BCHM 307 1st Edition Lecture 29 Outline of Last Lecture I Thermodynamics A Endothermic Vs Exothermic B Gibbs Free Energy C Change in Free Energy II Change in Free Energy under Standard Conditions III ATP Hydrolysis Outline of Current Lecture I Catabolism vs Anabolism II Redox Reactions A FAD and FMN B NAD and NADP III ATP Synthesis IV ATP as Energy Current Lecture This 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 energy These 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 high energy 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 used and resynthesized Enzymes that catalyze the biological redox reactions will use molecules called coenzymes to 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 another
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