BCHM 3050 1st Edition Exam 4 Study Guide Lectures 27 35 Lecture 27 March 25 What is the difference between a transition and transversionmutation Transversion purine replaced with pyrimidine and pyrimidine replaced with purine Transition mutation 80 of mutation replace purine with purine and pyrimidine with pyrimidine What is worse a frameshift mutation or a missense mutation A frameshift mutation is worse because it changes more than one amino acid while a missense mutation only changes one amino acid Lecture 28 March 27 How does UV radiation affect the production of Vitamin D and Folic acid Vitamin D production proportional to light penetration Folic acid Vitamin B9 destruction proportional to light penetration How did people come to adapt a lighter skin color When people with dark skin moved away from harsh sunlight they could not absorb the little bit of sunlight needed to aid them with melanin Over time the people adapted to have lighter skin color in order to be able to obtain melanin Lecture 29 April 1 What is an epimer What are some examples Epimers different at only one carbon atom ex glucose Glucose and Manmose are epimers around carbon atom 2 Glucose and Galactose are epimers around carbon atom 4 What is a reducing sugar What is an example Reducing sugar galactose has a free OH group when a part of lactose This means that the OH group at carbon 1 in galactose ring can form more glycosidic bonds and react with other molecules Therefore Lactose is a reducing sugar Lecture 30 April 3 What is cellulose Cellulose a polysaccharide that functions in plant cell wall structure It is composed of betaglucose units that create a 3D mesh connected by hydrogen bonds Humans do not have the enzyme to digest cellulose Describe the very first step in glycolysis As soon are we consume glucose the body attacks it Be able to write out this pathway from memory Hexokinase adds a phosphate group to glucose glucose 6 phosphate This is an energy investment phase because ATP is invested When hexokinase meets glucose it is committing glucose to go through glycolysis Exothermic reactions are spontaneous irreversible Glucose 6 phosphate inhibits regulates hexokinase Lecture 31 April 6 Compare glucokinase to hexokinase Glucokinase is the sister enzyme to hexokinase Glycogen alpha 1 4 Glucokinase works in the liver and is a much higher pay in value Km of the two enzymes is vastly different hexokinase is 10 times lower means that it has a better affinity Hexokinase is the enzyme that usually carrier out glycolysis Too much glucose use of glucokinase Insulin is needed to activate glucokinase Describe the energy payoff stage in glycolysis DHAP is converted to Gald 3P Two Gald 3P is oxidized to pyruvate 2 NADH and 4 ATP are produced NADH is generated with dehydrogenase NAD is getting reduced to NADH Dehydrogenase also carried out phosphorylation so technically it is also a kinase Lecture 32 April 8 In general describe the citric acid cycle Pyruvate is a 3 carbon atom containing molecule 2 molecules of pyruvate at start 4 NADH 1 FADH2 3 CO2 GTP are the products of this reaction Enzyme converts pyruvate into acetyl coA which carries out the Krebs cycle pyruvate itself doesn t actually carry out the krebs cycle Pyruvate dehydrogenase is the enzyme that catalyzes the step before the start of the Krebs cycle Inside of the mitochondria is the matrix where pyruvate dehydrogenase is found pyruvate processing pyruvate loses 2 CO2 forming acetyl coA 2 molecules of NADH formed Start with 6 carbon glucose in glycolysis all carbon atoms are broken down and released at 6 CO2 molecules What enzymes are involved in the citric acid cycle List them in the order in which they are used in the cycle Pyruvate dehydrogenase Citrate synthase Aconitase Isocitrate dehydrogenase aKetoglutarate dehydrogenase Succinyl CoA synthetase Succinate dehydrogenase Fumarase Malate dehydrogenase Lecture 33 April 10 What is reduction potential Reduction potential the potential of a compound to get reduced Higher the reduction potential more likely to attract electrons and get reduced good oxidizing agent Good oxidizing agents get reduced themselves and help other molecules to get oxidized positive reduction potential Idea of electron transport chain is that electrons are going from one chemical to another chemical always go from low reduction potential to a high reduction potential Give an overview of the electron transport chain Electrons come from NADH which was generated during glycolysis and krebs cycle electrons flow through all 4 complexes oxygen accepts electrons at the end to form water Transfer of electrons generates ATP Lecture 34 April 13 What does each of the four complexes of the electron transport chain do Complex 1 oxidized NADH back to NAD o Complex 1 is rich in flavoproteins and iron sulfur proteins and ubiquinome never find cytochromes or copper in Complex 1 Complex 2 succinate dehyrogenase generates FADH2 which gives up its electrons to other proteins o succinate dehydrogenase complex FADH2 passes electrons to Fe S protein end up giving protons to CoQ receives electrons from FADH2 Complex 3 cytochromes gives up and takes electrons o contains Fe S proteins and cytochromes no flavoproteins o Electrons go to cytochrome C outside of complex 3 Complex 4 cytochrome c oxidase is conserved across species o has copper that accepts the electrons and donates them to oxygen to reduce it to water What are some poisons that serve as inhibitors of respiratory electron transport Antimycin is an anti fungal blocks electron transfers within complex 3 Carbon monoxide blocks the transfer of electrons from copper to oxygen Cyanide blocks electron transfer from copper to oxygen also Barbituate truth serum inhibits transfer of electrons from Complex 1 to Complex 2 Lecture 35 April 15 What is an alternate oxidase in plants Skunk Cabbage smells due to heavy smell from sulfur They have complex 1 and 2 but not complex 3 or 4 CoQ gives enzymes directly to oxygen so we cannot inhibit this pathways with cyanide o They have an alternate oxidase An alternate oxidase lesser ATP produce and the extra energy is lost as heat increase the temperature so these plants always feel warm About how many molecules of ATP are harvested for each molecule of NADH and FADH2 For every NADH that gives up its electrons harvest about 2 5 molecules of ATP For every FADH2 that gives up its electrons harvest about 1 5 ATP molecules
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