Hopefully, now that you know what to look for, these 20 amino acids are not too complicated molecularly. In fact, the only thing that is different in these 20 amino acids is the group of atoms attached to the central carbon at this central carbon's fourth covalent bond (by convention, shown above the central carbon). For example, the simpliest amino acid only has a single hydrogen atom attached as this side group.
Water vapor and particles of dust can also be found in the earth's air. Clouds float only in the troposphere, or the lowest part of the atmosphere. It is also here that all of the earth's wind, storms and other features of weather take place. The troposphere extends upward to a height of about 10 miles. Air gets thinner the farther it gets from earth. The stratosphere extends from the troposphere to about 30 miles above the earth. It is in this air that many jet airplanes fly.
The height of the troposphere varies from the equator to the poles. At the equator it is around 11-12 miles (18-20 km) high, at 50Â°N and 50Â°S, 5Â½ miles and at the poles just under four miles high. As the density of the gases in this layer decrease with height, the air becomes thinner. Therefore, the temperature in the troposphere also decreases with height in response. As one climbs higher, the temperature drops from an average around 62Â°F (17Â°C) to -60Â°F (-51Â°C) at the tropopause.