BIOl 151 1st Edition Lecture9Outline of Current Lecture I. Requirements for lifeII. ProkaryotesIII. Reproduction of prokaryotesIV. Biogeochemical CyclesCurrent LectureI. Requirements for lifeThere are several requirements for life by any organism on Earth; they are the ability to obtain food, the exchange of gases, the maintenance of proper water and solute balances, the removal of waste and the ability to reproduce. II. ProkaryotesThe two main domains of prokaryotes are Archaea and Bacteria; these organisms are categorized by their simple cell structures. Both Archaea and Bacteria lack a nuclear membrane,lack membrane-bound organelles, contain circular chromosomes and are extremely small in size. Bacteria also contain plasmids, or small circular DNA that may carry genes that are important for adapting to different environments. Bacteria and Archaea have structural support through a cell wall and a peptidoglycan, which act as the membrane. The small size of the prokaryotes allows them to diffuse carbon and other organic molecules faster and easier than a larger cell. Archaea and Bacteria tat live in extreme environments are known as extremophiles.III. Reproduction of ProkaryotesBacteria and Archaea reproduce asexually, through binary fission, which means that one parent cell divides in half and thus producing a daughter cell. Genetic variation is maintained through mutation and horizontal gene transfer. Mutations occur randomly and could be small point mutations or large chromosomal mutations. There are three different types of horizontal gene transfer. The first type is conjugation and occurs when a tube called a pilus forms between two cells and DNA travels through the tube from the donor cell to the receiving cell. Bacterial transformation occurs when a donor cell dies and the recipient cell consumes the leftover DNA. The last type of horizontal gene transfer is called Bacterial transduction, and is most common These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.with viruses. A virus attaches to a donor cell causes it to break open and then it infects the recipient cell.IV. Biogeochemical CyclesProkaryotes play an important role in many biogeochemical cycles that are important for thesurvival of other organisms. The simple carbon cycle is where carbon and water are used in photosynthesis and then produce sugar and oxygen to be used in respiration. The evolution of cyanobacteria allowed for the accumulation of oxygen in the atmosphere. A microbial mat was studied to understand the importance of the prokaryotes in the carbon cycle. The first layer wasfull of cyanobacteria or the oxygenic, photosynthetic bacteria. The next layer contained bacteriathat produced anoxygenic photosynthesis, where it did not produce oxygen but used the sunlight to produce ATP. The last layer contained bacteria that used anaerobic respiration, where they recycle carbon in the areas with low or no oxygen present. The different layers of bacteria produce the ATP and the carbon needed for other organisms to