Q1 . The fundamental requirement for a living cell to sustain itself are a carbon source, an energy source, an electron donor, an electron acceptor and elemental nutrients(N,P, S, Mg,) etc. Explain how each of these fundamental requirements are needed by the living cell to function. Explain how the cell can maintain its own internal biological processes without being in equilibrium with the external environment.
The living cells can function within a constricted range of such conditions such as nutrient availability, pH, ion, temperature, etc. The cell must coordinate different chemical reactions and consolidate many different molecules into definite structures, and these reactions are known as metabolism. All cells need carbon to assimilate organic compounds to create new cell material. In addition to C, O, and H, many other elements such as elemental nutrients – N, P and S are needed in smaller amounts. Phosphorus is the main element in nucleic acids and phospholipids. Sulfur is found in several vitamins and amino acids. Potassium is needed for the activity of several enzymes while the role of magnesium is to stabilize membranes, ribosomes, and nucleic acids. The oxidation–reduction reactions in cells release energy that is stored in energy-rich compounds, such as ATP. Oxidation involved the removal of an electron and reduction is the gain of an electron to a substance.
The cell can regulate its internal conditions and can stabilize its functioning within its internal environment regardless of the outside changing conditions. This is also stated as homeostasis. Cells have certain structures that carry out specific jobs. These organelles are responsible for the energy capture, transport of materials, waste disposal, protein building and storage within a single cell.
Q 2. The basic chemical building block for a living cell are carbohydrates, fatty acids, nucleic acids and amino acids with water as the water as the solvent. Describe what the cellular components in bacteria are created from these building blocks. Describe the function of these cellular components. Explain how (why) water is the ideal solvent for biological systems.
A single cell is made of macromolecules—proteins, lipids, polysaccharides and nucleic acids that are made of fatty acids, nucleotides, amino acids, and sugars. Proteins are the major part of the composition of the cell. Bacteria are prokaryotes and carry membrane-bound organelles, and with chromosomes but lack a well-defined nuclei. Complex carbohydrates in bacteria form a protective covering for them. The cell walls in bacterium are made of polysaccharides that add to the strength of the wall. The cytoplasm is a gel-like matrix composed of water. Plasmids are small genetic structures in bacteria made of nucleic acids and amino acids. Cytoplasmic Membranes are made of phospholipids and proteins.
The biological molecules, their functioning, and structure is determined by the aqueous solution conditions in which they function. The solvent properties of water affects the structure of many proteins and carbohydrates. Most biological compounds being polar are soluble in water. All essential chemical reactions for life take place in the main solvent in the body that is water.
Q 3. Metabolism is the process where the compounds form the environment are broken down into simple compounds and then combined into complex cellular components. Both these process are linked to energy within the cell. A bioreactor is a design to optimize these processes however, bacterial growth is controlled. Explain why the bacteria in a closed bioreactor will grow and eventually decay into four phases. Explain what the bacteria are doing metabolically and what the environmental conditions are in each phase. If a phototroph bacteria is used to treat latex in the presence of ammonium sulfate in a bioreactor, indicate whether the carbon source, energy source and the electron acceptor is in the bioreactor.
Bioreactor ensures the right conditions for microorganisms' reproduction. The cultivation process of the bacteria starts with the preliminary preparations. The reproduction of the culture is characterized by 4 phases: Lag phase, Exponential phase, Stationary phase and Death phase. During the lag phase, the cell metabolism in bacteria is working on synthesizing enzymes, and the length of this phase can vary. The next stage is the growing phase, the exponential phase, where the bacterial cells undergo division and increase their population. The dramatic rise in the growth amount is related to the period in a certain quantity of the nutrients. The growth stops once the nutrient resources are finished, and the stationary stage sets in. The bacteria cell metabolism is still going on and is followed by the process of sorting out the secondary metabolite. If the fermentation is sustained for some period in the stationary stage, the death phase sets in.
If a phototroph bacterium are used to treat the latex in the presence of ammonium sulfate in a bioreactor, the fundamental biochemical mechanisms control carbon and electron flow to conserve energy.