BIO 326R Microbiology Lecture 7Outline of Last Lecture I. Metabolisma. Catabolic and anabolicII. Catabolic reactionsa. Exergonic and oxidativeIII. Anabolic reactionsa. Endergonic and reductiveb. Coupled reactionsIV. Enzymesa. Allosteric regulationb. Competitive inhibitor regulationOutline of Current Lecture I. Sources of energy in the cella. ATP and transmembrane ion gradients (proton motive foce)II. Electron source in the cella. Oxidative reactionsi. Coenzymes like NAD+ hold e- (NADH)III. How do bacteria make ATPa. Proton motive forceb. Substrate level phosphorylation (fermentation)i. Convert ADP to ATP with 4 stepsIV. GlycolysisThese 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.a. Uses same 4 stepsV. FermentationVI. RespirationCurrent LectureEnergy Sources in the cell- Two sourceso ATP and transmembrane ion gradients proton motive force (pmf) Ex: bacteria in the ocean (salt water) use Na+ gradients to produce energy ATP<-> pmf- Interchangeable—use electrons that come from an H protonElectron Source in the Cell- Oxidation reactions: dehydrogenase removes a hydrogen (a proton with one electron)- H atoms are transferred to coenzymes like NAD+ that can store that electrono Reductive poise of the cell NAD+ (proton), NADH (holds the Hydrogen; the electron), NAD(H) (sum ofNAD+ and NADH) NADP+, NADPH, NADP(H)- NAD vs. NADPo Specificity NADP to build (biosynthetic reactions) NAD to break down and hold electronso Ratio NAD(H)/NADP(H)= 10/1- It takes more NAD than NADP for a cell to growo Interchangeable—can make one with another NAD+ + ATP NADP+ (NAD Kinase) o NAD(H) energy (NAD/NADH) = >1o NADP(H) build (NADP/NADPH)= 0.005How is ATP made?- Proton motive force- Substrate level phosphorylation= fermentationo Convert ADP to ATPo Steps: Take organic substrate and phosphorylate with Pi (inorganic phosphate)- No energy input—phosphate is a low energy bond (need to make a high energy bond) Oxidize substrate to get energy by removing electrons (exergonic)energy release Trap released energy by converting low energy P to high energy Transfer high energy P to ADP and make ATPGlycolysis—follows the above steps twice)- Net 2 ATP, 2 NADH, and 2 pyruvate are made- Using this method for energy is inefficient—doesn’t get much energy, need lots of glucose to get a lot of energy this wayFermentation- Protons and electrons produced by oxidation of an organic substrate (usually carried as NADH) are used to reduce a second organic molecule (produced from the first)o After glycolysis, dump NADH back on pyruvate to make lactateo Problem: Regenerating NAD+ Consume large amounts of substrate (glucose)Respiration- ~30 ATP from 1 glucose molecule- Pmf is used to generate ATP, along with substrate level
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