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.
Our skin has receptors and muscles also have receptors which tells brain about how much tension is being exerted on it etc.
Carbon dioxide, or CO2.
Plants produce oxygen for us to breathe, and in exchange they take the gas we breathe out: carbon dioxide.
Answer: 5… I think
Explanation: sorry if I’m wrong.
The Scientific method can help resolve problems logically.
<u>Explanation:</u>
A logical and systematic approach that is used for the discovery of working of things in the world is known as Science. The scientific methods are used by the scientists for the purpose of evidences that can be measured and associated with the assumed hypothesis. The result of this method will be either supporting or contradicting to the theory.
The term "science" refers to the knowledge whose base is from some reproducible data. The result is obtained through the process of analysis and testing. It aims in finding solutions to any problem through logic and research.
