Module 4 Overview of Metabolisms PDF

6|Metabolism FOOD/NUTRIENTS (Macromolecules) Building blocks: needed to make up cells Monosaccharides Amino acids Glycerol + Fatty acids...

6|Metabolism FOOD/NUTRIENTS (Macromolecules) Building blocks: needed to make up cells Monosaccharides Amino acids Glycerol + Fatty acids Muscle cells Protein + carbs Nucleotides + NA+ Lipids Bun = carbohydrates Cheese = protein + fats ⚡ ⚡ Energy ⚡ Patty = protein + fats ⚡ needed to Tomatoes = DNA & RNA perform “works” e.g. muscle movement, flagella rotation, active transport, biosynthesis!  Energy Kinetic energy, potential energy, chemical energy, free energy, exergonic reaction, endergonic reaction Energy flow through living system  1st Law of Thermodynamics: The total amount of energy is constant. Energy can be transferred or transformed, but cannot be created or destroyed. 2nd Law of Thermodynamics: Entropy of any isolated system always increase Every energy transfer involves some loss of energy in unusable form (e.g. heat), result in more disordered system (increase entropy) Why do we need energy? Energy is the ability to do work Cell use energy to perform… Chemical works (e.g. combine glucose to form polysaccharides) Transport works (e.g. active transport across cell membrane) Mechanical works (e.g. muscle contraction, flagella rotation) Types of energy Energy can be classified as kinetic or potential Objects in motion have kinetic energy (e.g. rapidly moving molecules in air 🡪 heat; light = electromagnetic radiation; a walking person) Objects that have the potential to move have potential energy Chemical energy Potential energy is associated with a matter’s location (e.g. monkey on a tree, ions on one side of the membrane), as well as a matter’s structure. 🡪 All molecules have energy Potential energy is stored in a molecule’s chemical bonds, and can be released as the bonds break. (Chemical energy) Chemical energy – Energy stored in chemical bonds (potential); energy released when bond break (kinetic) Chemical reactions are always accompanied by change in chemical energy Chemical reactions = making or breaking chemical bonds to rearrange atoms within molecules. Exergonic reaction Endergonic reaction Product has less energy than Product has more energy than reactant, free energy ΔG < 0 reactant, free energy ΔG > 0 Metabolism  Large, complex Large, complex organic molecules organic molecules Small, relatively simple molecules Monosaccharides Amino acids Glycerol + Fatty acids Nucleotides ⚡ ⚡ Energy ⚡ ⚡ ⚡ Energy ⚡ ⚡ ⚡ Catabolism Anabolism Metabolism = ALL chemical reactions in a cell Catabolic reactions Anabolic reaction Carbs, lipids, proteins are chemically Carbs, lipids, proteins are chemically broken down synthesized Free energy (ΔG) < 0, release energy Free energy (ΔG) > 0, require energy  Energy transferred in living systems Copyright © 2016 Pearson Education Inc. Oxidation is the removal of electrons from an atom/molecule. Oxidation reaction often produce energy Reduction is the gain of electrons for an atom/molecule Oxidation-reduction reaction (= redox reaction) is caused by the flow of electron from one molecule to another. Cells use oxidation-reduction reactions to transfer energy among molecules. Biological oxidation = dehydrogenation In biological systems, electron (e-) and proton (H+) are often removed at the same time. This is equivalent to removal of a hydrogen atom (which contains 1 proton and 1 electron). Therefore biological oxidation is also called dehydrogenation. In general, the more hydrogen a molecule contain, the higher its energy level is (e.g. lipids, starch)