What does it mean to be alive?
Scientifically, there is an actual definition of living. Living organisms must have certain characteristics. If they do not have these characteristics, are they living? This butterfly, like all other insects, animals, plants, and every other living organism, shares common characteristics with all life. What exactly does it mean to be alive? This chapter will answer this question. These concepts will serve as an introduction to life science, discussing the basics of studying the life sciences and addressing the question, "What is a living organism?"
Biology is the study of life, so the Life Sciences are essentially, the study of biology. The scientific method is the process by which biological information, like that of all other sciences, has been identified. This has resulted in a number of important biological scientific theories, including the cell theory and the theory of evolution. All life is built around the element carbon, and four categories of organic compounds: carbohydrates, lipids, proteins, and nucleic acids. One particular type of protein, enzymes, are biological catalysts, allowing biochemical reactions to proceed at the rate necessary to maintain life. All life can be classified into three domains. All members of these domains share characteristics in common. Viruses do not share all of the characteristics of life, and so many scientists do not consider viruses to be living.