* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download lecture6-BW
Mitochondrion wikipedia , lookup
NADH:ubiquinone oxidoreductase (H+-translocating) wikipedia , lookup
Biochemical cascade wikipedia , lookup
Photosynthetic reaction centre wikipedia , lookup
Fatty acid metabolism wikipedia , lookup
Basal metabolic rate wikipedia , lookup
Electron transport chain wikipedia , lookup
Photosynthesis wikipedia , lookup
Phosphorylation wikipedia , lookup
Blood sugar level wikipedia , lookup
Light-dependent reactions wikipedia , lookup
Microbial metabolism wikipedia , lookup
Evolution of metal ions in biological systems wikipedia , lookup
Citric acid cycle wikipedia , lookup
Adenosine triphosphate wikipedia , lookup
Oxidative phosphorylation wikipedia , lookup
If you could peer into the crystal ball and see how you were going to die, would you do anything different? Lecture 6: Diabetes, sugar, and ATP Objectives Understand how sugar metabolism works Understand how to make ATP Understand where sugar comes from Understand how sugar metabolism affects you Key Terms metabolism, gradient, equilibrium, phosphorylation, ATP, ADP electron transport, glycolysis, insulin, glycogen, glucagon NEXT WEEK: Cell Division and Cancer Leading Causes of Deaths 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Heart Disease: 700,142 Cancer: 553,768 Stroke: 163,538 Lung diseases: 123,013 Accidents (unintentional injuries): 101,537 Diabetes: 71,372 Influenza/ Pneumonia: 62,034 Alzheimer's disease: 53,852 Kidney Disease: 39,480 Septicemia (infection): 32,238 (Most current data available are for U.S. in 2001) www.cdc.gov/nchs/fastats/lcod.htm I don’t have to worry about that stuff till I get old! All races, both sexes, 20–24 years 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Accidents (unintentional injuries) Assault (homicide) Intentional self-harm (suicide) Cancer Heart disease Genetic abnormalities Human immunodeficiency virus (HIV) Stroke Influenza and pneumonia Diabetes Relative to the national population of 20-24’s, are MSU students less likely to die from the top 3? It’s difficult for one to prevent bad luck, or being a victim? Two Types of Diabetes Type 1 Juvenile diabetes Autoimmune disease Beta cells in pancreas are killed by defense responses Treated with insulin injections Type 2 Adults affected Insulin sensing system impaired. Beta cells stop making insulin. Pancreas burns out Treated with diet, drugs Diabetes Mellitis Cells in muscles, liver and fat don’t use insulin properly Disease in which excess glucose accumulates in blood, then urine Signs and Symptoms Excessive urination Constant thirst and or hunger Fatigue Weight loss Blurred vision Sores that don’t heal Risk Factors Age Overweight Inactive (exercise > 3x/week) Family history: African, American Indian, Asian, Pacific Islander, Hispanic or Latino descent. Siblings or parents have diabetes Gestational diabetes Blood pressure over 140/90 HDL (good) cholesterol is low and triglicerides are high Reducing Risks Physical activity- 30 min 5 days/week Diet Modification Low fat- 25% of calories max Low alcohol Maintain Reasonable body mass No crash diets Modify dietary intake What, me worry? Myths: When I leave MSU and get a job I will have as much or more free time than I do now. (I’ll still exercise as much as I do now. I’m naturally healthy, I don’t have to worry. I don’t have any risk factors so I’m immune! Diabetes Prevention Program Program Risk Reduction Healthy diet and exercise 58% Healthy diet and exercise (old folks) 71% Prevention drug 31% Control group (no change) Participants were overweight, with high blood sugar (Pre-Diabetes, impaired tolerance) Question #1 Energy for metabolic processes only comes from Sugar A. True B. False Quick Anatomy Review MOUTH(ORAL CAVITY) IN PHARYNX ESOPHAGUS STOMACH LIVER GALLBLADDER SMALL INTESTINE PANCREAS LARGE INTESTINE (COLON) RECTUM ANUS OUT Absorption Mechanisms Food is broken down to macro molecules Macro molecules are disassembled by enzymes in the intestines Actively transported across membrane: Monosaccharides Amino acids INTESTINAL LUMEN Monosaccharides (simple sugars) carbohydrates proteins amino acids EPITHELIAL CELL Nutrients diffuse from gut cells into blood stream INTERNAL ENVIRONMENT bile salts bile salts + carbohydrates proteins EPITHELIAL CELL INTERNAL ENVIRONMENT FAT GLOBULES EMULSIFICATION DROPLETS MICELLES CHYLOMICRONS Control of Glucose Metabolism insulin Glucose is absorbed Glucose uptake Glucose to glycogen Glucose falls Krispy Kreme Donuts (12) Cells use glucose Glucose rises Glycogen to glucose glucagon Many cells, especially muscle cells, take up glucose and use it as an energy source or convert it to glycogen. INSULIN Beta cells of pancreas release insulin into blood. Liver converts glucose to glycogen, fats, proteins. Blood glucose levels decline to a set point; stimulus calling for insulin diminishes. Stimulus: Glucose is absorbed following a meal. Stimulus: Cells use or store glucose between meals. Blood glucose levels increase to a set point; stimulus calling for glucagon diminishes. Liver converts glycogen to glucose, stops synthesizing glycogen. Alpha cells of pancreas release glucagon into blood. GLUCAGON IF YOU ARE LOST CLOSE YOUR EYES TILL UNTIL AFTER THE NEXT SLIDE Click to view animation. animation Using Glucose Skeletal Muscle Structure A muscle is made up of muscle cells A muscle fiber is a single muscle cell Each fiber contains many myofibrils myofibril Don’t Write This Down Myofibril A myofibril is made up of thick and thin filaments arranged in sarcomeres sarcomere sarcomere Z band sarcomere sarcomere Z band Z band Don’t Write This Down Sarcomere A bundle of two types of microfilaments Thin Filaments Thick Filaments Don’t Write This Down Muscle Microfilaments Thin filaments Like two strands of pearls twisted together Pearls are actin Other proteins in grooves in filament Thick filaments Composed of myosin Each myosin molecule has tail and a double head Don’t Write This Down Sliding-Filament Model Sarcomere shortens because the actin filaments are pulled inward, toward the sarcomere center Don’t Write This Down Sliding-Filament Model Myosin heads attach to actin filaments Myosin heads tilt toward and pull on the actin. Key Concept: Each head requires one ATP for each pull! There a lot of myosin heads in a muscle Muscle contraction requires enormous quantities of ATP! Key Concept: Contraction Requires Energy Muscle cells require huge amounts of ATP energy to power contraction The cells have only a very small store of ATP There are three pathways muscle cells use to get ATP Question #2 Cells burn insulin to make ATP A. True B. False ATP for Contraction ADP + Pi Pathway 1 DEPHOSPHORYLATION CREATINE PHOSPHATE Relaxation Contraction creatine Pathway 2 AEROBIC RESPIRATION oxygen Pathway 3 GLYCOLYSIS ALONE glucose from bloodstream and from glycogen breakdown in cells What is ATP? DEPHOSPHORYLATION! RESPIRATION! GLYCOLYSIS! What’s ATP! AND How did we get here and where are we going ATP Is Universal Energy Source Photosynthesizers get energy from the sun Animals get energy second- or third-hand from plants or other organisms Regardless, the energy is converted to the chemical bond energy of ATP Making ATP Plants make ATP during photosynthesis Cells of all organisms make ATP by breaking down carbohydrates, fats, and protein Two Main Pathways for making ATP Anaerobic pathways FAST Don’t require oxygen Start with glycolysis in cytoplasm Completed in cytoplasm Aerobic pathways SLOW Require oxygen Start with glycolysis in cytoplasm Completed in mitochondria (Note: special membrane and gradient) Overview of Aerobic Respiration CYTOPLASM glucose ATP GLYCOLYSIS energy input to start reactions e- + H+ (2 ATP net) 2 pyruvate 2 NADH MITOCHONDRION 2 NADH 8 NADH 2 FADH2 e- e- + H+ 2 CO2 e- + H+ KREBS CYCLE e- + H+ ELECTRON TRANSPORT PHOSPHORYLATION H+ 4 CO2 2 32 ATP ATP water e- + oxygen TYPICAL ENERGY YIELD: 36 ATP Overview of Aerobic Respiration C6H1206 + 6O2 glucose oxygen 6CO2 + 6H20 carbon dioxide water Overview of Aerobic Respiration CYTOPLASM glucose ATP GLYCOLYSIS energy input to start reactions e- + H+ (2 ATP net) 2 pyruvate 2 NADH MITOCHONDRION 2 NADH 8 NADH 2 FADH2 e- e- + H+ 2 CO2 e- + H+ KREBS CYCLE e- + H+ ELECTRON TRANSPORT PHOSPHORYLATION H+ 4 CO2 2 32 ATP ATP water e- + oxygen TYPICAL ENERGY YIELD: 36 ATP What’s the deal with Oxygen? (electron transport chain over simplified) Difficult to explain without using lots of really cool chemistry Key concept: If you pull water apart, it really wants to get back together again By giving the Oxygen atom in water an electron, it will give you a proton, which is actually a H+ Oxygen is the final electron acceptor? How it Works: 1. Pull a hydrogen off a water (HOH to OH-) 2. Pull the hydrogen (H+) across a membrane (electrochemical GRADIENT) 3. Make the H+ do work on its way back to OH- http://www.sp.uconn.edu/~terry/images/anim/ETS.html Question #3 More ATP is produced by the electron transport system than is produced by glycolysis A True B False Coenzyme Production Glycolysis Preparatory reactions Krebs cycle . . Total 2 NADH 2 NADH 2 FADH2 6 NADH 2 FADH 10 NADH Key Concepts: Coenzyme production 1. Kreb’s cycle produces activated coenzymes 2. Coenzymes push electron transport Making ATP: Chemiosmotic Model ATP INNER COMPARTMENT ADP + Pi ATP Synthase in Action Key Points In Summary Glucose eventually gets broken down to carbon dioxide gas Two ways to make ATP Fast way - Anerobic No oxygen required Glucose isn’t converted to CO2 but lactic acid Only net 2 ATPs/glucose Slow way - Aerobic Requires oxygen Glucose converted to CO2 Net 36 ATPs/glucose Efficiency of Aerobic Respiration 686 kcal of energy are released 7.5 kcal are conserved in each ATP When 36 ATP form, 270 kcal (36 X 7.5) are captured in ATP Efficiency is 270 / 686 X 100 = 39 percent Key Concept: Most energy is lost as heat Anaerobic Pathways Do not use oxygen Produce less ATP than aerobic pathways Two types Fermentation pathways The burn The Buzz Anaerobic electron transport Fermentation Pathways Begin with glycolysis Do not break glucose down completely to carbon dioxide and water Yield only the 2 ATP from glycolysis Steps that follow glycolysis serve only to regenerate NAD+ Lactate Fermentation GLYCOLYSIS C6H12O6 2 ATP energy input 2 NAD+ 2 ADP 2 4 NADH ATP energy output 2 pyruvate 2 ATP net LACTATE FORMATION electrons, hydrogen from NADH 2 lactate Yeasts Single-celled fungi Carry out alcoholic fermentation Saccharomyces cerevisiae Baker’s yeast Carbon dioxide makes bread dough rise Saccharomyces ellipsoideus Used to make beer and wine MSU hard cider project: Sacchromyces banyan DV10 Alcoholic Fermentation GLYCOLYSIS C6H12O6 2 ATP energy input 2 NAD+ 2 ADP 2 4 NADH ATP 2 pyruvate energy output 2 ATP net ETHANOL FORMATION 2 H2O 2 CO2 Animals Can’t do this! 2 acetaldehyde electrons, hydrogen from NADH 2 ethanol Anaerobic Electron Transport Carried out by certain bacteria Electron transport system is in bacterial plasma membrane Final electron acceptor is compound from environment (such as nitrate), NOT oxygen Doesn’t Can’t require Oxygen work with Oxygen ATP yield is low Lets bacteria live where other organisms can’t Question #4 Is Insulin a: A. Carbohydrate B. Protein C. Lipid D. Organophosphate Energy Reserves Glycogen is about 1 % of the body’s energy reserve Proteins is 21% of energy reserve Fat makes up the bulk of reserves (78 %) Note: In lecture 4 we discussed polysaccharides, proteins and lipids. Energy from Macromolecules Carbohydrate Glycogen Protein Lipids (fat) bile salts bile salts + carbohydrates proteins EPITHELIAL CELL INTERNAL ENVIRONMENT FAT GLOBULES EMULSIFICATION DROPLETS MICELLES CHYLOMICRONS Carbohydrate Breakdown and Storage Glucose is absorbed into blood Pancreas releases insulin Insulin stimulates glucose uptake by cells Cells convert glucose to glucose-6-phosphate Phosphate, functional group, phosphorylation This traps glucose in cytoplasm where it can be used for glycolysis Making Glycogen If glucose intake is high, ATP-making machinery goes into high gear When ATP levels rise high enough, glucose-6phosphate is diverted into glycogen synthesis (mainly in liver and muscle) Glycogen is the main storage polysaccharide in animals Using Glycogen When blood levels of glucose decline, pancreas releases glucagon Glucagon stimulates liver cells to convert glycogen back to glucose and to release it to the blood (Muscle cells do not release their stored glycogen. This is their stored sugar!) Key Concepts Glucose Storage 1. 2. 3. Glucose is used to make ATP first When ATP store is full, glucose is stored Glycogen is a big branched polymer of stored glucose Glycogen isn’t very soluble so it is trapped inside the cell where it is stored. Energy from Proteins Proteins are broken down to amino acids and the amino acids are broken down Amino group is removed, ammonia forms, is converted to urea and excreted Carbon backbones can enter the Krebs cycle or its preparatory reactions Key Concept: Proteins can be used to make ATP in Krebs Cycle Energy from Fats (lipids) Most stored fats are triglycerides Triglycerides are broken down to glycerol and fatty acids Fatty acids are broken down and converted to two carbon blocks that enter the Krebs cycle (acetyl CoA) Key Concept: Fatty acids are used to make ATP . Conversion is slow, 2C’s at a time Before it can even enter Krebs Cycle Processes Are Linked Aerobic Respiration Reactants Photosynthesis Reactants Sugar Carbon dioxide Oxygen Water Products Products Carbon dioxide Sugar Water Oxygen Machinery of Noncyclic Electron Flow H2O photolysis e– e– NADP+ PHOTOSYSTEM II PHOTOSYSTEM I ATP SYNTHASE NADPH ADP + Pi ATP ATP Formation in Plants When water is split during photolysis, hydrogen ions are released into thylakoid compartment. (Electrochemical GRADIENT) More hydrogen ions are pumped into the thylakoid compartment when the electron transport system operates ATP Formation Electrical and H+ concentration gradient exists between thylakoid compartment and stroma H+ flows down gradients into stroma through ATP synthesis Flow of ions drives formation of ATP Two Important Pathways Light Reaction Makes ATP from light energy Dark Reaction Makes glucose by burning ATP Uses CO2 from the air and water to make glucose Summary of Photosynthesis light 12H2O LIGHT-DEPENDENT REACTIONS 2 ADP + ATP Pi 6CO2 6O NADP+ NADPH PGA CALVIN- PGAL BENSON CYCLE RuBP P C6H12O 6 (phosphorylated glucose) end product (e.g. sucrose, starch, cellulose) Question #5 Carbon Dioxide Gas is used to build energy storage molecules in the liver A True B False Please hand your quiz sheet to Andrea or Leah on your way out Note: They will only accept one answer form from each person If you are interested in the first extra credit project, please come to the front of the class room