Module 2- Microbiology Portage Learning Questions and Answers 100% Pass

Module 2- Microbiology Portage Learning Questions and Answers 100% Pass cellular metabolism a controlled set of biochemical reactions that occur in living organisms to maintain life Enzymes a protein, or group of proteins, that speed up (catalyze) chemical reactions Cofactors a small chemical component, usually metal ions, that assist and regulate enzymes during the catalysis reactions. enzymes break down proteins into what: amino acids enzymes break down lipids into what: glycerrol/fatty acids enzymes break down polysaccharides into what: monosaccharides Anabolism the building up of macromolecules from smaller molecular units into larger complexes. Catabolism Metabolic pathways that break down molecules, releasing energy. Phototrophs organisms that get energy from photons of light to generate ATP from ADP Chemotrophs organisms that obtain energy from chemicals found in the environment Organotrophs chemotrophs that remove electrons from organic compounds (such as glucose) Lithotrophs chemotrophs that remove electrons from inorganic molecules (such as elemental sulfur) Heterotrophs a microorganism that cannot make its own food and must get carbon from organic molecules (ie. sugars) autotrophs Organisms that make their own food and derive their carbon from inorganic molecules (most often CO2) Phosphorylation The transfer of a phosphate group, usually from ATP, to a molecule. Nearly all cellular work depends on ATP energizing other molecules by phosphorylation. 3 Types of phosphorylation reaction that generates ATP: 1. Photophosphorylation - the use of light energy / 2. Substrate-level phosphorylation - the phosphoryl (PO3) group of a chemical compound is transferred and donated directly to ADP / 3. Oxidative phosphorylation - the energy released by the chemical oxidation of nutrients is used to reform ATP glucose metabolism The process by which cells commonly obtain energy by breaking the chemical bonds of glucose molecules and use this energy to form ATP. Yields up to 38 ATP and involves three distinct transitions. steps of glucose catabolism 1. Glycolysis: the breakdown of glucose to pyruvate to yield energy. Yields 2 ATP 2. Either fermentation or respiration yields 2 additional molecules of ATP 3. Electron Transport Chain produces 34 ATP via an oxidative phosphorylation event at the plasma membrane Reactants Any molecules present and involved at the beginning of a chemical reaction. Located to the left of the reaction arrow when written out. Glycolysis The first step in releasing the energy of glucose, a single glucose molecule is broken down into two pyruvate molecules. As a result of this process, NADH and ATP are also produced. Can occur in the presence or absence of oxygen. fermentation (anaerobic respiration) the breakdown of sugars without the use of oxygen, regenerate NAD+ so glycolysis can continue cellular respiration Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen Krebs Cycle (Citric Acid Cycle) second stage of cellular respiration in eukaryotes, takes place in matrix of mitochondria, - Pyruvic acid combines with coenzyme A to form Acetyl-CoA which enters Krebs cycle - in matrix of mitochondria - each turn of Krebs cycle produces 1 molecule of ATP, 1 molecule of FADH2, and 3 molecules of NADH (multiply to 2 since there are two Pyruvates electron transport chain third stage of cellular respiration NADH is oxidized to form NAD+ and FADH2 is oxidized to form FAD. As the electrons from these carriers move down the ETC, energy is released. This energy pumps H+ ions across the membrane, creating a proton gradient which is used for chemiosmosis and generates ATP. proton-motive force The potential energy stored in the form of an electrochemical gradient, generated by the pumping of hydrogen ions across biological membranes during chemiosmosis. beta oxidation A metabolic sequence that breaks fatty acids down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate AcetylCoA, which enters the Krebs cycle. Photosynthesis Conversion of light energy from the sun into chemical energy. Chloroplast An organelle found in plant and algae cells where photosynthesis occurs Photophosphorylation The light reaction of photosynthesis, and is the process of converting light energy into chemical energy to be used by the cell in the forms of ATP and NADPH., occurs in the membrane Calvin Cycle the dark reaction of photosynthesis (light independant) and involves the ability of a microorganism to use the ATP and NADPH generated in the light reaction to convert CO2 and H2O into organic carbon compounds and useful carbohydrates, requires 6 turns to generate one molecule of glucose Substrate The reactant on which an enzyme acts on. Protease enzyme that catalyzes the breakdown of proteins Lipase pancreatic enzyme necessary to digest fats Catalase An enzyme produced in all cells to decompose hydrogen peroxide, a by-product of cell respiration. Without catalase, a cell would be unprotected from oxidative damage by reactive oxygen species (ROS) and could not survive. six major categories of enzymes Hydrolase - catalyzes hydrolysis - the cleavage or breaking apart of chemical bonds by the addition of water. (Ie. A-B + H2O -> A-OH + B-H) Isomerase - promotes intramolecular rearrangements by altering bonds and/or confirmations within the same molecule producing a different molecule having the same molecular formula, aka an isomer. (Ie. A-B -> B-A) Ligase - causes covalent bonds to be formed between molecules (ie. A + B -> A-B) Lyase - causes the cleavage (break) of bonds by means other than hydrolysis or oxidation (A-B -> A + B) Oxidoreductase - catalyzes the transfer of electrons from the reductant (electron donor) to the oxidant (electron acceptor). (A- + B -> A + B) Transferase- acts to transfer a specific functional group from one molecule to another (Ab + C -> A + Cb) Hydrolase an enzyme that catalyzes hydrolysis - the cleavage or breaking apart of chemical bonds by the addition of water. ( ie. A-B + H2O -> A-OH + B-H) Isomerase an enzyme that rearranges bonds within a molecule to form an isomer ( ie. A-B -> B-A) Ligase an enzyme that causes covalent bonds to be formed between molecules (ie. A + B -> A-B) Lyase an enzyme that cleaves the bonds of atoms without hydrolysis ( ie. A-B -> A + B) Oxidoreductase an enzyme that catalyzes the transfer of electrons from the reductant (electron donor) to the oxidant (electron acceptor). ( ie. A- + B -> A + B) Transferase enzymes acts to transfer a specific functional group (ie. the amino or phosphate group) from one molecule to another (Ab + C -> A + Cb) Active site of an enzyme the region of an enzyme that attaches to a substrate ATP has the energy to ________ , while ADP has the capacity to ________ energy. donate, accept What is the difference between catabolism and anabolism? Catabolism is the process of breaking down larger molecules into useful energy sources. Anabolism is the building up or biosynthesis of macromolecules from smaller molecular units into larger complexes, most often associated with cellular growth and repair. Chemotrophs utilize which form of phosphorylation? Chemotrophs use oxidative phosphorylation (as opposed to photo or substrate-level phosphorylation). Oxidative phosphorylation utilizes the energy released by the chemical oxidation of nutrients to reform ATP. Excluding sugars, what are the other sources of energy? Which is highest in energy? Proteins, lipids, polysaccharides. Lipids are highest in energy, can generate 48 ATP to glucose's 38. In the absence of sugars, are entirely different metabolic pathways used to process alternative sugar sources (fructose or lactose)? No. Additional enzymatic steps are simply required at the beginning of catabolism to convert complex sugars into the usable forms of either glucose or a glucose intermediate (glucose-6-phosphate). In what organelle does photosynthesis take place? Chloroplast In photophosphorylation, the light reactions always occur where? The process of converting light energy into chemical energy (photophosphorylation) always occurs in the membrane. Similar to the electron transport chain, one of its main functions is to generate a proton concentration gradient to generate ATP. What are the byproducts of light reactions used for in dark reactions? The byproducts of light reactions are ATP and NADPH. They are used in dark reactions to convert H20 and CO2 into organic carbon molecules and useful carbohydrates. Calvin Cycle reaction (written out equation) 6 CO2 + 18 ATP + 12 NADPH + 12 H2O -> C6H1206 + 18 ADP + 12 NADP+