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Be late. Mobile phone rings during class. Chat during class. Dr Lihong (立红) Xu( 徐). Prof of Biochemistry and Molecular Biology 生物 化学 与 分子 生物学 教授. xulihong@zju.edu.cn. √. I. Biomolecules. √. II. Enzymes. III. Metabolic pathways, their regulation and metabolic interrelationships.
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Be late Mobile phone ringsduring class Chat during class
Dr Lihong(立红) Xu(徐) Prof of Biochemistry and Molecular Biology 生物化学与分子生物学教授 xulihong@zju.edu.cn
√ I. Biomolecules √ II. Enzymes III.Metabolic pathways, their regulation and metabolic interrelationships IV. Hormones V. Fat soluble and water soluble vitamins VI. Hematic Biochemistry VII. Molecular Biology
长城 西湖
N2 We are here. nitrogen-fixing bacteria denitrifying bacteria NH3 Urea nitrifying bacteria mammals animals plants NO3- NO2- Amino acids plants Cycling of nitrogenin the biosphere
We are here. photosynthetic(autotrophic) O2, organic products glucose heterotrophic CO2 Cycling of carbon dioxide and oxygen between the autotrophic(photosynthetic) and heterotrophic domain in the biosphere.
Phototrophs, an organism that can use the energy of light to synthesize its own fuels from simple molecules such as CO2, O2, and H2O, as distinct from a chemotroph. photosynthesis Autotrophs, an organism that can synthesize its own complex moleculesfrom very simple carbon and nitrogen sources, such as CO2and NH3. Can we do these?
We can eat. We must eat. Chemotroph, an organism that obtains energy by metabolizing organic compounds derived from other organisms. We, animal, live on Phototrophs and Autotrophs. HOW do we get the energy and the building blocks of macromolecules?
Metabolic pathways, their regulation • and metabolic interrelationships III-I Metabolism III-II Carbohydrate metabolism III-III Lipid metabolism III-IV TCA cycle and biological oxidation III-V Protein turnover and amino acid metabolism ; Nucleotide metabolism III-VI Regulation of the metabolic pathways
Digestion and absorption of dietary carbohydrates Pathways of glucose metabolism: glycolysis Pentose phosphate shunt Gluconeogenesis Glycogenolysis, glycogenesis Galactose and fructose metabolism Glycogen storage disease Inborn errors of glucose metabolism Regulation of glucose metabolism. general concepts and characteristics of metabolic pathways. III-I Metabolism III-II Carbohydrate metabolism III-III Lipid metabolism III-IV TCA cycle and biological oxidation III-V Protein turnover and amino acid metabolism ;Nucleotide Metabolism III-VI Regulation of the metabolic pathways Digestion and absorption of dietary fats. Biosynthesis and degradation of fatty acids, phospolipids and triacylglycerols Biosynthesis of cholesterol, chemistry and metabolism of lipoproteins. Hyperlipoproteinemias Lipid storage disease. Ketone bodies: their synthesis, utilization and conditions leading to ketoacidosis, prostaglandin. Digestion and absorption of dietary protein General reactions, transamination, its metabolic and diagnostic significance Disposal of amino acid nitrogen and detoxication of urea Metabolic fate of amino acid carbon skeleton Sulphur containing amino acids In born errors of branched chain and aromatic amino acids Important amino acid derivatives. Nucleotide metabolism Carbohydrate, lipid and amino acid metabolism Interlinks between these pathways. Organ interrelationships in metabolism, Blood glucose regulation, and its impairment in diabetes mellitus. Metabolic adaptation in the fed state, fasting and prolonged starvation. Metabolic derangements and adaptations in diabetes mellitus.
III-I Metabolism III-II Carbohydrate metabolism III-III Lipid metabolism III-IV TCA cycle and biological oxidation III-V Protein turnover and amino acid metabolism III-VI Regulation of the metabolic pathways
III-I Metabolism general concepts and characteristics of metabolic pathways
what why Q A how Be sure to REMEMBER
Q Where do we get energy ? Where do we get building blocks of macromoleculestobuild ourself?
A We,human beings and animals ,obtain energy and building blocks of macromolecules from ENERGY –RICH MOLECULES, produced by autotrophs and phototrophs, as well as other chemotrophs nutrients vitamins protiens polysaccharides lipids minerals amino acids monosaccharides glycerol fatty acids Thousands of complex reactions
Certain compartment in the CELL Chemical reactions Catalyzed by enzymes Thousands of complex reactions Energy Building blocks Other molecules needed in the body To be alive How can the reactions happen?
In a reversible reaction, what will decide the direction of the reaction ? + A B C Cell, isothermal
Basic concepts Free energy (G) A thermodynamic quantity, whose change at constant pressure is indicative of the spontaneity of a process. Free-energy change (ΔG) The amount of free energy released (negative ΔG) or absorbed (positive ΔG) in a reactionat constant temperature and pressure.
Living organisms requirea continual input of FREE ENERGY The energy that cells can and must use is FREE ENERGY,
Q What does △G mean? A △G will determine whether the reaction will be spontaneous at constant temperature and pressure.
Units of energy (will be used in description of free energy) A calorie (cal) is equivalent to the amount of heat required to raise the temperature of 1 gram of water from 14.5°C to 15.5°C. A kilocalorie (kcal) is equal to 1000 cal. A joule (J) is the amount of energy needed to apply a 1-newton force over a distance of 1 meter. A kilojoule (kJ) is equal to 1000 J. 1 kcal = 4.184 kJ
Change in free energy (△G) during a reaction. favorable process unfavorable process A can be spontaneously converted into B B cannot be spontaneously converted into A
1. A reaction can occur spontaneously only if △ G is negative. Such reactions are said to be exergonic. 2. A system is at equilibrium and no net change can take place if △ G is zero. 3. A reaction cannot occur spontaneously if △ G is positive. An input of free energy is required to drive such a reaction. These reactions are termed endergonic.
Q How is the free energy inputted to drive a reaction with positive △G? A A thermodynamically unfavorable reaction can be COUPLED by a thermodynamically favorable reaction.
the chemical intermediate B, common to both reactions, couples the reactions. The overall free-energy change for a chemically coupled series of reactions is equal to the sum of the free-energy changes of the individual steps.
A thermodynamically unfavorable reaction can be DRIVENby a thermodynamically favorable reaction to which it is coupled. as long as overall △G is negative.
Q HOW does the cell use FREE ENERGY? Both chemotrophy and phototrophy (as well as autotrophy) transform the free energy into ATP and other energy-carrier compounds. A The cell uses ATP and other energy-carrier compounds , transformed from FREE ENERGY.
The First Law of Thermodynamics The energy can be neither creatednor destroyed. The amount of energy in the universe isconstant. The energy can be converted from one form into another.
Basic concepts ATP Adenosine triphosphate, ATP Adenosine diphosphate, ADP Adenosine monophosphate, AMP adenine adenosine
ATP is an energy-rich molecule because its triphosphate unit contains twophosphoanhydride bonds. phosphate group transfer potential phosphoanhydride bonds, high-energy phosphate bonds
A large amount of free energy is liberated when ATP is hydrolyzed to ADP + Pi or AMP + PPi exergonic
ATP-ADP cycle a fundamental model of energy exchange in biological system Motion, active transport, signal amplification, and biosynthesis can occur only ifATPis continually regenerated from ADP.
Q There are two ways to form ATP. A • Substrate Level Phosphorylation • Oxidative Phoshorylation
Q Is ATP the only energy-carrier compound ? A There are some phosphorylated compounds ranking to energy-carrier compounds, like……. (filled it by youself)
Basic concepts Phosphate group transfer potential The tendency of a phosphorylated molecule to undergo hydrolysis During its hydrolysis, energy is released. The phosphoryl transfer potential is an important form of cellular energy transformation.
ATP is not the only compound with a higy phosphoryl transfer potential. other energy-carrier compounds Glycolysis intermediate
Q Why isATP the most important energy-carrier compound ? A ATP is highly accessible for energy-requiring processes, called energy currency.
Some compounds have a higher phosphoryl transfer potential than that of ATP and can be usedto phosphorylate ADP to form ATP.
It is significant that ATP has a phosphate group transfer potential that is intermediate among the biologically important phosphorylated molecules. This intermediate position enables ATP to function efficiently as a carrier of phosphoryl groups.
Creatine phosphate is the major source of phosphoryl groups for ATP regeneration for a runner during the first 4 seconds of a 100-meter sprint The amount of ATP in muscle suffices to sustain contractile activity for less than a second. more efficiently more rapidly , Importance of ATP during exercise The ATP must be regenerated by metabolic pathways.
Q HOW is the free energytransformed intoATP andother energy-carrier compounds A The free energy is transformedinto ATP and energy-carrier compounds through metabolism of nutrient molecules.
Q HOW do we get building blocksof macromolecules for our body? A The build blocks is derivedfrom metabolism of nutrient molecules.
Basic concepts pathway is formed by the coupling of enzyme-catalyzedreactions such that the overall free energy of the pathway is negative. The product of one reaction is the substrate of subsequent reaction. Specific pathways constructed from individual reactionsmust satisfy minimally two criteria: enzyme • the individual reactions must be specific. • the entire set of reactions that constitute the pathway must be thermodynamically favored. overall △G is negative
Basic concepts catabolic pathways serve to capture chemical energy in the form of ATP from the degradation of energy-rich fuel molecules, as well as extract reducing power from the diet, convert molecules in the diet into building blocks needed for the synthesis of complex molecules.
Basic concepts anabolic pathways combine small molecules to form complex molecules, in which the energy and reducing power are needed, supplied in the form of ATP and NADPH respectively. Anabolic reactions often involvechemical reduction.
Most catabolic pathways involve the oxidation of organic molecules coupled to the generation of both energy (ATP) and reducing power (NADH). In contrast, anabolic pathways generally involve theuse of both ATP and reducing power (usually in the form ofNADPH) for the production of new organic compounds. NADH NADPH