The microbial challenge chapter 2: the microbial world. Spontaneous generation: a false but once popular theory that nonliving structures could give rise to living organisms. The cell theory does not apply to viruses and prions: that are described as acellular, subcellular and or as biological agents. A major property of life is the ability to satisfy the requirement for energy. Organic compounds: chemical compound that contains carbon: proteins, fats and carbohydrates. Organic compounds are metabolized and released into stored energy into atp. Heterotrophs: require organic compounds as an energy source: humans. Autotrophs: do not require organic compounds but do require energy: photosynthetic autotrophs: direct sunlight as energy, chemosynthetic autotrophs: energy from inorganic compounds. Heterotrophs are dependent on autotrophs for energy. Facultative anaerobes: can grow in the absence and presence of o2. Genes: are segments of the dna molecule. Dna is transferred by a variety of reproductive strategies.