BCHM 307 1st Edition Lecture 29Outline of Last Lecture I. ThermodynamicsA. Endothermic Vs. ExothermicB. Gibbs Free EnergyC. Change in Free EnergyII. Change in Free Energy under Standard ConditionsIII. ATP HydrolysisOutline of Current Lecture I. Catabolism vs. AnabolismII. Redox ReactionsA. FAD and FMNB. NAD and NADPIII. ATP SynthesisIV. ATP as EnergyCurrent LectureThis lecture will continue on with the topic of thermodynamics. We will focus on what happens when ∆G is negative. This means the reaction will release energy. In biochemistry, this energy can be harnessed to do work. One form of this is catabolism. This occurs when breaking down large molecules into smaller ones. An example is breaking down starch to glucose. This reaction will ultimately release energy. Anabolism is the opposite of catabolism. This reaction requires an input of energy to work. It synthesizes large molecules from smaller ones. An example of this would be the synthesis of glucose from carbon dioxide. The focus of this class will be on catabolism, specifically oxidation-reduction (redox) reactions and phosphorylation reactions. Redox reactions involve transferring electrons. Oxidation refers to the loss of electrons. Reduction refers to the gain of electrons. Redox reactions require molecular partners to work. Let’s say we have two molecules, A and B. A is the more reduced compound starting out. It will give some of its electrons to compound B. As B gains these electrons, it become reduced. Conversely, as A loses these electrons it becomes oxidized. The compound that is oxidized is called the reductant. The compound that is reduced is called the oxidant. This transfer of energyThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.can be used in metabolism. Some common molecules that are involved in redox reactions are talked about below. FAD is one such molecule. This is the oxidized form. The reduced form is FADH2. FAD stands for Flavin adenine dinucleotide. FMN is another such molecule. This stands for Flavin mononucleotide in the oxidized form. The reduced form is FMNH2. A more commonly known redox pair is NAD+. This comes from the reduced form of NADH. Its full name is nicotinamide adenine dinucleotide. Another well-known one is NADP+, which comes from the reduced form of NADPH. This one’s full name is nicotinamide adenine dinucleotide phosphate. In a general sense, there is a way to tell the difference between the oxidized and reduced forms of these molecules when looking at their structures. The one with more double bonds is often the oxidized form. Let’s go back to looking more at ATP. ATP is known as the energy currency within biological cells. ATP is synthesized from ADP and inorganic phosphate. As this is anabolism, it require an input of energy to occur. The energy for this can be harnessed from a catabolism reaction or photosynthesis. Phosphoanhydride bonds are an example of bonds that contain highenergy. They are sometimes drawn with a ~ to denote this. ATP is not to be confused as an energy store form in cells. The storage forms are glycogen or fat in animals. In plants, the storage forms are sucrose or starch. ATP has a very high turnover rate, meaning it is rapidly usedand resynthesized. Enzymes that catalyze the biological redox reactions will use molecules called coenzymesto help trap the redox energy expelled during catabolism. This energy can then be used to create ATP. In metabolism, energy is often converted from one form to
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