Final answer:
Lipids are primarily composed of carbon and hydrogen. They function in energy storage, cell membrane structure, and signaling, and exist in forms such as triglycerides, phospholipids, and steroids. These compounds are hydrophobic and insoluble in water.
Step-by-step explanation:
Lipids are molecules that are primarily composed of carbon and hydrogen elements. These organic compounds include various forms like fats, oils, and cholesterol. They serve several critical functions in organisms, such as energy storage, cell membrane construction, and signaling. Lipids consist of repeating units known as fatty acids, which can be either saturated or unsaturated. The saturated fatty acids contain only single bonds between carbon atoms, while the unsaturated fatty acids include one or more double bonds, affecting the molecule's flexibility and state at room temperature.
The most common form of lipids in the human body are triglycerides, which are constructed from a glycerol backbone linked to three fatty acid chains. There are also phospholipids that are essential for cell membrane structure, providing both polar and nonpolar regions due to their unique makeup. In addition to these, steroids like cholesterol are crucial for hormone production and cell signaling. All these compounds are hydrophobic, making them insoluble in water.