove oil and grease stains because it has amphipathic properties. The hydrophilic portion can dissolve in water while the hydrophobic portion can trap grease in micelles that then can be washed away.
Answer:
increase
Explanation:
The predator population will increase if the prey population increase because the predators will have more food. Hope I helped! Have a great day! ;)
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(D) Nonpoint source pollution is difficult to regulate, because its source is difficult to track.
"0.01 percent solute concentration" is the solution among the choices given in the question that <span>would cause it to swell.</span>
D. The mitochondria of the eukaryotic cells are the sites of cellular respiration and where most of the steps take place. Cellular respiration allows for the release of energy stored in chemical bonds of glucose (obtained from food) to form adenosine triphosphate, which is the energy currency of the cell.
