Final answer:
Chemolithotrophic bacteria generate ATP by oxidizing inorganic substances through chemosynthesis, which takes place using the mechanism similar to chemiosmosis. They produce cell materials by using the energy and reducing power from this process to synthesize organic compounds necessary for cellular function.
Step-by-step explanation:
Lithotrophic bacteria, like chemolithotrophs, can make ATP by oxidizing inorganic substances, such as hydrogen gas, sulfur, or ferrous ions, instead of organic compounds. This process is known as chemosynthesis, particularly performed by bacteria that inhabit environments where sunlight is not available, such as deep sea vents.
These bacteria generate ATP through a process similar to chemiosmosis, where the flow of electrons generates a proton gradient across a membrane, which in turn drives the synthesis of ATP by ATP synthase. The energy acquired from the oxidation of inorganic compounds is thus harnessed to convert ADP to ATP, supplying the cell with the energy required for growth, maintenance, and reproduction.
The necessary cell materials are produced through assimilatory processes using the ATP and reducing power generated from chemosynthesis. Essential building blocks like amino acids, nucleotides, and lipids are synthesized from simpler molecules, incorporating elements such as carbon, nitrogen, and sulfur into organic compounds. It's important to note that chemolithotrophic bacteria are distinct from photoautotrophs, which use sunlight for energy, or chemoorganotrophs, which oxidize organic molecules.