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Quiz Ch 6 1.What molecule does the human body use for energy for all it’s activities? Answers for question 2 and 3 include: carbon dioxide, oxygen, water,

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Presentation on theme: "Quiz Ch 6 1.What molecule does the human body use for energy for all it’s activities? Answers for question 2 and 3 include: carbon dioxide, oxygen, water,"— Presentation transcript:

1 Quiz Ch 6 1.What molecule does the human body use for energy for all it’s activities? Answers for question 2 and 3 include: carbon dioxide, oxygen, water, glucose, ATP 2. Name one of the molecules (reactants)that the body uses in respiration to make energy. 3. Name one of the products of respiration. 4. What organelle is important for cellular respiration? 5. T/F Redox reactions involve movement of electrons.

2 Space Plants

3 © 2009 Pearson Education, Inc. Space Plants Why are NASA scientists researching plants as a life- support system for long-term space flight? Why are we talking about plants and how they make oxygen?

4 © 2009 Pearson Education, Inc. Sunlight energy ECOSYSTEM Photosynthesis in chloroplasts Glucose Cellular respiration in mitochondria H2OH2O CO 2 O2O2  (for cellular work) ATP Heat energy Together, these two processes are responsible for most of the energy needs of life on Earth Plants give off oxygen and we take in oxygen. We use this oxygen along with glucose to make ATP. ATP is one of the products of cellular respiration.

5 Energy flows into an ecosystem as sunlight and leaves as heat Photosynthesis generates O 2 and organic molecules, which are used in cellular respiration Cells use chemical energy stored in organic molecules to regenerate ATP, which powers work Main purpose of cellular respiration is to produce ATP Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

6 C 6 H 12 O 6 + 6O2O2 Glucose Oxygen 6 CO 2 Carbon dioxide + 6 H2OH2O Water + ATPs Energy  Cellular respiration is a process that releases energy from the bonds in glucose and captures the energy as ATP –Cellular respiration produces 38 ATP molecules from each glucose molecule Cellular Respiration Reaction

7 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  The energy necessary for life is contained in the arrangement of electrons in chemical bonds in organic molecules  An important question is how do cells extract this energy?  Gradually Copyright © 2009 Pearson Education, Inc.

8 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  When the carbon-hydrogen bonds of glucose are broken, electrons are transferred to oxygen –Oxygen has a strong tendency to attract electrons Copyright © 2009 Pearson Education, Inc. _ + + Remember water?

9 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  Energy can be released from glucose by simply burning it  The energy is dissipated as heat and light and is not available to living organisms Copyright © 2009 Pearson Education, Inc.

10 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  On the other hand, cellular respiration is the controlled breakdown of organic molecules –Energy is released in small amounts that can be captured by a biological system and stored in ATP Copyright © 2009 Pearson Education, Inc.

11 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  A cellular respiration equation is helpful to show the changes in hydrogen atom distribution –Glucose loses its hydrogen atoms and is ultimately converted to CO 2 –At the same time, O 2 gains hydrogen atoms and is converted to H 2 O –Loss of electrons is called oxidation –Gain of electrons is called reduction Copyright © 2009 Pearson Education, Inc. Redox

12 ATP NAD + NADH H+H+ H+H+ 2e – Electron transport chain Controlled release of energy for synthesis of ATP + O2O2 H2OH2O 1212

13 ATP NAD + NADH H+H+ H+H+ 2e – Electron transport chain Controlled release of energy for synthesis of ATP + O2O2 H2OH2O 1212 Reduced or oxidized? Redox reactions involve the transfer of electrons

14 The Stages of Cellular Respiration: A Preview  Cellular respiration has three stages:  Glycolysis (breaks down glucose into two molecules of pyruvate)  The citric acid cycle (completes the breakdown of glucose)  Oxidative phosphorylation/chemiosmosis (accounts for most of the ATP synthesis) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

15 Mitochondrion CO 2 NADH ATP High-energy electrons carried by NADH NADH C ITRIC A CID C YCLE G LYCOLYSIS Pyruvate Glucose and FADH 2 Substrate-level phosphorylation Substrate-level phosphorylation O XIDATIVE P HOSPHORYLATION (Electron Transport and Chemiosmosis) Oxidative phosphorylation ATP Cytoplasm Inner mitochondrial membrane animation

16 Glycolysis  What goes in...  What comes out...  Net 2 ATP produced Glucose 2 Pyruvate + 2 ATP + 2 NADH Pyruvate and NADH will continue on in respiration to be the reactants of subsequent reactions i.e. - The Citric Acid Cycle The cell is very efficient and recycles molecules again and again

17 Glucose NAD ADP NADH2 P2 2 ATP 2 + H+H+ 2 Pyruvate Glycolysis Know this figure

18 Mitochondrion CO 2 NADH ATP High-energy electrons carried by NADH NADH C ITRIC A CID C YCLE G LYCOLYSIS Pyruvate Glucose and FADH 2 Substrate-level phosphorylation Substrate-level phosphorylation O XIDATIVE P HOSPHORYLATION (Electron Transport and Chemiosmosis) Oxidative phosphorylation ATP Cytoplasm Inner mitochondrial membrane animation

19 6.8 Pyruvate is chemically groomed for the citric acid cycle  The pyruvate formed in glycolysis is transported to the mitochondria, where it is prepared for entry into the citric acid cycle Copyright © 2009 Pearson Education, Inc. Pyruvate Acetyl CoA (coenzyme A) + CO 2 Acetyl CoA enters the citric acid cycle CO 2 is released by lungs

20 Mitochondrion CO 2 NADH ATP High-energy electrons carried by NADH NADH C ITRIC A CID C YCLE G LYCOLYSIS Pyruvate Glucose and FADH 2 Substrate-level phosphorylation Substrate-level phosphorylation O XIDATIVE P HOSPHORYLATION (Electron Transport and Chemiosmosis) Oxidative phosphorylation ATP Cytoplasm Inner mitochondrial membrane animation

21 C ITRIC A CID C YCLE NAD + NADH 3 H + CO 2  CoA Acetyl CoA P ADP + ATP FADH 2 FAD

22 Citric Acid Cycle  What goes in...  What comes out...  Net 2 ATP produced (1 per each Acetyl CoA molecule) 1Acetyl CoA + 1Oxaloacetate 1Oxaloacetate + 1ATP + 3NADH + 1 FADH + 2CO 2 Oxaloacetate is the reactant for the next cycle of the citric acid cycle NADH and FADH will continue on in respiration to be reactants of the next reaction i.e. – Oxidative Phosphorylation

23 Mitochondrion CO 2 NADH ATP High-energy electrons carried by NADH NADH C ITRIC A CID C YCLE G LYCOLYSIS Pyruvate Glucose and FADH 2 Substrate-level phosphorylation Substrate-level phosphorylation O XIDATIVE P HOSPHORYLATION (Electron Transport and Chemiosmosis) Oxidative phosphorylation ATP Cytoplasm Inner mitochondrial membrane animation

24 So far, from 1 molecule of glucose, We have produced  10 NADH (2 from glycolysis, 2 from pyruvate processing, 6 from citric acid cycle)  2 FADH  4 ATP  NADH and FADH are our electron carriers that we have been building up in order to enter oxidative phosphorylation phase  They will now enter that process and fulfill their purpose: ▫They have been carrying high energy electrons. They will now donate these electrons to produce ATP

25 Mitochondrion CO 2 NADH ATP High-energy electrons carried by NADH NADH C ITRIC A CID C YCLE G LYCOLYSIS Pyruvate Glucose and FADH 2 Substrate-level phosphorylation Substrate-level phosphorylation O XIDATIVE P HOSPHORYLATION (Electron Transport and Chemiosmosis) Oxidative phosphorylation ATP Cytoplasm Inner mitochondrial membrane animation

26 Electrons: Stair Stepping Down in Energy  As each electron is passed from protein complex to protein complex it loses energy  The energy is used to pump H + ions across the membrane to form a gradient  Each electron steps down an “energy stair” with each passage  Until it reaches its final destination and it accepted by oxygen  Oxygen will simultaneously accept the electrons and the H + ions to form water

27 ATP NAD + NADH H+H+ H+H+ 2e – Electron transport chain Controlled release of energy for synthesis of ATP + O2O2 H2OH2O 1212

28 During oxidative phosphorylation, chemiosmosis couples electron transport to ATP synthesis Following glycolysis and the citric acid cycle, NADH and FADH 2 account for most of the energy extracted from food These two electron carriers donate electrons to the electron transport chain, which powers ATP synthesis via oxidative phosphorylation Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

29 ATP NAD + NADH H+H+ H+H+ 2e – Electron transport chain Controlled release of energy for synthesis of ATP + O2O2 H2OH2O 1212 Know this figure

30 The Pathway of Electron Transport The electron transport chain is in the cristae of the mitochondrion The carriers accept and donate electrons Electrons are finally passed to O 2, forming H 2 O Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

31 Electrons are transferred from NADH or FADH 2 to the electron transport chain The electron transport chain generates no ATP The chain’s function is to break the release of energy into smaller steps that release energy in manageable amounts Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

32 Chemiosmosis: The Energy-Coupling Mechanism Electron transfer in the electron transport chain causes proteins to pump H + from the mitochondrial matrix to the intermembrane space H + then moves back across the membrane, passing through channels in ATP synthase ATP synthase uses the exergonic flow of H + to drive phosphorylation of ATP This is an example of chemiosmosis, the use of energy in a H + gradient to drive cellular work Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

33 Fig INTERMEMBRANE SPACE Rotor H+H+ Stator Internal rod Cata- lytic knob ADP + P ATP i MITOCHONDRIAL MATRIX

34 ATP H+H+ Intermembrane space O2O2 H2OH2O 1212 Inner mitochondrial membrane H+H+ NAD + H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ Mitochondrial matrix Electron flow Electron carrier Protein complex of electron carriers NADH FADH 2 FAD ATP synthase P ADP + Chemiosmosis + 2 O XIDATIVE P HOSPHORYLATION Electron Transport Chain Electrons in NADH and FADH contain potential energy. ▫This energy is used to pump H + ions across the membrane. The H + gradient contains potential energy. ▫ This energy is used to activate ATP synthase. ATP synthase converts this energy and stores it in the form of ATP. ATP synthase Electrons in NADH and FADH contain potential energy. ▫This energy is used to pump H + ions across the membrane. The H + gradient contains potential energy. ▫ This energy is used to activate ATP synthase. ATP synthase converts this energy and stores it in the form of ATP. ATP synthase Potential energy from electrons is used to synthesize ATP

35 ATP H+H+ Intermembrane space O2O2 H2OH2O 1212 Inner mitochondrial membrane H+H+ NAD + H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ Mitochondrial matrix Electron flow Electron carrier Protein complex of electron carriers NADH FADH 2 FAD ATP synthase P ADP + Chemiosmosis + 2 O XIDATIVE P HOSPHORYLATION Electron Transport Chain Electrons in NADH and FADH contain potential energy. ▫This energy is used to pump H + ions across the membrane. The H + gradient contains potential energy. ▫ This energy is used to activate ATP synthase. ATP synthase converts this energy and stores it in the form of ATP. ATP synthase Electrons in NADH and FADH contain potential energy. ▫This energy is used to pump H + ions across the membrane. The H + gradient contains potential energy. ▫ This energy is used to activate ATP synthase. ATP synthase converts this energy and stores it in the form of ATP. ATP synthase Potential energy from electrons is used to synthesize ATP

36 Many poisons and antibiotics affect the electron transport chain. What would happen to a human or a bacteria if you stopped ATP synthase? One of the electron transporters?

37 Reviewing the big picture  Know the overall equation for cellular respiration  Where do each of these reactants get consumed?  Where are the products produced?  38 ATP from each glucose molecule in aerobic respiration C 6 H 12 O 6 + 6O2O2 Glucose Oxygen 6 CO 2 Carbon dioxide + 6 H2OH2O Water + ATPs Energy

38 How many calories are released when 1 gram of glucose is completely broken down in the presence of oxygen? Each gram of sugar can provide 1.2 X ATP or 4 calories Each gram of fat can provide 2.7 X ATP or 9 calories So... it is much harder to burn off a pound of fat because it can contain so many calories. It produces more than two times the amount of ATP.

39 How many calories do you have to burn to lose a pound?  It is commonly said that a gram of fat contains 9 calories. But there are 454 grams in a pound, and 9 x 454 = 4086 calories, not  The reason for the discrepancy is that body fat, or adipose tissue, contains not only fat, but also other substances including protein, connective tissue, and water. The dietary fat referred to in the nutritional analysis of food is pure.

40 Counting Calories

41 Low carb diets  Low carb diets are based on the theory that restricting the amount of carbohydrates you eat will cause your body to burn fat to obtain the energy it needs.  When we eat, our bodies convert digestible carbohydrates into blood sugar (glucose), our main source of energy, which is stored in our liver as glycogen. When we greatly restrict our intake of carbohydrates, to the point where our liver's store of glycogen is depleted and our bodies do not find the usual source of energy readily available, they turn to our fat stores.

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43 Low carb diets  Through a process called ketosis, our body fat is "burned" or turned into fuel to provide the energy we need. Our bodies run on ketones instead of blood sugar.  Ketosis is related to halitosis (acetone)  Do low carb diets work in the long run?  Huge amounts of fat and protein  Increased cholesterol, kidney stones, decreased bone density  In the first week or two of a low-carbohydrate diet a great deal of the weight loss comes from eliminating water  Body can still use proteins and fats that you are eating for energy

44 At Atkins, we believe in science - the science it took to develop our program, the science that backs it up and the scientific approach we use to continually improve everything we do.  Our NEW and evolved diet is not the often perceived "all you can eat -- bacon, egg, and cheese diet” or the "NO CARBS DIET" as some would have you believe; but instead; Atkins is a diet rooted in the science of eating fewer refined carbohydrates and refined sugars – what we refer to as “bad carbs.”  As you will discover, the new Atkins Diet is an optimally balanced lifetime eating plan with the flexibility to meet each individual’s unique physical condition addressing factors such as age, gender, level of physical activity, and metabolic rate. The lifetime eating plan incorporates "ALL" food groups while focusing on eating some of the best foods on earth.

45 Dr Atkins dies in 2003 He is credited with revolutionizing the diet world with his theory that you can lose weight by eating fat, and his followers hailed him as a pioneer. His critics accused him of selling a dangerous idea, but Atkins dismissed their claims. Atkins' diet books were some of the best-selling books of all time. "See, that's a big mistake... to tell people to restrict calories," Atkins told CNN in January. "They lose the weight, they feel fine, then they get to their goal weight and they still have 60 more years to live, and are they going to go hungry for all 60 years?" Atkins was a cardiologist and businessman, selling supplements and food on his Web site and at the Atkins Center for Complementary Medicine. All of his best-selling diet books promoted the same philosophy: a diet high in fat and protein and low in carbohydrates is a sure way to lose weight. "It's not that it needs to be low-calorie. As long as you cut out the carbohydrate the weight loss is automatic," Atkins said.

46 Food, such as peanuts ProteinsFatsCarbohydrates Glucose O XIDATIVE P HOSPHORYLATION (Electron Transport and Chemiosmosis) CITRIC ACID CYCLE Acetyl CoA GLYCOLYSIS Pyruvate Amino acids Glycerol Sugars Fatty acids Amino groups G3P ATP

47 Is fermentation your friend?

48 6.13 Fermentation enables cells to produce ATP without oxygen  Fermentation occurs if there is not enough oxygen to undergo cellular respiration  It is Plan B for our cells and used as a last resort because it is less efficient at producing ATP  Fermentation is an anaerobic (without oxygen) energy-generating process –It takes advantage of glycolysis, producing two ATP molecules and reducing NAD + to NADH –The trick is to oxidize the NADH without passing its electrons through the electron transport chain to oxygen Copyright © 2009 Pearson Education, Inc.

49 6.13 Fermentation enables cells to produce ATP without oxygen  Your muscle cells and certain bacteria can oxidize NADH through lactic acid fermentation –NADH is oxidized to NAD + when pyruvate is reduced to lactate –In a sense, pyruvate is serving as an “electron sink,” a place to dispose of the electrons generated by oxidation reactions in glycolysis Copyright © 2009 Pearson Education, Inc.

50 Glucose NADH NAD NADH 2 NAD ADP P ATP 2 2 Pyruvate 2 Lactate GLYCOLYSIS Lactic acid fermentation  2 During intense exercise, this lactic is produced faster than is can be removed from the muscles, used to be thought this is what made you sore the next day

51 Lactic Acid Fermentation  What goes in...  What comes out...  Net 2 ATP produced  How many ATP are produced with respiration? 1 glucose+ 2 NAD + 2 Lactate + 2ATP + 2NADH Compare this to respiration in which 38 ATP are produced for each molecule of glucose

52 Are you a better sprinter or distance runner?  It is generally accepted that muscle fiber types can be broken down into two main types: slow twitch muscle fibers and fast twitch muscle fibers  Human muscles contain a genetically determined mixture of both slow and fast fiber types, usually about 50/50 but the percentage of muscle fiber type varies from person to person

53 Distance runners  The slow twitch muscles are more efficient at using oxygen to generate more ATP  This allows continuous, extended muscle contractions over a long time  They fire more slowly than fast twitch fibers and can go for a long time before they fatigue  Therefore, slow twitch fibers are great at helping athletes run marathons and bicycle for hours What type of energy making process are slow twitch muscles using? Nick Harrison wins the Melbourne Marathon theage.com

54 Sprinters/body builders  Fast twitch fibers use anaerobic metabolism to create fuel  Much better at generating short bursts of strength or speed than slow muscles.  They fatigue more quickly. Fast twitch fibers generally produce the same amount of force per contraction as slow muscles, but they get their name because they are able to fire more rapidly.  They are not effective in longer-term training, but are very useful in brief, high-intensity training like we see in sprinting, bodybuilding, or powerlifting What type of energy making process are slow twitch muscles using? Fermentation or respiration?

55 Are Athletes Born or Built? Can Training Change Fiber Type?

56 Do you like the white or the dark meat?  Chickens have fast and slow twitch muscle, too  Dark meat, like in the drumstick, is mostly made up of slow twitch fibers  Chickens use their legs for walking and standing, which they do for extended periods  White meat, like in chicken wings and breasts, is mostly made up of fast twitch muscle  They use their wings for quick bursts of flight

57 White or dark meat? WikiAnswers  Are chicken wings considered dark meat?  White vs. Dark Chicken Meat  Chicken wings, like the breast, are white meat.  Chicken wings are white meat. I worked at KFC (management) for nearly 10 years. Wings are white meat!

58 6.13 Fermentation enables cells to produce ATP without oxygen  The baking and winemaking industry have used alcohol fermentation for thousands of years –Yeasts are single-celled fungi that not only can use respiration for energy but can ferment under anaerobic conditions –They convert pyruvate to CO 2 and ethanol while oxidizing NADH back to NAD + Copyright © 2009 Pearson Education, Inc.

59 Alcoholic Fermentation  What goes in...  What comes out...  Net 2 ATP produced  How many are produced with respiration? 1 glucose+ 2 NAD + 2 Ethanol + 2 CO 2 + 2ATP + 2NADH Compare this to respiration in which 38 ATP are produced for each molecule of glucose

60 2 ADP P ATP 2 GLYCOLYSIS NADH NAD NADH 2 NAD Pyruvate 2 Ethanol Alcohol fermentation Glucose CO 2 2 released  2

61 Alcoholic Beverages Made by fermentation – Beer, wine – The chemical reaction of yeast on sugars Beers –Most beers are made from barley malt –Ground up malt is added to barley to make mash –Mash is combined with the flavoring, hops, and fermentation begins –The fermentation can last for several weeks –Can use open fermentation and rely on vigorous yeast action to produce a protective CO2 blanket –The average beer is somewhere between 2-6% alcohol Harvesting hops

62 Wine Made from grapes – Crush grapes – Ferment the juices – Most wines are ferment for 4 years or more – Contain 7-24% alcohol Why do beer/wine fermentation reactions have to take place in areas without oxygen? Why does wine have a higher alcohol percentage than beer?

63 Wine Made from grapes – Crush grapes – Ferment the juices – Most wines are ferment for 4 years or more – Contain 7-24% alcohol If oxygen were present than yeast would use the far more efficient mechanism of respiration The yeasts differ. Most beer yeasts cannot tolerate high concentrations of alcohol. When a brewer wants to ferment a high-alcohol beer, he uses a champagne yeast or specially-bred yeast to finish the fermentation.

64 There will be a quiz next class. It will cover chapters 5 and 6.


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