Metabolism Life is a bag of biochemistry 1 Chloroplasts and mitochondria Heat Carbohydrate O 2 CO 2 + H 2 O Heat Chloroplast Mitochondria 2 What is food? Proteins - polymers of amino acids Carbohydrates polymers of sugars Fats (lipids) polymers of fatty acids and glycerol. Vitamins and trace elements 3 1
Digestive enzymes Proteins proteases Trypsin, chymotrpsin, carboxypeptidases, aminopeptidase, etc. Carbohydrates carbohydrases Amylase, cellulase, lactase, glucosidase, etc. Fats (lipids) lipases Pancreatic lipase, esterases, phospholipase, etc. 4 Intracellular digestion Phagosome Food vacuole Exocytosis Lysosomes Phagocytosis Golgi complex 5 Extracellular digestion Secretion of digestive enzymes Secretory vesicle Golgi complex Gut lumen Gut wall 6 2
What s energy? Light, heat and electrical energy Kinetic energy Potential energy Chemical energy 7 Energy flow laws of thermodynamics 1 st law Can t be created or destroyed 2 nd law Entropy law, some is always lost 8 Enzymatic catalysis (Building and breaking covalent bonds) Active site Active site Substrate 9 3
Enzymatic catalysis Internal Energy Activation energy without enzyme With enzyme Energy release of reaction Reaction progress 10 AMP,, & <-> 7300 cal/mol <-> AMP 7300 cal/mol O O O O - P O P O P O O - O - O - CH2 OH O OH N N NH 2 N N 11 The cycle Energy released from reactions exergonic Energy released for reactions endergonic 12 4
Coupled reactions Substrate A Product B Energy requiring (Endergonic, anabolism) Enzyme A P P P P P Energy producing (Exergonic, catabolism) Enzyme B Product B Substrate A 13 Electron transport system 14 Chemioosmosis 15 5
Cellular respiration Protein: Amino acids Pyruvate Charbohydrates: Glycolysis Acetyl Kreb s Sugars CoA Cycle e - Fats: Glycerol Fatty acids Electron transport chain Extracellular Intracellular Inside the mitochondria Glycolysis 2 2 Glucose Free energy Fructose- 1,6-diphosphate Glycolysis C3 C3 PGAL Pyruvic acid Pyruvic acid 17 Redox pair Oxidized Reduced H O C NH 2 N + 2H + 2e - H H +.. N O C H NH 2 R R 18 6
Cellular respiration Protein: Amino acids Pyruvate Charbohydrates: Glycolysis Acetyl Kreb s Sugars CoA Cycle e - Fats: Glycerol Fatty acids Electron transport chain Extracellular Intracellular Inside the mitochondria Mitochondrial structure 20 Acetyl Coenzyme A (Acetyl CoA) Pyruvate + Coenzyme A Acetyl coenzyme A Pyruvate O dehydrogenase O CH 3 -C-COO - + CoA-SH CH 3 -C-S-CoA + CO 2 NAD + 21 7
Kreb s cycle (Citric acid cycle) Oxaloacetate C C C C H 2 O Acetyl CoA C C FADH 2 FAD+ C C C C Succinic acid GTP CoA Citric Acid C C C C C C CO 2 C C C C C a-ketoglutaric acid CO 2 C H 2 O C GDP Oxidative phosphorylation H + H + H + FADH 2 FAD+ Pyruvic acid Acetyl CoA Kreb s Cycle CO 2 e - O 2 H + H 2 O http://www.genome.ad.jp/kegg/pathway/map/map00190.html 23 Glycolysis (anaerobic) 2 2 Glucose Fructose- 1,6-diphosphate Free energy Glycolysis Pyruvic acid Lactic Acid Lactic Acid Pyruvic acid 24 8
Anaerobic vs. aerobic metabolism 1 M glucose = 686 Kcal 1 M = 7.3 Kcal Anaerobic respiration 2 14.6 Kcal 14.6/686 = 2% Efficiency Aerobic respiration 38 277.4 Kcal 277.4/686 = 40% Efficiency 18 X more energy! 25 Cellular respiration Protein: Amino acids Pyruvate Charbohydrates: Glycolysis Acetyl Kreb s Sugars CoA Cycle e - Fats: Glycerol Fatty acids Electron transport chain Extracellular Intracellular Inside the mitochondria Energy stores 10 9 molecules of in a typical cell Replaced every 1-2 minutes Glycogen Complex polysaccharide in cytoplasm Humans have a one day reserve Fats Packs the same calories as glycogen in 15% mass Humans have a 30 day reserve 27 9
Chlorophyl a and b 28 Chloroplast structure 29 Cyclic electron pathway 30 10
Non-cyclic electron pathway 31 Chloroplast structure and function 32 33 11
Light independent reactions C Ribulose 1,5 biphosphate C C C C C C C C C C C C C C Glyceraldehyde 3-phosphate 34 C, C 3 4 and CAM plants 35 Photosynthesis 6 CO 2 + 12 H 2 0 + light C 6 H 12 O 6 + 6 H 2 0 + 6 CO 2 36 12