Questions

The amount of water vapor ranges from a trace amount up to 4% of the mass of air. Water vapor exists as an invisible gas in the air.

The amount of water vapor in the air is called absolute humidity. The amount of water vapor in the air as compared with the amount of water that the air could hold is called relative humidity.

The maximum amount of water vapor that can be in the air depends on the air temperature.

Nucleic acids are polymers of individual nucleotide monomers.

Each nucleotide is composed of three parts:

a 5-carbon sugar,

a phosphate group, and

a nitrogenous base.

Many carbohydrates contain one or more modified monosaccharide units that have had one or more groups replaced or removed.

Chitin is one of many naturally occurring polymers. It is one of the most abundant natural materials in the world. Over time it is bio-degradable in the natural environment. Its breakdown may be catalyzed by enzymes called chitinases, secreted by microorganisms such as bacteria and fungi, and produced by some plants.

Chitin is composed of repeating units of N-acetylglucosamine, a nitrogen-containing form of glucose.

The protein synthesis take place in a cell outside the nucleus in the structures called ribosomes. Ribosomes link amino acids together in the order specified by messenger RNA molecules.