2 9-1 CHEMICAL PATHWAYS CHEMICAL ENERGY and FOOD 3811 calories of heat energy are produced per gram of glucose burned.This is quite a lot of energy.1 CALORIE = amount of energy needed to raise the temperature of 1 gram of water by 1 degree C.9-1 CHEMICAL PATHWAYS CHEMICAL ENERGY and FOOD
3 Chemical Energy and Food Food labels display the number of Calories and other nutritional information about a particular product.These Calories (CAPITAL C) are actually kilocalories.Chemical Energy and Food
4 9-1 How much energy is in food? when glucose is broken down completely in the presence of oxygen, then water and carbon dioxide are producedGlycolysis is a series of enzymes catalyzes chemical reactions that change glucose one step at a time into different moleculesOne molecule of glucose is broken in half producing two molecules of pyruvic acidPyruvic Acid is a 3-C compound
5 Chemical Energy and Food Also called “sugar breaking”occurs in the cytoplasm and does not need oxygenGlycolysis only releases a small amount of energy.Let’s find out how our cells can produce the large amounts of energy we require to perform our everyday functions.Chemical Energy and Food
6 SECTION 9-1: AN OVERVIEW of Cellular Respiration When oxygen is present, the products of glycolysis enter the KREBS CYCLE and the ELECTRON TRANSPORT CHAIN.This process is called CELLULAR RESPIRATIONSECTION 9-1: AN OVERVIEW of Cellular Respiration
7 GLYCOLYSISProcess in which one molecule of glucose is broken in half producing two molecules of pyruvic acid.Pyruvic Acid is a 3-C compund.Where does the need energy in Glycolysis?To split the Glucose molecule.Cell spends 2 ATP to begin process.Makes a TOTAL of 4 ATP NET GAIN = 2 ATPWhat is the electron carrier in Glycolysis?
8 Glycolysis and NADH Production NAD+ is the electron carrier.Nicotinamide adenine dinucleotide4 HEe- are removed and passed to NAD+Each NAD+ accepts 2 HEe- NADHNAD+ helps pass energy from glucose to other cellular pathways.Energy yield is only 2 ATP but the cell can make thousands of ATP in a short time.
9 FERMENTATION Why is this a problem for the cell? NAD+ is limited and they quickly fill up with e-NAD+ is required to continue Glycolysis.FERMENTATION releases energy from food molecules in the absence of oxygen.Cells convert NADH back to NAD+Passes electrons back to Pyruvic AcidTWO TYPESAlcoholic and Lactic AcidWhat does anaerobic mean?
10 Question of the DAY NOV 12 What are the reactants of fermentation? A. ADP and NADHB. Glucose and NADHC. Pyruvic Acid and Carbon DioxideD. Pyruvic Acid and NADHQuestion of the DAY NOV 12
11 Why is NAD+ essential to a cell’s ability to produce ATP? DO NOW Nov 12
12 It transports energy from glucose to other pathways. ANSWER
13 FERMENTATION ALCOHOLIC LACTIC ACID Yeast and microorganisms Pyruvic acid +NADH yieldsEthyl Alcohol +Carbon Dioxide +NAD+Why does bread dough rise?Performed in most cellsPyruvic acid +NADH yieldsLactic Acid + NAD+Why do your muscles burn when engaging in strenuous activity?FERMENTATION
14 REVIEW OF GLYCOLYSIS What are the advantages of GLYCOLYSIS? Are there any disadvantages to GLYCOLYSIS?REVIEW OF GLYCOLYSIS
15 9-2: KREBS CYCLE and ETC DRAW Figure 9-6 in your NOTES Label all the parts and write down the STEPSANSWER the following Questions.Write down the question and the answer.1. Where does the KREBS CYCLE take place?2. How many ATP molecules are generated in one turn of the cycle?3. How many ATP are generated per one molecule of glucose?4. Where is most of the energy in pyruvic acid transferred to in this cycle?5. What is FAD? What is its role in the cycle?9-2: KREBS CYCLE and ETC
16 The Krebs Cycle 90% of energy in pyruvic acid still unused Locked in the HE electronsDiscovered by Hans KrebsBritish Biochemist in 1937Pyruvic acid from glycolysis travels into the mitochondrionKREBS CYCLE occurs hereThe Krebs Cycle
17 The Krebs Cycle Respiration is a synonym for breathing. Oxygen is the final electron acceptor.This is why organisms need to breathe in oxygen.The Krebs Cycle
18 Pyruvic Acid is broken down into carbon dioxide in a series of energy-extracting reactions. Second stage of cellular respiration.Also called the Citric Acid Cycle.Citric Acid is the first compound fromed in this process.The Krebs Cycle
19 The Krebs Cycle: STEP A 1. PA from Glycolysis enters mitochondria 2. One C from PA becomes part of CO2Released into air3. Remaining 2 C joined with Coenzyme A4. Forms Acetyl Coenzyme A (CoA)5. Acetyl CoA joins with 4 C molecule to produce Citric AcidThe Krebs Cycle: STEP A
20 1. Citric Acid (6-C) broken down to a 4-C molecule 2 molecules of CO2 released2. Electrons transferred to e- carriers.Occurs 5 times throughout cycle.NAD+ NADH FAD FADH23. ADP molecule ATPOne turn produces 4 NADH, 1 FADH2, 1 ATPOne turn = 1 Pyruvic acidHow many turns are made for 1 molecule of glucose?The KREBS CYCLE: STEP B
21 PRODUCTS of KREBS CYCLE What are the products of the KREBS Cycle?ATP, NADH, FADH2, and Carbon DioxideHow are these products used?ATP for Cellular ActivitiesCarbon Dioxide is exhaledNADH and FADH2 carry HEe- to ETCUsed to make huge amounts of ATP
22 HOMEWORK REVIEW TEXTBOOK Page 237 and 238 Answer questions and 29-30TEXTBOOK Page 239Answer questions 1-9HOMEWORK REVIEW
23 Which of the following are electron carriers? A. NAD+B. FADC. NADHD. All of the aboveQuestion of the Day Nov 13
24 What are the products of the Krebs Cycle for 1 Molecule of glucose? DO NOW Nov 13
25 ANSWER The KREBS Cycle produces 8 NADH, 2 FADH2, and 2 ATP Per molecule of GlucoseThese products are from 2 turns of the KREBS Cycle.ANSWER
26 AGENDA NOV 13 BIG Question: How do organisms produce energy? 1. QotD and DO NOW2. Chapter 93. Electron Transport Chain4. STUDY GUIDES5. Tomorrow – Review6. TEST on FRIDAY – CHAPTER 9AGENDA NOV 13
27 ELECTRON TRANSPORT CHAIN HEe- from KREBS are carried to ETC.Delivered by NADH and FADH2STEP A: HEe- passed along the ETCSeries of Carrier ProteinsInner membrane of MitochondriaElectrons lose a small amount of energy for each “jump” it they make along ETC.ELECTRON TRANSPORT CHAIN
28 Electron Transport Chain What happens to the electrons when they reach the end of ETC?Oxygen is the final electron acceptor.Enzymes combine these LEe- with H ions and Oxygen to form water.
29 ETC: ENERGY MAKING STEPS STEP B: For every 2 HEe- that pass along ETC, their energy is used to transport H+ ions from the matrix to the inner-membrane space.How many membranes does the mitochondria have?Concentration gradient is formed.
30 ETC: ENERGY MAKING STEPS STEP C: ATP SYNTHASE allows the movement of H+ ions back across the inner membrane.This movement produces energy used to make ADP + P ATPEach pair of HEe- that “jump” along ETC produce enough energy to produce 3 ATP
31 TOTALS FOR 1 Molecule of GLUCOSE GLYCOLYSIS produces 2 NADH and 4 ATP (2 ATP SPENT)KREBS CYCLE produces (2 Turns)8 NADH, 2 FADH2, and 2 ATPETC produces32 ATPTOTALS
32 The overall process of Cellular Respiration produces available to the cell. 38 ATP – 2 ATP SPENT = 36 ATPThis is 38% of the energy available in Glucose.Where does the rest of the energy go?It is lost as heat.This is why we feel hot after strenuous activity.TOTALS
33 ENERGY and EXERCISE Short Term Energy Long Term Energy Small amounts of ATP in musclesLactic Acid Fermentation takes overEnough energy to last approximately 90 secondsLong Term EnergyCellular respiration is neededReleases energy slower than fermentationStored in the carbohydrate Glycogen15 – 20 minutes of energy (then breaks down fats and other molecules)Even the most conditioned athletes must pace themselves.ENERGY and EXERCISE