READING TASK 3 - MICROPHY (PAHABOL SA QUIZ) PDF

1. Microbial Nutrients and 2. Energetics, Enzymes, and Nutrient Uptake Redox Feeding the Microbe: Cell Nutrition Energy Classes of Microorganisms Microorganisms require a variety of Microorganisms can be classified ba...

1. Microbial Nutrients and 2. Energetics, Enzymes, and Nutrient Uptake Redox Feeding the Microbe: Cell Nutrition Energy Classes of Microorganisms Microorganisms require a variety of Microorganisms can be classified based on nutrients to sustain growth and metabolism. their energy sources: These nutrients are categorized into macronutrients and micronutrients. - Phototrophs: Use light as their Macronutrients include carbon, nitrogen, primary energy source. oxygen, hydrogen, phosphorus, sulfur, - Chemotrophs: Obtain energy from potassium, magnesium, and iron. chemical compounds, which can be Micronutrients include trace elements such further divided into: as manganese, zinc, cobalt, molybdenum, - Chemoorganotrophs: Use nickel, and copper, which are vital for organic compounds. enzymatic functions and other biochemical - Chemolithotrophs: Use activities. inorganic compounds. Transporting Nutrients into the Cell Principles of Bioenergetics Nutrients are transported into microbial cells Bioenergetics involves the study of energy through several mechanisms: flow through living systems. Key principles include the laws of thermodynamics, - Passive Diffusion: Movement of particularly the concept of Gibbs free energy small molecules (e.g., gasses) (ΔG), which determines the spontaneity of across the cell membrane without biochemical reactions. energy input. - Facilitated Diffusion: Involves carrier Catalysis and Enzymes proteins to move molecules down their concentration gradient. Enzymes are biological catalysts that speed - Active Transport: Uses energy up reactions by lowering activation energy. (usually from ATP) to move They are highly specific and their activity substances against their can be regulated by inhibitors (competitive, concentration gradient via specific noncompetitive) and allosteric modulators. transport proteins. - Group Translocation: A form of Electron Donors and Acceptors active transport that chemically modifies the molecule being Redox reactions are critical for energy transported into the cell, using production, involving the transfer of energy from high-energy compounds electrons from electron donors (oxidized) to like phosphoenolpyruvate. electron acceptors (reduced). These reactions are fundamental in processes such as cellular respiration and photosynthesis.  Electron Transport and the Proton Energy-Rich Compounds Motive Force Compounds such as ATP (adenosine The electron transport chain (ETC) is a triphosphate) store and transfer energy series of protein complexes that transfer within cells. ATP hydrolysis releases energy electrons through redox reactions. As that can be used for cellular work, including electrons move down the chain, protons are biosynthesis, transport, and movement. pumped across the membrane, creating a proton motive force (PMF). This gradient 3. Catabolism: Fermentation drives the synthesis of ATP via ATP synthase. and Respiration Options for Energy Conservation Glycolysis and Fermentation Microorganisms have various strategies for Glycolysis is the process of breaking down energy conservation, including glucose to pyruvate, yielding ATP and substrate-level phosphorylation during NADH. In the absence of oxygen, pyruvate glycolysis and oxidative phosphorylation via is further metabolized through fermentation the ETC. Anaerobic respiration uses to regenerate NAD+, producing end alternative electron acceptors, while products such as lactic acid or ethanol, and chemolithotrophy exploits inorganic yielding less ATP than respiration. molecules for energy. Respiration: Citric Acid and Glyoxylate Cycles 4. Biosynthesis - Citric Acid Cycle (Krebs Cycle): Sugars and Polysaccharides Pyruvate is oxidized to CO2, generating NADH and FADH2, Sugars are synthesized through pathways which donate electrons to the like gluconeogenesis, converting electron transport chain. non-carbohydrate precursors into glucose. - Glyoxylate Cycle: A variation of the Polysaccharides, such as glycogen and citric acid cycle that allows peptidoglycan, are synthesized for energy organisms to convert fatty acids into storage and structural purposes, carbohydrates. respectively. Respiration: Electron Carriers Amino Acids and Nucleotides Electron carriers such as NADH, FADH2, Amino acids are synthesized through and coenzyme Q (ubiquinone) shuttle pathways that derive intermediates from electrons to the electron transport chain, glycolysis, the citric acid cycle, and the facilitating the generation of a proton pentose phosphate pathway. Nucleotides gradient across the membrane. are synthesized from precursors such as ribose-5-phosphate (from the pentose phosphate pathway) and amino acids, forming the building blocks for DNA and RNA. Fatty Acids and Lipids Fatty acids are synthesized from acetyl-CoA through a series of condensation reactions. These fatty acids are then incorporated into complex lipids like phospholipids and triglycerides, essential for cell membrane structure and energy storage. Understanding these processes is fundamental for comprehending how microorganisms function, adapt, and interact with their environment. This knowledge is crucial in fields such as microbiology, biotechnology, and medicine, providing insights into microbial physiology, metabolic pathways, and potential applications in industry and healthcare.