Chapt08 lecture

Metabolism ,[object Object],[object Object],[object Object],[object Object],[object Object],Glucose CATABOLISM ANABOLISM ANABOLISM ANABOLISM Relative complexity of molecules + Bacterial cell Macromolecules Nutrients from outside or from internal pathways Pyruvate Acetyl CoA Glyceraldehyde-3-P Amino acids Sugars Nucleotides Fatty acids Proteins Peptidoglycan RNA + DNA Complex lipids Glycolysis Krebs cycle Respiratory chain Fermentation Yields energy Building blocks Precursor molecules ATP NADH Uses energy Uses energy Uses energy; some assembly reactions occur spontaneously. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Enzymes ,[object Object],[object Object],[object Object],[object Object],[object Object],E Products Substrate (S) Enzyme (E) Does not fit ES complex Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Reaction Energetics ,[object Object],[object Object],[object Object],[object Object],Energy State of Reaction Energy of activation in the absence of enzyme Energy of activation in the presence of enzyme Progress of Reaction Final state Products Initial state Reactant Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Enzyme Pathways ,[object Object],[object Object],[object Object],[object Object],A B C D E U V W X Z Y O 2 O O 1 M N P Q R M A B C N X Y Z Multienzyme Systems Linear Cyclic Example: Glycolysis Example: Krebs cycle Tinput S product Example: Amino acid synthesis Convergent Branched Divergent Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Strategy of Metabolism ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],O HO H CH 2 OH 6 H OH H H OH C CO 2 C C C C C 5 4 3 2 1 3 H OH Energy Level Of Chemical Compound O 1 2 The energy in electrons and hydrogens is captured and transferred to ATP. ATP is spent to drive the thousands of cell functions. ATP used to perform cellular work Hydrogen ions with electrons Hydrogen ions with electrons ATP Progress of Energy Extraction over Time These reactions lower the available energy in each successive reaction, but they effectively route that energy into useful cell activities. Low High Hydrogen ions with electrons Glucose 2H + + 2e – O 2 H 2 O O 1 – 2 + End products Final electron acceptor Glucose is oxidized as it passes metabolic pathways, resulting in the removal of hydrogens and their accompanying electrons. During part of these pathways, the glucose carbon skeleton is also dismantled, giving rise to the end product CO 2 . Oxidation of glucose by means of enzyme-catalyzed pathways 4 In aerobic metabolism, the electrons and hydrogen ions generated by the respiratory pathways combine with oxygen to produce another rend product, water. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. ― ― ― ―

Key Intermediates (building blocks) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Concept Check ,[object Object],[object Object],[object Object],[object Object],[object Object],Energy State of Reaction Energy of activation in the absence of enzyme Energy of activation in the presence of enzyme Progress of Reaction Final state Products Initial state Reactant Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

ATP ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],2H 2e: N NH 2 O H C C C C C C P P N H C C C C C C O P P H H + Oxidizednic otinamide Reducednic otinamide NAD From substrate Adenine Ribose NH 2 NADH + H + Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Substrate Level Phosphorylation ,[object Object],[object Object],[object Object],[object Object],[object Object]

Oxidation/Reduction ,[object Object],[object Object],[object Object],2 8 1 2 8 2 8 7 2 8 8 1 2 Reduced anion Cl Na Cl Na Reducing agent gives up electrons. Oxidizing agent accepts electrons. Oxidized cation Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

NAD ,[object Object],[object Object],[object Object],[object Object],2H 2e: N NH 2 O H C C C C C C P P N H C C C C C C O P P H H + Oxidizednic otinamide Reducednic otinamide NAD From substrate Adenine Ribose NH 2 NADH + H + Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Glycolysis (Stage 1) Energy is spent in the front end to get more later. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Glucose Glucose 6-Phosphate A A Fructose 6-Phosphate A A Fructose 1,6-Biphosphate

Glycolysis (Stage 2) Splitting into two molecules doubles the reactants. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fructose 1,6-Biphosphate PGAL & DHAP + 1,3 Bisphospho- glycerate 2X 2 NAD + 2 NADH + 2H + 2

Glycolysis (Stage 3) Break-even point using substrate-level phosphorylation. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1,3 Bisphospho- glycerate 2X 2X 2X A A 2X 3 PGA 2X 2 PGA

Glycolysis (Stage 4) The payoff - a net yield of ATP by substrate level phosphorylation Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2X Phosphoenolpyruvate 2 PGA 2X 2X A A 2X 2X Pyruvate

Concept Check ,[object Object],[object Object],[object Object],[object Object],[object Object]

Glycolysis Summary ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

The Kreb’s Cycle ,[object Object],C C H 2 H C HO C H 2 CO 2 C C H + C OO – C H 2 C H 2 C O C OO – C OO – C H 2 H O NAD + CO 2 C H 2 C C C O O S O C S C H 3 C C H 2 C C H 2 Acetyl CoA Isocitric acid 8 8 1 2 3 4 5 5 6 7 7 6 3 2 PO 4 –3 C O C H 3 O C C o A C H 2 C C H H C C C C H C C C C H 2 O C O – O – + H + + H + + H + + C C C H 2 H C CO 2 ATP ADP Succinyl CoA CoA CO 2 NAD H NAD + An additional NADH is formed when malic acid is converted to oxaloacetic acid, which is the final product to enter the cycle again, by reacting with acetyl CoA. Fumaric acid reacts with water to form malic acid. Succinic acid loses 2 Hand 2e – , yielding fumaric acid and generating FADH 2 . Succinyl CoA is converted to succinic acid and regenerates CoA. This releases energy that is captured in ATP. a-ketoglutaric acid loses the second CO 2 and generates another NADH + plus 4C succinyl CoA. Isocitric acid is converted to 5C a-ketoglutaric acid, which yields NADH and CO 2 . Citrate changes the arrangement of atoms to form isocitric acid. The 2 Cacetyl CoA molecule combines with oxaloacetic acid, forming 6C citrate, and releasing CoA. a-ketoglutaric acid NAD H NAD + OO – OO – Citric acid CoA OO – OO – OO – CoA Pyruvic acid From glycolysis NAD H Oxaloacetic acid OO – OO – H 2 O Malic acid OO – HO OO – NAD + NAD H Krebs Cycle OO – OO – FADH 2 FAD OO – OO – Fumaric acid Succinic acid AEROBIC RESPIRATION ANAEROBIC RESPIRATION FERMENTATION Glycolysis Glycolysis Glycolysis Glucose Glucose Glucose ATP NADH ATP NADH ATP NADH 2pyruvate (3C) (6C) 2pyruvate 2pyruvate (6C) (3C) (3C) (6C) CO 2 CO 2 Acety lCoA Acetyl CoA Fermentation FADH 2 NADH ATP Krebs CO 2 Electrons Electron transport ATP produced = 38 O 2 is final electron acceptor. FADH 2 NADH Krebs ATP CO 2 Electrons Electron transport ATP produced = 2 to 36 ATP produced =2 Lactic acid Acetaldehyde Ethanol Or other alcohols, acids, gases An organic molecule is final electron accept or (pyruvate, acetaldehyde etc.). Non oxygen electron acceptors (examples: SO 4 2–, NO 3 –, CO 3 2– ) 1 4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Kreb’s Cycle Summary ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Regenerating NAD + ,[object Object],[object Object],[object Object],[object Object]

Fermentation ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Fermentation ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],C C O O C H H H OH C C H H H H H C C O H H H H C C C H H H H O H O O H System: Homolactic bacteria; human muscle Glucose System: Yeasts Glycolysis Lactic acid Ethyl alcohol Pyruvic acid OH NADH NAD H NADH NAD NAD CO 2 Acetaldehyde O 2 is final electron acceptor. ATP produced = 38 ATP produced = 2 to 36 ATP produced = 2 Non oxygen electron acceptors (examples: SO 4 2–, NO 3 –, CO 3 2– ) An organic molecule is final electron accept or (pyruvate, acetaldehyde, etc.). AEROBIC RESPIRATION Glycolysis Glucose ATP NADH 2pyruvate (3C) (6C) CO 2 Acety lCoA FADH 2 NADH ATP Krebs CO 2 Electrons Electron transport ANAEROBIC RESPIRATION Glycolysis Glucose ATP NADH 2pyruvate (3C) (6C) CO 2 Acety lCoA FADH 2 NADH ATP Krebs CO 2 Electrons Electron transport FERMENTATION CO 2 Glycolysis Glucose ATP NADH 2pyruvate Lactic acid Ethanol Or other alcohols, acids, gases Acetaldehyde (6C) (3C) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Redox Potential Energy ,[object Object],[object Object],[object Object],[object Object],[object Object]

Electron Transport System ,[object Object],[object Object],[object Object],[object Object],H H H H H H H H H H H H H H H H H H H H Cell wall Cytochromes Cytoplasm Cell membrane with ETS ATP ADP ATP synthase Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Anaerobic Respiration ,[object Object],[object Object],[object Object],[object Object],[object Object]

Aerobic Respiration ,[object Object],[object Object],[object Object],[object Object],[object Object]

Chemiosmosis ,[object Object],[object Object],[object Object],[object Object],H + F 0 e – H H O O H + 1 / 2 O 2 (c) The distribution of electric potential and the concentration gradient of protons across the membrane drive the synthesis of ATP by ATP synthase. The rotation of this enzyme couples diffusion of H + to the inner compartment with the bonding of ADP and P i . The final event of electron transport is there action of the electrons with the Hand O 2 to form metabolic H 2 O. This step is catalyzed by cytochrome aa 3 . H + H + H + H + H + ATP ADP + P i ATP synthase H + Outer compartment e – Cytochrome aa 3 H + H + H + H + H + H + H + H + H + H + H + H + Inner compartment Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Aerobic Respiration Yield ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Amphibolism CO 2 H 2 O Glycolysis Anabolism Catabolism Simple products Metabolic pathways Building block Macromolecule Cell structure Chromosomes Enzymes Membranes Cell wall Storage Membranes Storage Lipids Fats Starch Cellulose Proteins Nucleic acids Nucleotides Amino acids Carbohydrates Fatty acids Beta oxidation Deamination GLUCOSE Pyruvic acid Krebs cycle Acetyl coenzyme A NH 3 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Oxygenic Photosynthesis ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],½ O 2 2e – 2H + P i Photolysis Electron carriers Calvin Cycles A B D C N N N Mg N H + H + H + H + H + H + H + 1 2 3 4 5 6 (a) A cell of the motile alga Chlamydomonas, with a single large chloroplast (magnified cut away view). The chloroplast contains membranous compartments called grana where chlorophyll molecules and the photosystems for the light reactions are located. (b) A chlorophyll molecule, with a central magnesium atom held by a porphyrin ring. Flagellum Nucleus Cell wall Chloroplast Photons Granum Stroma Thylakoid membrane NADPH ATP ADP + NADP 2e – P700 Electron carriers Photosystem I 2e – P680 Photosystem II H 2 O ATP synthase Proton pump Interior of granum (c) The main events of the light reaction shown as an exploded view in one granum. When light activates photosystem II, it sets up a chain reaction, in which electrons are released from chlorophyll. 1 2 3 4 5 6 Both NADPH and ATP are fed into the stroma for the Calvin cycle. The final electron and H + acceptor is NADP, which receives these from photosystem I. Pumping of H + into the interior of the granum produces conditions for ATP to be synthesied. The empty position in photosystem II is replenished photolysis of H 2 O.Other products of photolysis are O 2 and H + These electrons are transported along a chain of carriers to photosystem I. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Anoxygenic Photosynthesis ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Calvin Benson Cycle ,[object Object],[object Object],[object Object],[object Object],P P P P P P P P P P P P P P H H Splitting ADP ATP × 2 ADP ATP Series of 7 Carbon and 5 Carbon intermediates Ribulose-1,5-bisphosphate 5Carbon CO 2 6 Carbon intermediate NADPH × 2 NADP Glyceraldehyde-3 phosphate Glucose Fructose intermediates 1,3-bisphosphoglyceric acid Calvin Cycle 3-phosphoglyceric acid Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Chapt08 lecture

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (19)

Similaire à Chapt08 lecture

Similaire à Chapt08 lecture (20)

Dernier

Dernier (20)

Chapt08 lecture

Notes de l'éditeur