9/14/16 1 Intestine OVERVIEW OF ENERGY AND METABOLISM When a - PDF document

9/14/16 1 Intestine OVERVIEW OF ENERGY AND METABOLISM When a person eats, blood glucose rises. Biochemistry MA MAINTAINING 2 Pancreas High blood glucose stimulates BL BLOOD the pancreas to release insulin. 1. The food we eat, (carbohydrates/’glucose’/sugar, Insulin GL GLUCOSE SE 3 lipids/fat, proteins), are our only source of energy Insulin stimulates the uptake of 5. Bio-Energetics & ATP HOM HOMEOS OSTAS ASIS glucose into cells and storage as glycogen in the liver and for doing the biological work of cells. Liver muscles. Insulin also stimulates the conversion of excess glucose into fat for storage. 2. All molecules (nutrient molecules included) have Fat cell Muscle 5.1) ADP , ATP and Cellular Respiration stored (potential) energy in the bonds between their 4 As the body's cells use glucose, blood levels decline. atoms. Pancreas 5 Low blood glucose stimulates the pancreas to release Glucagon 3. The energy that runs most biological systems on glucagon into the bloodstream. 6 Glucagon stimulates liver earth comes from solar energy cells to break down glycogen Glucose and release glucose into the Insulin blood. a 4. Plants trap solar energy via the metabolic reactions Glucagon Liver Glycogen of Photosynthesis by producing these molecules a The stress hormone 7 epinephrine and other hormones Prof. Dr. Klaus Heese Blood glucose begins to also bring glucose out of storage. rise. THREE BASIC USES OF NUTRIENTS ALL LIVING THINGS FROM BACTERIA TO ABSORBED BY THE DIGESTIVE SYSTEM HUMANS CONDUCT METABOLISM Metabolism is the ability to acquire and use energy from 1. Energy for immediate use by cells to conduct their the environment. normal metabolic processes (Muscle contraction, Metabolic processes are all the chemical reactions secretions, active transport) that occur in cells, tissues, organs, and organ systems. 2. Synthesize structural or functional molecules to Two Kinds of Metabolic Reactions: repair and replace cells. (Mitosis and Cytokinesis) 1. Catabolism = breakdown of large molecules into simple ones to produce energy (release energy). 3. Storage as glycogen or fat for later use as energy (nutrient reserves) 2. Anabolism = build large molecules from simple molecules (requires energy input). TW TWO BASIC SIC KIN INDS S OF CH CHEMICA ICAL REACTIO TIONS S METABOLIC TURNOVER AND CELLULAR ATP FO FOUND IN BIOLOGICAL SYSTEM PRODUCTION WHAT IS ATP? Energy used by all Cells Adenosine Triphosphate Organic molecule containing high- energy Phosphate bonds 1

9/14/16 HOW DO WE GET ENERGY FROM ATP? CHEMICAL STRUCTURE OF ATP WHAT DOES ATP DO FOR YOU? Adenine Base It supplies YOU with ENERGY! By breaking the high- energy bond between the last two phosphates in ATP 3 Phosphates Ribose Sugar HOW IS ATP RE-MADE? HOW DOES THAT HAPPEN? WHAT IS THE PROCESS CALLED? An Enzyme! HYDROLYSIS (adding H 2 O) The reverse of the previous process occurs. Another Enzyme is H 2 O used! ATP Synthetase CELLULAR RESPIRATION THE ADP-ATP CYCLE WHEN IS ATP MADE IN THE BODY? l Includes pathways that require During a Process called: oxygen ATP Cellular Respiration ATP-ase l Glucose is oxidized and O 2 is reduced Synthetase l Glucose breakdown is therefore an oxidation-reduction reaction l Breakdown of one glucose results in or: oxidative phosphorylation 36 to 38 ATP molecules 2

9/14/16 OVERALL EQUATION FOR WHAT TYPE OF PROCESS IS CELLULAR WHAT CARRIES THE ELECTRONS? RESPIRATION? CELLULAR RESPIRATION • An Oxidation-Reduction Process or NAD + (nicotinadenine • C 6 H 12 O 6 + 6O 2 dinucleotide) acts as RedOx Reaction the energy carrier NAD + is a coenzyme • Oxidation of GLUCOSE --> CO 2 + H 2 O • (e - removed from C 6 H 12 O 6 ) • It is reduced to NADH YIELDS when it picks up two • Reduction of O 2 to H 2 O (e - passed electrons and one hydrogen ion to O 2 ) 6CO 2 + 6H 2 0 + e - + 36-38 ATP ’ s ARE THERE ANY OTHER ELECTRON OTHER CELLULAR RESPIRATION FACTS WHAT ARE THE STAGES OF CARRIERS? CELLULAR RESPIRATION? l YES! Another Coenzyme! • Metabolic pathway that breaks down l FAD+ (Flavin carbohydrates • Glycolysis adenine • Process is exergonic as high-energy • The Krebs Cycle dinucleotide) glucose is broken into CO 2 and H 2 O l Reduced to • The Electron Transport Chain • Process is also catabolic because larger FADH 2 glucose breaks into smaller molecules SU SUMMARY Y OF GLUCOSE SE MET ETABOLISM SM Glycogenesis: The process by which glycogen is synthesized from OVERVIEW glucose; in which glucose molecules are added to chains of glycogen for storage. Glycogenolysis: Glycolysis (also known as "Glycogenlysis") is the break down of Fat glycogen to glucose-1-phosphate and glucose for ATP production. Gluconeogenesis (abbreviated GNG) is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as pyruvate, lactate, glycerol, and glucogenic amino acids; the process by which protein or fat is converted into glucose. 3

9/14/16 OVERVIEW: GLYCOLYSIS SUMMARY GLYCOLYSIS SUMMARY DIAGRAM OF THE PROCESS Occurs across Takes place in the Cytoplasm Cristae •Also produces 2 NADH and 4(2) ATP Anaerobic (doesn’t use Oxygen) • Pyruvate is oxidized to Acetyl CoA and CO 2 is Requires input of 2 ATP removed Occurs in Glucose split into two molecules of Cytoplasm Pyruvate or Pyruvic Acid Occurs in Matrix AT ATP PRODUCTION FROM CARBOHYDRAT ATES ATP PRODUCTION FROM CARBOHYDRAT AT ATES FERMENTATION Glycolysis Ø Occurs when O 2 is NOT present Formation of Acetyl-CoA Substrates required: Glucose, 2 ATP , 4 ADP , and 2 NAD + (anaerobic) Substrates required: 2 Pyruvic Acid Ø Called Lactic Acid fermentation in Intermediate Reactants: Glucose-6-phosphate, 2 NAD + muscle cells (makes muscles tired) Fructose-1,6 bisphosphate 2 Coenzyme A Ø Called Alcoholic fermentation in yeast Products: 2 molecules of Pyruvic Acid (produces ethanol) Products: 2 Acetyl-CoA 2 ATP (4) 2 NADH Ø Nets only 2 ATP 2 NADH 2 CO 2 ATP PRODUCTION FROM CARBOHYDRATES A LITTLE KREBS CYCLE HISTORY ATP PRODUCTION FROM CARBOHYDRATES Krebs cycle • Discovered by Hans Krebs cycle Krebs in 1937 • He received the Substrates required: 2 Oxaloacetic Acid Products: 2 Oxaloacetic Acid Nobel Prize in 2 Acetyl-CoA physiology / 6 NADH medicine in 1953 for 6 NAD+ his discovery 2 FADH 2 2 FAD • Forced to leave 2 GTP Germany prior to 2 GDP 4 CO 2 WWII because he Intermediate Reactants: Citric Acid was Jewish 4

9/14/16 KREBS CYCLE SUMMARY OVERVIEW OF THE KREBS CYCLE OVERVIEW OF THE KREBS CYCLE Ø Requires Oxygen (Aerobic) Ø Cyclical series of oxidation reactions that give off CO 2 and produce one ATP per cycle Ø Turns twice per glucose molecule Ø Produces two ATP Ø Takes place in matrix of mitochondria ATP NETS: 3NADH, 1ATP, 1FADH 2 , & 2CO 2 KREBS CYCLE SUMMARY WHERE DOES CELLULAR RESPIRATION TAKE PLACE? REVIEW OF MITOCHONDRIA STRUCTURE Ø Each turn of the Krebs Cycle also It actually takes place l Smooth outer in two parts of the cell: Membrane produces 3NADH, 1FADH 2 , and 2CO 2 l Folded inner Ø Therefore, for each Glucose membrane Glycolysis occurs in l Folds called Cristae molecule, the Krebs Cycle produces the Cytoplasm l Space inside cristae called the Matrix 6NADH, 2FADH 2 , 4CO 2 , and 2ATP Krebs Cycle & ETC take place in the Mitochondria ATP PRODUCTION FROM CARBOHYDRAT AT ATES ATP PRODUCTION FROM CARBOHYDRAT AT ATES OV OVERVIEW OF ELECTRON TRANSPORT SYSTEM Electron Transport Chain A series of Oxidative Phosphorylation reactions Electron Transport Chain Oxidation = the removal of electrons from a molecule and results in a decrease in the Substrates required: 10 NADH energy content of the molecule. Because most 2 FADH 2 biological reactions involve the loss of hydrogen atoms, they are called 6 O 2 dehydrogenation reactions. Reduction = the opposite of oxidation; the Products: 32 ATP addition of electrons to a molecule, and results in an increase in the energy content of the 6 H 2 0 molecule. 5

9/14/16 Overview of Cellular Respiration SUMMARY OF ATP PRODUCTION ELECTRON TRANSPORT CHAIN SUMMARY • 34 ATP produced • H 2 O produced • Occurs across Inner Mitochondrial membrane • Uses coenzymes NAD + and FAD + to accept e- from glucose • NADH = 3 ATP’s • FADH 2 = 2 ATP’s OV OVERVIEW: LIPID METABOLISM PROTEIN METABOLISM THE ROLE OF TH TH THE LIVER IN LIPID METABOLISM SM Deamination: removal of the amino group (NH 2 ) • Lipoproteins: surrounding triglycerides with leaving a acetyl molecule apoproteins to make them more transportable in water Transamination: Adding an animo group to • Very low-density lipoproteins (VLDL ’ s) pyruvic acid to produce any of the • Low-density lipoproteins (LDL ’ s) nonessential amino acids • High-density lipoprteins (HDL ’ s) Protein Synthesis: Production of protein Lipolysis: break down lipids molecule using an RNA model. Beta Oxidation: breaking a fatty acid into 2 carbon compounds Protein catabolism: breaking down a protein Lipogenesis: formation of lipids from non-lipids into individual Amino Acids. SU SUMMARY OF TH THE INTE TERCONNECTI TION BETW TWEEN ME METABOLIC OVERVIEW: THE PO POSTABSORPTIVE ST STATE METABOLIC OVERVIEW: THE ABSORPTIVE STATE ME TISSUES TISSU S AND ME METAB ABOL OLISTIC RE REAC ACTIONS 6