AP BIOLOGY

Detailed explanation-1: -Proteins, carbohydrates, nucleic acids, and lipids are the four major classes of biological macromolecules-large molecules necessary for life that are built from smaller organic molecules.

Detailed explanation-2: -11.1 Introduction: The Four Major Macromolecules Within all lifeforms on Earth, from the tiniest bacterium to the giant sperm whale, there are four major classes of organic macromolecules that are always found and are essential to life. These are the carbohydrates, lipids (or fats), proteins, and nucleic acids.

Detailed explanation-3: -There are four classes of macromolecules (polysaccharides or carbohydrates, triglycerides or lipids, polypeptides or proteins, and nucleic acids such as DNA & RNA). Carbohydrates and lipids are made of only carbon, hydrogen, and oxygen (CHO). Proteins are made of carbon, hydrogen, oxygen, and nitrogen (CHON).

Detailed explanation-4: -The four main classes of organic compounds (carbohydrates, lipids, proteins, and nucleic acids) that are essential to the proper functioning of all living things are known as polymers or macromolecules. All of these compounds are built primarily of carbon, hydrogen, and oxygen but in different ratios.

Detailed explanation-5: -This video excerpt from NOVA explains what astrobiologists consider to be the three basic ingredients of life-water, organic compounds, and energy.