Biomolecules include large macromolecules (or polyanions) such as proteins, carbohydrates, lipids, and nucleic acids, as well as small molecules such as primary metabolites, secondary metabolites, and natural products.
- 14.1: Enzymes
- Most chemical reactions within organisms would be impossible under the conditions in cells. e.g., the body temperature of most organisms is too low for reactions to occur quickly enough to carry out life processes. Reactants may also be present in such low concentrations that it is unlikely they will meet and collide. Therefore, the rate of most biochemical reactions must be increased by a catalyst, which speeds up chemical reactions. In organisms, catalysts are called enzymes.
- 14.2: Lipids and Triglycerides
- A lipid is an organic compound such as fat or oil. Organisms use lipids to store energy, but lipids have other important roles as well. Lipids consist of repeating units called fatty acids. There are two types: saturated fatty acids and unsaturated fatty acids. Lipids may consist of fatty acids alone, or they may contain other molecules as well. Some lipids contain alcohol or phosphate groups. Examples include triglycerides, phospholipids, and steroids.
- 14.3: Phospholipids in Cell Membranes
- A phospholipid is a lipid that contains a phosphate group and is a major component of cell membranes. A phospholipid consists of a hydrophilic (water-loving) head and hydrophobic (water-fearing) tail (see figure below). The phospholipid is essentially a triglyceride in which a fatty acid has been replaced by a phosphate group of some sort.
- 14.4: Biological Molecules (Exercises)
- These are homework exercises to accompany Chapter 14 of the University of Kentucky's LibreText for CHE 103 - Chemistry for Allied Health.