Microbiology and Parasitology Quiz #1 (Midterms) PDF

microbiology and parasitology SEP 313 BSSE 3A | Shutzly Fe N. Kabingue | SEM 1 2024 Carbohydrate Catabolism- is the CH 1. MICROBIAL METABOLISM breakdown of carbohydrate...

microbiology and parasitology SEP 313 BSSE 3A | Shutzly Fe N. Kabingue | SEM 1 2024 Carbohydrate Catabolism- is the CH 1. MICROBIAL METABOLISM breakdown of carbohydrate molecules to produce energy. ex: What is metabolism? glucose -The buildup and breakdown of nutrients The most common pathway for within a cell. oxidation of glucose is glycolysis. - Provide energy and create substances Pyruvic acid is the end product. that sustain life. Glycolysis yields two ATP and two 1. Enzymes- catalyze reactions for NADH molecules are produced specific molecules called from one glucose molecule. has substrates. Substrates are three main stages; 1. preparatory transformed into new substances 2. spitting 3. energy harvest or called products. conserving 2. ATP (Adenosine Triphosphate)- To produce energy from glucose, a molecule that cells use to microorganisms use two general manage energy needs. processes: Cellular Respiration and Fermentation. Pathways can be categorized into two general types: 1. Cellular Respiration- defined as an ATP- generating process in 1. Catabolic- [exergonic] catabolic which molecules are oxidized and pathways breakdown into simple the final electron acceptor comes component parts, releasing energy from outside the cell and is an in the process. energy releasing inorganic molecule. 2. Anabolic- [endergonic] ]anabolic Types of Respiration pathways build up macromolecules Aerobic Respiration- final by combining simpler molecules, electron acceptor is O2. using energy in the process. energy using Catabolic reactions provide the energy needed for anabolic reactions. 1 microbiology and parasitology SEP 313 BSSE 3A | Shutzly Fe N. Kabingue | SEM 1 2024 subsequently utilized for various physiological functions. Proteins are too large to pass unaided through plasma membranes. Microbes produce extracellular proteases and peptidases, enzymes that break down proteins into their component amino acids Deamination - the amino group of ATP production produces 38 atps an amino acid is removed and (correction in the figure). converted to an ammonium ion (NH4+), which can be excreted Anaerobic Respiration- final from the cell. electron is an inorganic molecule Decarboxylation (the removal of other than O2 or, rarely, an organic —COOH). molecule. Desulfurization (removal of 2. Fermentation- is defined as a —SH) process that; releases energy from sugars or other organic molecules; CH 2. MICROBIAL GROWTH does not require oxygen (but can The Requirements for Growth occur in its presence); Physical Requirements does not require the use of the Temperature Krebs cycle or an electron transport chain; uses an organic molecule synthesized in the cell as the final electron acceptor. In Lactic Acid Fermentation, pyruvic acid is reduced by NADH to lactic acid. In Alcohol Fermentation, acetaldehyde is reduced by NADH to produce ethanol. Lipid Catabolism- is the metabolic process by which lipid (fats and oils) are broken down to produce energy. Fats are lipids consisting of fatty acids and glycerol. Microbes produce extracellular pH enzymes called lipases that break -most bacteria grows best at a pH value fats down into their fatty acid and between 6.5 and 7.5 glycerol components. -few bacteria grow at an acidic pH below The Krebs cycle functions in the about pH 4 oxidation of glycerol -acidophiles Protein Catabolism- is the Osmotic Pressure metabolic process by which - the net movement of water molecules proteins are broken down into their across a selectively permeable membrane constituent amino acids and 2 microbiology and parasitology SEP 313 BSSE 3A | Shutzly Fe N. Kabingue | SEM 1 2024 -the minimum pressure applied to a solution to prevent an inward flow Plasmolysis Chemical Requirements Obtaining Pure Cultures Carbon -the structural backbone of living matter Streak Plate Method -needed for all the organic compounds A visible colony theoretically arises that make up a living cell from a single spore or vegetative N, S, Phosphorus cell or from a group of the same -nitrogen makes up about 14% of the dry microorganisms attached to one weight of a bacterial cell another in clumps or chains. -sulfur and phosphorus constitute about another 4% Trace Elements -essential for the functions of certain enzymes, usually cofactors -assumed to be naturally present in tap water Oxygen 1. obligate aerobe 2. facultative anaerobe 3. anaerobes 4. aerotolerant anaerobe 5. microaerophiles Organic Growth Factors -essential organic compounds an organism is unable to synthesize -organic compounds such as amino acids, Preserving Bacterial Cultures purines, pyrimidines, and vitamins that a cell must have for growth but cannot Deep-freezing synthesize itself. Lyophilization (freeze-drying) -most vitamins function as coenzymes, the organic cofactors required by certain The Growth of Bacterial Cultures enzymes to function 1. Bacterial Division Biofilms -The normal reproductive method of a thin, slimy layer encasing bacteria is binary fission, in which a single bacteria that adheres to a surface cell divides into two identical cells. can be considered a hydrogel -a few bacterial species reproduce by most bacteria live in biofilms budding. 2. Generation Time Culture Media 3 microbiology and parasitology SEP 313 BSSE 3A | Shutzly Fe N. Kabingue | SEM 1 2024 -The time required for a cell to divide or a 1. Plate Counts population to double -a heterotrophic plate count reflects the number of viable microbes and assumes that each bacterium grows into a single colony; plate counts are reported as the number of colony forming units (CFU). -a plate count may be done by either the pour plate method or the spread plate method. 2. Filtration -in filtration, bacteria are retained on the surface of a membrane filter and then 3. Logarithmic Representation of transferred to a culture medium to grow Bacterial Population and subsequently be counted. -bacterial division occurs according to 3. The Most Probable Method logarithmic progression (MPN) -2 cells, 4 cells, 8 cells, and so on. -can be used for microbes that will grow in a liquid medium; it is a statistical Bacterial Growth Phase estimation. 4. Direct Microscopic Count -The microbes in a measured volume of a bacterial suspension are counted with the use of a specially designed slide. Estimating Bacterial Numbers by Indirect Method 1. Turbidity -A spectrometer is used to determine 1. The Lag Phase turbidity by measuring the amount of light -intense activity preparing for population that passes through a suspension of cells. growth, but no increase in population 2. Metabolic Activity -during the lag phase, there is little to no -this method assumes that the amount of change in the number of cell, but a certain metabolic product is in direct metabolic activity is high proportion to the number of bacteria 2. The Log Phase present. -logarithmic, or exponential, increase in 3. Dry Weight population -the fungus is removed from the growth -during the log phase, the bacteria multiply medium, filtered to remove extraneous at the fastest rate possible under the material, and dried in a dessica tor, then conditions provided. weighed. 3. The Stationary Phase -during this phase, there is an equilibrium CH 3. CONTROL OF GROWTH between cell division and death 4. The Death Phase HEADING 2 -population is decreasing at a logarithmic rate -during the death phase, the number of deaths exceeds the number of new cells formed. Direct Measurement of Microbial Growth 4