Answer:
Surfactant is a liquid produced by the alveoli in the lungs to keep the lungs from collapsing.
Explanation:
Surfactant is a fluid composed of lipids and proteins produced in the lungs that keeps the airways open and prevent the lung from collapsing. It is secreted by the alveolar epithelial type-II (AT-II) cells of the tiny air sacs found in the lungs called alveoli. It prevents the collapse of alveoli under the surface tension by reducing the surface tension at the interface between air and the aqueous fluid lining the alveolar surfaces. If enough surfactant is not present, the surface tension causes the tissue surrounding the alveoli to stick together after each exhalation and results in the collapse of alveoli.
Usually, in unborn babies, the production of surfactant starts at about 6 months of pregnancy and the surfactant helps the babies to breathe in the air immediately after delivery. But a premature baby can not produce enough surfactant and it results in the collapse of alveoli with each breath. The damaged alveolar cells collected in the airways affect breathing and the baby takes in less oxygen. This disorder is known as respiratory distress syndrome (RDS).
The level of carbon dioxide in the blood increases and results in acidosis which affects other organs in the body. Since the premature babies having RDS need extra oxygen and help with breathing, the treatment methods include providing extra oxygen through CPAP, placing a breathing tube into your baby's trachea, providing artificial surfactant and ventilator support.
Answer:
natural selection
Explanation:
The idea of natural selection is that traits that can be passed down allow organisms to adapt to the environment better than other organisms of the same species. This enables better survival and reproduction compared with other members of the species, leading to evolution.
Acids and bases determine pH. Acids have pH 0 -7 while bases have pH 7 -14. Enzymes function within a very narrow optimum range of pH.
Different enzymes have different optimum pH values. This is the pH value at which the bonds within them are influenced by H+ and OH- ions in such a way that the shape of their active site is most complementary to the shape of their substrate.
Extreme changes in pH above or below the optimum as caused by strong bases and acids can cause the weak linkages e.g. hydrogen bonds in the enzyme's protein molecules to break permanently resulting in denaturation of the protein and impairing its functions because the enzyme can no longer conform its active site to complement that of its substrate and therefore no reaction can take place.