The four main groups of organic compounds found in living things are carbohydrates, lipids, proteins, and nucleic acids. Here’s a brief overview of the basic structure of each group along with an example of a compound for each:
1. Carbohydrates
Structure: Carbohydrates are generally composed of carbon (C), hydrogen (H), and oxygen (O), typically in a ratio of 1:2:1. They can be classified into three main categories: monosaccharides (simple sugars), disaccharides (two monosaccharides), and polysaccharides (long chains of monosaccharides).
Example: Glucose (C₆H₁₂O₆) is a common monosaccharide and an important source of energy for cells.
2. Lipids
Structure: Lipids are a diverse group of hydrophobic molecules primarily composed of carbon and hydrogen, with a lower proportion of oxygen than carbohydrates. They can include fatty acids, triglycerides (glycerol plus three fatty acids), phospholipids (glycerol plus two fatty acids and a phosphate group), and steroids.
Example: Triglycerides, such as olive oil, consist of glycerol bonded to three fatty acids and are a major form of stored energy.
3. Proteins
Structure: Proteins are composed of amino acids, which are organic molecules containing a carboxyl group (–COOH), an amino group (–NH₂), a hydrogen atom, and a variable side chain (R group). They are formed by peptide bonds between amino acids, resulting in polypeptide chains that fold into specific three-dimensional structures.
Example: Hemoglobin is a protein in red blood cells responsible for transporting oxygen. It is made up of four polypeptide chains.
4. Nucleic Acids
Structure: Nucleic acids, including DNA and RNA, are polymers made up of nucleotide monomers. Each nucleotide consists of a phosphate group, a five-carbon sugar (ribose in RNA and deoxyribose in DNA), and a nitrogenous base (adenine, thymine, cytosine, or guanine in DNA; uracil replaces thymine in RNA).
Example: DNA (deoxyribonucleic acid) is a nucleic acid that carries the genetic instructions used in the growth, development, and reproduction of living organisms.
These four groups of organic compounds play crucial roles in biological processes and the overall functioning of living organisms.