Slide 1 / 142 Slide 2 / 142 Biology Energy Processing www.njctl.org Acetyl Co-A aerobic anabolic pathway anaerobic synthase Calvin Cycle catabolic pathway cellular respiration chlorophyll citric acid cycle cyclic energy transport electron acceptor Slide 3 / 142 Vocabulary Click on each word below to go to the definition. Energy Processing Unit Topics electron transport chain ethanol fermentation facultative anaerobe FADH2 fermentation glycolysis Krebs cycle lactic acid fermentation light dependent reactions light independent reactions metabolism NADH NADPH Slide 5 / 142 Click on the topic to go to that section noncyclic energy transport obligate aerobe obligate anaerobe oxidation oxidative phosphorylation phosphorylation photosynthesis photosystem I photosystem II pyruvate pyruvate decarboxylation reduction thylakoid Slide 4 / 142 Vocabulary Click on each word below to go to the definition. Slide 6 / 142 Chapter 8 Metabolism & Metabolism & Cellular Respiration Fermentation Photosynthesis Return to Table of Contents
Slide 7 / 142 Metabolic Pathways Slide 8 / 142 Metabolic Pathways Metabolism is the totality of an organism s chemical reactions. Metabolism is a property of all life. A metabolic pathway begins with a specific molecule and ends with a product Each step is catalyzed by a specific enzyme Without enzymes, metabolic pathways would proceed very slowly. enzyme 1 enzyme 2 enzyme 3 A B C D Reaction 1 Reaction 2 Reaction 3 Starting Molecule Product Slide 9 / 142 Metabolic Pathways Slide 10 / 142 Catabolic Pathways There are two types of metabolic pathways: Catabolic pathways Anabolic pathways Catabolic pathways break down molecules from the environment. Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell processes. Slide 11 / 142 Exergonic Reaction Catabolic pathways are exergonic reactions; the change in Gibbs free energy is negative. Thus, they release energy and occur spontaneously Slide 12 / 142 Anabolic Pathways Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways. Free energy Reactants Energy Products Amount of free energy released (ΔG<0) Examples: building bones building muscle building starch powering active transport Click here for a pneumonic device Progress of the reaction
Slide 13 / 142 Endergonic Reaction Anabolic pathways are endergonic reactions; the change in Gibbs free energy is positive. Thus, they require an input of energy and do not occur spontaneously Slide 14 / 142 Spontaneous Processes A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system. G takes into account the resulting change in the energy of a system and the change in its entropy. Free energy Reactants Energy Products Amount of free energy required (ΔG > 0) If the effect of a reaction is to reduce G, the process will proceed spontaneously. If G is negative, the reaction will occur spontaneously. If G is zero or positive, it will not occur spontaneously. Progress of the reaction Slide 15 / 142 Free Energy and Metabolism Slide 16 / 142 Adding Coupled Reactions Biological systems often need an endergonic reaction to occur, but on it's own, it won't proceed spontaneously. To be able to occur, the endergonic reaction is coupled to a reaction that is exergonic, so that together, they are exergonic. Non-spontaneous reaction: G is positive Glu Glutamic acid + NH 3 Ammonia NH 2 Glu Spontaneous Reaction: G is negative + H 2O ADP G = +3.4 kcal/mol G = -7.3 kcal/mol + P i together, reactions are spontaneous G = 3.9 kcal/mol Slide 17 / 142 1 A spontaneous reaction. A occurs only when an enzyme or other catalyst is prese B cannot occur outside of a living cell C releases free energy when proceeding in the forward direction D is common in anabolic pathways E leads to a decrease in the entropy of the universe Slide 18 / 142 2 Anabolic pathways are and catabolic pathways are. A B C D spontaneous, non-spontaneous endergonic, exergonic exergonic, endergonic endothermic, endergonic
Slide 19 / 142 3 Which of the following correctly states the relationship between anabolic and catabolic pathways? A B C Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways. Energy derived from catabolic pathways is used to drive breakdown of organic molecules in anabolic pathways. Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathw Slide 20 / 142 Cell Energy A cell does three main kinds of work: Mechanical (motion) Transport (crossing a barrier) Chemical (changing a molecule) To do work, cells manage energy resources by energy coupling, using an exergonic reaction to drive an endergonic one Slide 21 / 142 Cells can store the energy from catabolic pathways in a molecule called (adenosine triphosphate). can be broken down later to fuel anabolic reactions. Slide 22 / 142 (adenosine triphosphate) includes three phosphate groups (PO 4-3 ). Each Phosphate group has an ionic charge of -3e. In this model of, each PO 4-3 is circled in blue. Slide 23 / 142 The phosphate groups repel each other, since they each have a negative charge. Therefore it requires Work to add the second phosphate group; to go from AMP (monophosphate) to ADP (diphosphate). To add the third group, to go from ADP to (triphosphate), requires even more work since it is repelled by both of the other phosphate groups. Slide 24 / 142 This is like the work in compressing a spring. The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond. When the bond is broken to go from to ADP, significant energy is released. Going from ADP to AMP releases less energy, since there is less total charge in ADP than.
Slide 25 / 142 The bonds between the phosphate groups of s tail can be broken by hydrolysis. Energy is released from when the terminal phosphate bond is broken. The released energy is equal to the work that was done to form the bond. That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule. Slide 26 / 142 In the living systems, the energy from the exergonic reaction of hydrolysis can be used to drive an endergonic reaction. Overall, the coupled reactions are exergonic. The result is a chemical change to a state of lower free energy. Slide 27 / 142 Slide 28 / 142 Performs Work drives endergonic reactions by phosphorylation, transferring a phosphate group to some other molecule, such as a reactant. The recipient molecule is now "phosphorylated". The three types of cellular work are powered by the hydrolysis of. Performs Work P Motor protein Mechanical work: phosphorylates motor proteins Membrane protein P Solute P i Protein moved P i Solute transported ADP + P i Transport work: phosphorylates transport proteins P Glu NH2 + NH3 + Glu P i Reactants: Glutamic acid and ammonia Product (glutamine) made Chemical work: phosphorylates key reactants Slide 29 / 142 The Regeneration of is a renewable resource that is regenerated by addition of a phosphate group to ADP The energy to phosphorylate ADP comes from catabolic reactions in the cell Slide 30 / 142 The Regeneration of The chemical potential energy temporarily stored in drives most cellular work Each cell is converting millions of to ADP and back again every second. Energy from catabolism (exergonic, energy yielding processes) ADP + P i Energy for cellular work (endergonic, energy consuming processes)
Slide 31 / 142 4 In general, the hydrolysis of drives cellular work by. A releasing free energy that can be coupled to other reacti B releasing heat C acting as a catalyst D lowering the free energy of the reaction Slide 32 / 142 5 What best characterizes the role of in cellular metabolism? The release of free energy during the hydrolysis of AT A heats the surrounding environment. B C D The free energy released by hydrolysis may be c to an endergonic process via the formation of a phosphorylated intermediate. It is catabolized to carbon dioxide and water. The ΔG associated with its hydrolysis is positive. Slide 33 / 142 6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of? A B C D Mechanical work, such as the movement of the cell Transport work, such as the active transport of an ion into cell. Chemical work, such as the synthesis of new proteins. The production of heat, which raises the temperature of cell. Slide 34 / 142 Cellular Respiration Return to Table of Contents Slide 35 / 142 Equilibrium and Metabolism Reactions in a closed system eventually reach equilibrium and then stop. Life is an open system materials and energy. Life is not in equilibrium, experiencing a constant flow of Life cannot survive without connection to the environment. Slide 36 / 142 The Production of Catabolic Pathways Cellular respiration is a catabolic pathway that consumes organic molecules and yields. Carbohydrates, fats, and proteins can all fuel cellular respiration. We'll look first at the simplest case, the breakdown of the sugar - glucose. But before doing that we have to learn about two molecules that are essential to respiration.
Slide 37 / 142 NAD + and FAD The molecules NAD + and FAD are used to store, and later release, energy during respiration; they are key to respiration. Each molecule has two forms, each form stores a different amount of energy. So moving between those two forms either stores chemical potential energy or releases it. Here are the reactions: NAD + + 2H + + 2e - + Energy NADH + H + Slide 38 / 142 NAD + and FAD NAD + + 2H + + 2e - + Energy NADH + H + FAD + 2H + + 2e - + Energy FADH 2 The amount of energy that is useable when the reaction goes to the left, depends on the availability of electron acceptors. Without a molecule, such as O2, to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make. FAD + 2H + + 2e - + Energy FADH 2 The double arrows indicate that each reaction is reversible, they can proceed in either direction. When the reaction goes to the right, energy is stored. When it goes to the left, energy is released Slide 39 / 142 Electron Acceptors Oxygen is the best electron acceptor because it generates the greatest free energy change (#G) and produces the most energy. In the absence of oxygen, other molecules, such as nitrate, sulfate, and carbon dioxide can be used as electron acceptors. Slide 40 / 142 7 NADH is converted to NAD +. During this process, A energy is released B energy is stored C no energy is stored or released If O2 is present, 1 NADH stores enough energy to create about 3 s 1 FADH2 stores enough energy to make about 2 s Slide 41 / 142 8 FADH 2 is converted to FAD. During this process, A energy is stored B energy is released C no energy is stored or released Slide 42 / 142 Reduction and Oxidation NAD + + 2H + + 2e - + Energy NADH + H + FAD + 2H + + 2e - + Energy FADH 2 When we go from left to right we are adding electrons to a molecule. That is called reducing the molecule, or the process of reduction. Going from right to left, we are taking electrons from a molecule. That is called oxidizing the molecule, or the process of oxidation.
Slide 43 / 142 Oxidation Slide 44 / 142 Reduction and Oxidation The reason for the term oxidation is that this is the effect that oxygen usually has: it takes electrons from a molecule, oxidizing the molecule The rusting of iron is an example of oxidation: oxygen is taking electrons from the metal, oxidizing it. 4 Fe + 3 O 2 2 Fe 2 O 3 Since it doesn't seem right that adding electrons is called "reduction"; here's a way to remember these two terms. LEO says GER Losing Electrons is Oxidation Gaining Electrons is Reduction Slide 45 / 142 9 Which of the following cannot act as an electron acceptor? A sulfate B oxygen C ammonia D nitrate Slide 46 / 142 10 The loss of an electron is and the gain of an electron is. A oxidation, reduction B reduction, oxidation C catalysis, phosphorylation D phosphoroylation, catalysis Slide 47 / 142 11 NADH is the reduced form of NAD +. True False Slide 48 / 142 Types of Cellular Respiration Cells follow different paths of cellular respiration depending on the presence or absence of oxygen. Cells can be classified into 3 categories based on their response to oxygen. Obligate Anaerobes - which cannot survive in the presence of oxygen Obligate Aerobes - which require oxygen Facultative Anaerobes - which can survive in the presence or absence of oxygen.
Slide 49 / 142 The Stages of Respiration Cellular respiration consists of four stages: Slide 50 / 142 Glycolysis Glycolysis is the first stage of cellular respiration. It involves the breakdown of glucose, a 6 carbon sugar, into 2 molecules of pyruvate, a 3 carbon sugar. Glycolysis Pyruvate Decarboxylation The Citric Acid Cycle (Krebs Cycle) Oxidative Phosphorylation 2 NAD + 2 NADH C 6H 12O 6 (Glucose) Gycolysis 2 4 Glycolysis means the splitting of glucose Some is needed to start the process (E a) 2 C 3H 4O 3 (Pyruvate) The net result is: a net of 2 s are formed along with 2 NADHs and the 2 pryuvates. Slide 51 / 142 12 Until 2.5 billon years ago there was no oxygen in the Earth's atmosphere. Which of the following was also not present? A facultative anaerobes B obligate anaerobes C obligate aerobes D bacteria Slide 52 / 142 13 How much activation energy is required to start glycolysis? A 0 B 1 C 2 D 4 Slide 53 / 142 14 The net products of glycolysis are: A 2 pyruvate B 2 NADH and 2 pyruvate C 2, 2 NADH, and 2 pyruvate D 4, 2 NADH, and 2 pyruvate Slide 54 / 142 Pyruvate Decarboxylation (PD) The Citric Acid Cycle can only process 2-carbon molecules, and pyruvate is a 3-carbon molecule: C 3H 4O 3 2 NAD + 2 NADH 2 C 3H 4O 3 (Pyruvate) PDC 2 Acetyl Co-A 2 CO2 PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl Co- A molecules: these are 2-carbon molecules. Energy is stored during PD by the converting 2 NAD + to 2 NADH and the extra pyruvate carbons are expelled as CO 2.
Slide 55 / 142 The Citric Acid Cycle Slide 57 / 142 The Citric Acid Cycle This shows one cycle, which is due to one Acetyl Co-A molecule. To account for one glucose molecule, two cycles are needed. Let's tally up the output for one cycle to confirm our results. The citric acid cycle is sometimes called the Krebs cycle. The cycle breaks down one Acetyl-CoA for each turn, generating 1, 3 NADH, 2 CO 2 and 1 FADH 2 per Acetyl-CoA. Since 2 Acetyl-CoA molecules were created from each glucose, the Citric Acid Cycle creates 2 ; 6 NADH; 4CO 2, and 2 FADH 2 for each glucose molecule. Slide 56 / 142 The Citric Acid Cycle Click here for a video of the Citric Acid Cycle Slide 58 / 142 15 Glycolysis produces. This is one turn of the cycle, due to 1 Acetyl Co- A. Note the production of: 1 3 NADH 1 FADH 2 But 1 glucose molecule, yields 2 Acetyl Co-A molecules, (therefore, 2 turns of the cycle) yielding : 2 6 NADH 2 FADH 2 Pyruvate Decarboxylation produces. The Citric Acid Cycle produces. A 1, 1, 2 B 4, 0, 2 C 4, 0, 4 D 2, 0, 2 Slide 59 / 142 16 During pyruvate decarboxylation, 3-carbon pyruvate is converted to 2-carbon Acetyl-CoA. What happens to the excess carbons atoms in this process? A They are expelled in molecules of CH 4 B They are expelled in molecules of CO 2 C They are covalently bonded to NADH D They are recycled to reform glucose Slide 60 / 142 17 In total, the first 3 stages of cellular respiration produce how many molecules of carbon dioxide? A 1 B 2 C 3 D 6
Slide 61 / 142 Oxidative Phosphorylation (OP) So far we've done a lot of work to just get a net gain of 4 s. But we have stored a lot of potential energy in the form of NADH and FADH 2. The big energy payoff is in oxidative phosphorylation, where we convert the energy stored in those molecules to. Slide 62 / 142 Oxidative Phosphorylation (OP) We're now going to convert all the NADH and FADH 2 into, so the energy can be stored throughout the cell. Here's what we start this cycle with. Stage NADH FADH2 Glycolysis 2 0 2 PD 2 0 0 CAC 6 2 2 Total 10 2 4 When O 2 is present, we get about 3 s per NADH and 2 s per FADH 2. So how many s would we have at the end of this next stage? Slide 63 / 142 Electron Transport Chain (ETC) Oxidative phosphorylation is powered by thelectron transport chain. One way to think of the ETC is as a proton pump. The ETC transports electrons, through chemical reactions, out and then back through a plasma membrane. The net effect is to pump protons from the inside to the outside of a plasma membrane, creating a proton gradient which is used to power oxidative phosphorylation. Slide 64 / 142 Electron Transport Chain (ETC) The proton path in red. The electron path is shown in black. The ETC generates no, but enables Oxidative Phosphorylation, which accounts for most of the produced. Slide 65 / 142 Anaerobic ETC For the first 2 billion years of life on Earth, anaerobic (no O 2) respiration was the only means of obtaining energy from food. 2- These organisms used the electron acceptors, NO 3-, SO 4, or CO 2 to pull the electrons through the ETC. These molecules would accept the electrons at the end of the chain forming 2, N H 2S, and CH 4 respectively. Slide 66 / 142 Aerobic ETC But then, the Oxygen Revolution occurred about 2.5 BYA, flooding the planet with oxygen. In aerobic respiration, the final electron acceptor of the electron transport chain is O 2; forming water (H 2O). Oxygen strongly attracts electrons in order to fill its outer shell. This stronger pull makes much more energy available to life, enabling the more complex food chains we see today. Click here for a video of the ETC
Slide 67 / 142 18 Which of the following is created during the electron transport chain in human cells? Slide 68 / 142 19 Obligate aerobes use which of the following as their final electron acceptor? I II NADH III proton gradient A B C D I, II, III, IV I, II only III only III, IV only A CO 2 B NO 3 - C O 2 D SO 4 2- IV H 2O Slide 69 / 142 Oxidative Phosphorylation (OP) The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside. The excess protons outside, are strongly attracted to the inside, but are blocked by the membrane. One path is open to the protons, but they must do work to use it. Synthase is essentially a motor, constructed of proteins. The protons must travel through that motor in order to return to the cell, creating an electric current that powers the motor. As the motor turns, it adds a phosphate group to ADP, creating. Electrical energy is transformed to chemical energy. Slide 70 / 142 Oxidative Phosphorylation The Hydroelectric Analogy The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water Click here for a video of Synthase Slide 71 / 142 Oxidative Phosphorylation The Hydroelectric Analogy Slide 72 / 142 Oxidative Phosphorylation The Hydroelectric Analogy Like oxidative phosphorylation, it creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline, transforming it to kinetic energy. Massive turbines are spun, causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy.
Slide 73 / 142 Aerobic Respiration We calculated earlier that we would expect to get 38 molecules by the time we'd converted all the NADH and FADH 2 to. The actual yield is between 36-38 molecules per glucose molecule. 20 synthase... A synthesizes B is an enzyme C is a protein complex D all of the above Slide 74 / 142 The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC. Slide 75 / 142 21 Energy released by the electron transport chain is used to pump H+ ions into which location? A Outside the membrane B Inside the membrane Slide 76 / 142 22 What is the maximum number of produced from a breakdown of a glucose molecule? A 4 B 18 C 36 D 38 Slide 77 / 142 The Versatility of Catabolism Slide 78 / 142 The Versatility of Catabolism Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration. Glycolysis accepts a wide range of carbohydrates Proteins must be digested to amino acids; amino groups can feed glycolysis or the citric acid cycle Fats are digested to glycerol which is used in glycolysis. An oxidized gram of fat produces more than twice as much as an oxidized gram of carbohydrate
Fermentation Slide 79 / 142 Slide 80 / 142 Fermentation When no electron acceptors are available, obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation. Fermentation begins just as cellular respiration does, with glycolysis. Return to Table of Contents Slide 81 / 142 Fermentation Slide 82 / 142 Fermentation Glycolysis results in 2 pyruvate molecules and 2 NADH2 molecules. Without an electron acceptor, the energy stored in these molecules can't be used. The net energy gain is just 2 s. (Remember 2 were invested and 4 were produced, netting 2) 2 NAD + 2 NADH C 6H 12O 6 (Glucose) Gycolysis 2 C 3H 4O 3 (Pyruvate) 2 4 However, the Pyruvate still needs to be cleared from the cell, and the NADH converted back to NAD + to begin another cycle. The process of doing this is called fermentation. No additional energy is released during this process. 2 NAD + 2 NADH C 6H 12O 6 (Glucose) Gycolysis 2 C 3H 4O 3 (Pyruvate) 2 4 There are two types of fermentation: Lactic acid fermentation Ethanol fermentation Slide 83 / 142 Types of Fermentation 2 NADH 2 C 3H 4O 3 (Pyruvate) Fermentation 2 NAD + OR Lactic Acid Fermentation 2 Lactic Acid Ethanol Fermentation 1 glucose molecule had yielded 2 s, 2 Pyruvates and 2 NADHs. That is the input to the fermentation stage of anaerobic respiration. The pyruvates and NADHs are fermented into 2 NAD and + either Lactic Acid or CO2 & Ethanol. Slide 84 / 142 Fermentation Fermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule. 2 NADH 2 NAD + Lactic Acid Fermentation 2 C3H4O3 (Pyruvate) 2 Lactic Acid Fermentation OR Ethanol Fermentation CO 2 & 2 Ethanol CO2 & 2 Ethanol
Slide 85 / 142 Fermentation The result of the combined steps of glycolysis and fermentation is: The input is 1 Glucose + 2 molecules The output is 4 molecules (for a net gain of 2 's) In addition, Slide 86 / 142 Cellular Respiration vs. Fermentation The big difference is that for each glucose molecule: aerobic cellular respiration yields 36 to 38 s fermentation yields only 2 s Lactic Acid fermentation results in lactic acid Ethanol fermentation results in ethanol and CO2 Slide 87 / 142 Examples of Fermentation Slide 88 / 142 23 When a cell has completed glycolysis and lactic acid fermentation, the final products are: Some anaerobic bacteria rely soley on fermentation, such as lactobacillus, which is used to make cheese and yogurt. I Lactic acid The alcohol in wine, beer, etc. results from yeast (a facultative anaerobe) undergoing ethanol fermentation. Bread rises due to the release of CO 2 bubbles by fermenting yeast. Your muscles burn after a strenuous workout because they can't get enough O 2, so they perform lactic acid fermentation. Lactic acid results in soreness. II Ethanol III Carbon dioxide IV NADH V A B C D I, II, III, IV, V I, II, III, V I, IV, V I, V Slide 89 / 142 24 Bread rises due to the production of during fermentation. A ethanol B carbon dioxide C lactic acid D pyruvate Slide 90 / 142 25 Muscles produce lactic acid during strenuous exercise. Therefore, muscles are an example of what kind of cell? A facultative anaerobe B facultative aerobe C obligate anaerobe D obligate aerobe
Slide 91 / 142 Photosynthesis Slide 92 / 142 Photosynthesis Respiration gets energy from glucose and stores it as. But what is the source of glucose? And, where did the oxygen that flooded Earth 2.5 BYA come from? Return to Table of Contents Slide 93 / 142 Aerobic Respiration vs. Photosynthesis Slide 94 / 142 Aerobic Respiration vs. Photosynthesis Here's the balanced chemical equation for aerobic respiration: C 6H 12O 6 + 6O 2 6CO 2 + 6H 2O + C 6H 12O 6 + 6O 2 6CO 2 + 6H 2O + And here's the balanced chemical equation for photosynthesis: 6CO 2 + 6H 2O + Light Energy C 6H 12O 6 + 6O 2 Aerobic respiration uses oxygen (O2) and glucose (C6H12 O6) to create carbon dioxide (CO2) and water (H2O)...and release energy. 6CO 2 + 6H 2O + Light Energy C 6H 12O 6 + 6O 2 Photosynthesis is the exact opposite, it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12 O6) and oxygen (O2) Slide 95 / 142 Photosynthesis and Respiration Slide 96 / 142 Photosynthesis and Respiration Summing these two equations reveals that the used by cells is derived from light energy, from the sun. That is the source of energy for most life on Earth. Light Energy (Energy) C 6H 12O 6 + 6O 2 6CO 2 + 6H 2O + (Energy) 6CO 2 + 6H 2O + Light Energy C 6H 12O 6 + 6O 2 Except for a small number of bacteria that live on chemical reactions in challenging environments, the energy for all life on Earth comes from thes processes...from the energy of sunlight. Even though not every organism undergoes photosythesis, the products that plants produce are used in reactions that consumers use. In this way, you can say that... Light Energy (Energy) You are solar powered!
Slide 97 / 142 26What are the reactants of cellular respiration? Slide 98 / 142 27 What are the products of photosynthesis? A Oxygen and Water A Glucose and Oxygen B Glucose and Carbon Dioxide B Oxygen and Water C Glucose and Water C Glucose and Carbon Dioxide D Glucose and Oxygen D Carbon Dioxide and Water Slide 99 / 142 Slide 100 / 142 28 What are the reactants of photosynthesis? A Carbon Dioxide and Water B Oxygen and Water C Glucose and Oxygen D Glucose and Carbon Dioxide 29 Photosynthesis energy, whereas cellular respiration energy. A B C D consumes, produces produces, consumes produces, produces consumes, consumes Slide 101 / 142 Our Original Questions Slide 102 / 142 Photosynthesis What is the source of glucose? Where did the oxygen that flooded Earth 2.5 BYA come from? The products of photosynthesis are: oxygen (O2) glucose (C 6H12O6) Photosynthesis produces the glucose that feeds respiration, and eventually, all of us. Photosynthesis also produces the oxygen that filled the atmosphere and made complex life, as we know it possible.
Slide 103 / 142 The Oxygen Catastrophe Photosynthesis and the addition of oxygen to Earth's atmosphere, began about 2.5 BYA, and was having a major impact by 2.0 BYA. This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes. Some survive today, but only in locations where they are not exposed to the atmosphere. Slide 104 / 142 Photosynthesis 6CO 2 + 6H 2O + Light Energy C 6H 12O 6 + 6O 2 This simple equation sums up the result of photosynthesis: its reactants and products. However, the processes that make photosynthesis possible are not very simple. Just like the four stages of respiration result in a simple equation, the process itself is complicated. Similarly, the process of photosynthesis is complicated. And in some ways similar to the steps of respiration, but backwards. Slide 105 / 142 30 In the comparison of aerobic respiration to photosynthesis, which statement is true? Slide 106 / 142 NADPH A B C D oxygen is a waste product in photosynthesis but not in respiration glucose is produced in respiration but not in photosynthesis carbon dioxide is formed in photosynthesis but not in respiration water is formed in photosynthesis but not in respiration During respiration the molecules NAD + and FAD are used to store energy. Photosynthesis uses the molecule NADP +, which is a lot like NAD +, to store energy, and convert it between its two stages. The reduced form of NADP + is NADPH. Slide 107 / 142 Chlorophyll Slide 108 / 142 Thylakoids Photosynthesis also depends on chlorophyll, a molecule that absorbs red and violet-blue light and uses it to energize electrons to a higher energy level. Chlorophyll is housed in thylakoids, membrane-bound structures within photosynthetic cells. Chlorophyll gives plants their green color.
Slide 109 / 142 31 NAD + is to NADP + as NADH is to. A NADP 2+ B NADP C NADPH D NADPH 2 Slide 110 / 142 32 Which of the following is found stored in the thylakoid? A B chlorophyll C NADH D NADPH Slide 111 / 142 Two Types of Photosynthesis Slide 112 / 142 Cyclic Energy Transport There are two types of photosynthesis: Cyclic Energy Transport Non-CyclicEnergyTransport Cyclic Energy Transport was probably the first type of photosynthesis to originate. It does not create glucose, it just converts solar energy to. Slide 113 / 142 Cyclic Energy Transport Cyclic Energy Transport uses Photosystem I, a protein complex embedded in the thylakoid membrane to convert light energy to. Photosystem I Electron Transport Chain Slide 114 / 142 33 Noncyclic energy transport arose before cyclic energy transport. True False Energy of molecules e - e- e - chlorophyll Synthase e - ADP + P i This process is "cyclic" because the final electrons return to chlorophyll after is generated. photon
Slide 115 / 142 34 Which of the following statements about cyclic energy transport is true? A Cyclic energy transport requires water. B Glucose is produced by cyclic energy transport. C Cyclic energy transport reduces NADP + Light energy is converted to chemical energy during D cyclic energy transport. Slide 116 / 142 Noncyclic Energy Transport There are two major stages to Noncyclic Energy Transport: Light Dependent Reactions Light Independent Reactions (Calvin Cycle) Slide 117 / 142 Light Dependent Reactions Light Dependent Reactions occur in membrane bound structures called thylakoids. It's necessary to have a membrane surface separating the inside from the outside on an enclosed volume, thylakoids provide that. The inside is called the lumen; the outside is called the stroma. Slide 118 / 142 Light Dependent Reactions The Light Dependent Reactions use light energy and water to form, NADPH, and oxygen gas. 2 H 2O + 2 NADP + + 3 ADP + 3 P i O 2 + 2NADPH + 3 This process requires 2 photosystems, Photosystem II and Photosystem I. They occur in this order (they were named in the order in which they were discovered). Slide 119 / 142 Thylakoid This shows the membrane, separating the stroma from the lumen, the two photosystems and the enzymes, Synthase and NADP Reductase. The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma, and a deficit in the lumen. The only way protons can get back to the lumen, is through Synthase, to produce. Slide 120 / 142 Photosystem II First, Photosystem II absorbs light and energizes electrons, splitting a water molecule in the process. Those are used to pump protons across the membrane, creating an electrical potential difference which is used to create. Energy of molecules H 2O O 2+2H + Photosystem II e - e - e - chlorophyll Electron Transport Chain Synthase e - ADP + P i to Photosystem I photon
Slide 121 / 142 Photosystem I Then, Photosystem I absorbs more light and re-energizes those electrons. They are used to store energy by using NADP Reductase to reduce NADP + to NADPH (adding electrons to NADP +, instead of returning them to chlorophyll as in cyclic energy transport). Energy of molecules e - from Photosystem II Photosystem I e - e - e - chlorophyll photon Slide 123 / 142 NADP Reductase NADP+ NADPH 36 Light dependent reaction produce and NADPH for each O 2 produced. A 1, 1 B 2, 3 C 3, 2 D 2, 4 Slide 122 / 142 35 The inside of the thylakoid is called the and the outside is called the. A B lumen, stroma stroma, lumen Slide 124 / 142 37 Water is split, releasing O 2, in which protein complex? A photosystem I B photosystem II C synthase D NADP reductase Slide 125 / 142 Light Independent Reactions The and NADPH created during the light dependent reactions proceed to the Light Independent Reaction. The light independent reactions are also know as the Calvin Cycle or Dark Reactions. These reactions can occur in light or dark, thus dark reactions is not an accurate name. The Calvin Cycle uses the and NADPHto convert CO2 into Glucose (C6H12 O6) in a multi step process. In 3 turns of the cycle we use 9 and 6 NADPH and 3 CO 2 to make a 3-carbon sugar Slide 126 / 142 Light Independent Reactions
Slide 127 / 142 Light Independent Reactions Slide 128 / 142 The Carbon Cycle To make one 6-carbon glucose molecule: 18 and 12 NADPH and 6 CO2 are required. The Calvin Cycle is also called Carbon Fixing. This means that carbon, a gas in the atmosphere, in the form of CO2, is turned into a solid as a glucose. When glucose is used in respiration, that carbon is then released back into the atmosphere. This process of fixing and releasing carbon is called the Carbon Cycle. Carbon is not being created or destroyed, but cycles through the environment. Slide 129 / 142 Cyclic vs. Noncyclic Energy Transport The Light Reactions produce equal amounts of and NADPH, but the Calvin Cycle use more (18) than NADPH (12) to make a glucose molecule. Slide 130 / 142 38 Carbon dioxide is fixed in the form of glucose in A Krebs cycle B light-dependent reactions C Calvin cycle D cyclic energy transport To have enough, photosynthetic organisms use Cyclic Energy Transport to create the needed. Slide 131 / 142 39 During what stage of photosynthesis are and NADPH coverted to ADP + P i and NADP +? A light dependent reactions B light independent reactions C photosystem I D photosystem II Slide 132 / 142 40 Which of the following statements about photosynthesis is true? The light dependent reactions can only occur in the A light, the light independent reactions can only occur in the dark. Cyclic energy transport is more efficient at B producing glucose than noncyclic energy transport. The light dependent reactions produce which is C used to power the Calvin cycle. D Cyclic energy transport occurs only in bacteria.
Slide 133 / 142 41 The Calvin cycle is an anabolic pathway. True False Slide 134 / 142 Global Climate Change The carbon cycle plays a key role in Global Climate Change. Photosynthesis releases oxygen into the air, but also takes CO 2 out of the air. CO 2 is a greenhouse gas, it absorbs infrared light that would otherwise carry heat away from Earth, into space; cooling Earth. Slide 135 / 142 Global Climate Change If it were not for CO 2, and other greenhouse gases, Earth would be far colder, perhaps too cold to support life as we know it. Greenhouse gases are essential for life. However, the amount of greenhouse gases in Earth's atmosphere is critical to maintaining a constant average temperature for the planet. Slide 136 / 142 Global Climate Change A great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years; effectively taking that carbon out of the carbon cycle. That reduced the CO 2 in the atmosphere, reducing the temperature of Earth by allowing more heat to leave, leading to our current temperature. Slide 137 / 142 Global Climate Change Slide 138 / 142 Global Climate Change The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that long-dead plant and animal life. As we burn those fuels, we are releasing CO 2 back into the atmosphere, increasing the greenhouse gases in the atmosphere. As a result, more heat is being trapped in our atmosphere; the balance of energy brought to Earth by solar energy, and released from Earth in infrared radiation is being changed. This is causing Earth's average temperature to rise. The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily. But it is projected that there will be massive changes in climate in the future, with accompanying changes in sea level, crops, plant and animal life, etc.
Slide 139 / 142 42 Greenhouses gases are dangerous and should be reduced as much as possible. True False Slide 140 / 142 43 Carbon was used from the carbon cycle, reducing CO 2 in the air, as A the amount of life on Earth decreased B as animals died and were buried under earth C fermentation began D All of the above E None of the above Slide 141 / 142 Slide 142 / 142 44 A very warm winter in New Jersey this year would indicate that global climate change is occurring. True False