Slide 1 / 142 Slide 2 / 142 New Jersey Center for Teaching and Learning Progressive Science Initiative BIOLOGY This material is made freely available at www.njctl.org and is intended for the non- commercial use of students and teachers. These materials may not be used for any Energy Processing commercial purposes without the written permission of the owners. NJCTL maintains its website for the convenience of teachers who wish to make their work available to other teachers, participate in a virtual professional October 2013 learning community, and/or provide access to course materials to parents, students, and others. www.njctl.org Click to go to website: www.njctl.org Slide 3 / 142 Slide 4 / 142 Vocabulary Vocabulary Click on each word below to go to the definition. Click on each word below to go to the definition. Acetyl Co-A noncyclic energy transport electron transport chain aerobic obligate aerobe ethanol fermentation anabolic pathway obligate anaerobe facultative anaerobe oxidation anaerobic FADH 2 oxidative phosphorylation ATP fermentation phosphorylation ATP synthase glycolysis photosynthesis Calvin Cycle Krebs cycle photosystem I catabolic pathway lactic acid fermentation photosystem II cellular respiration light dependent reactions pyruvate chlorophyll light independent reactions pyruvate decarboxylation metabolism citric acid cycle reduction NADH cyclic energy transport thylakoid electron acceptor NADPH Slide 5 / 142 Slide 6 / 142 Chapter 8 Energy Processing Metabolism & ATP Unit Topics Click on the topic to go to that section · Metabolism & ATP Cellular Respiration · · Fermentation · Photosynthesis Return to Table of Contents
Slide 7 / 142 Slide 8 / 142 Metabolic Pathways Metabolic Pathways A metabolic pathway begins with a specific molecule and Metabolism is the totality of an organism’s chemical reactions. ends with a product Metabolism is a property of all life. Each step is catalyzed by a specific enzyme Without enzymes, metabolic pathways would proceed very slowly. enzyme 3 enzyme 1 enzyme 2 B C A D Reaction 1 Reaction 2 Reaction 3 Starting Product Molecule Slide 9 / 142 Slide 10 / 142 Metabolic Pathways Catabolic Pathways There are two types of metabolic pathways: Catabolic pathways break down molecules from the environment. Catabolic pathways Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell Anabolic pathways processes. Slide 11 / 142 Slide 12 / 142 Anabolic Pathways Exergonic Reaction Catabolic pathways are exergonic reactions; the change in Gibbs free energy is negative. Thus, they release Anabolic pathways synthesize complex organic energy and occur spontaneously molecules and power cell processes using the energy derived from catabolic pathways. Examples: building bones Amount of Reactants free building muscle Free energy energy building starch released powering active transport (ΔG < 0) Energy Products Click here for a pneumonic device Progress of the reaction
Slide 13 / 142 Slide 14 / 142 Endergonic Reaction Spontaneous Processes A process will occur spontaneously if the result is a reduction of Anabolic pathways are endergonic reactions; the change the Gibbs Free Energy (G) of the system. in Gibbs free energy is positive. Thus, they require an input of energy and do not occur spontaneously G takes into account the resulting change in the energy of a system and the change in its entropy . If the effect of a reaction is to reduce G, the process will proceed spontaneously. Amount of Free energy Products free energy required If ∆G is negative , the reaction will occur spontaneously. (ΔG > 0) Energy If ∆G is zero or positive , it will not occur spontaneously. Reactants Progress of the reaction Slide 15 / 142 Slide 16 / 142 Free Energy and Metabolism Adding Coupled Reactions Biological systems often need an endergonic reaction to Non-spontaneous reaction: # G is positive occur, but on it's own, it won't proceed spontaneously. NH 2 + To be able to occur, the endergonic reaction is coupled to NH 3 # G = +3.4 kcal/mol Glu a reaction that is exergonic , so that together , they are Glu Glutamic Ammonia exergonic. acid Spontaneous Reaction: ΔG is negative ΔG = -7.3 kcal/mol ATP P i + ADP + H 2 O together, reactions are # G = –3.9 kcal/mol spontaneous Slide 17 / 142 Slide 17 (Answer) / 142 1 A spontaneous reaction _____. 1 A spontaneous reaction _____. A occurs only when an enzyme or other catalyst is present A occurs only when an enzyme or other catalyst is present B cannot occur outside of a living cell B cannot occur outside of a living cell C releases free energy when proceeding in the forward direction C releases free energy when proceeding in the forward direction Answer Answer C D D is common in anabolic pathways is common in anabolic pathways E leads to a decrease in the entropy of the universe E leads to a decrease in the entropy of the universe [This object is a pull tab]
Slide 18 / 142 Slide 18 (Answer) / 142 2 Anabolic pathways are ___________ and catabolic 2 Anabolic pathways are ___________ and catabolic pathways are ______________. pathways are ______________. spontaneous, non-spontaneous spontaneous, non-spontaneous A A endergonic, exergonic endergonic, exergonic B B exergonic, endergonic exergonic, endergonic C C Answer Answer endothermic, endergonic endothermic, endergonic D D B [This object is a pull tab] Slide 19 / 142 Slide 19 (Answer) / 142 3 Which of the following correctly states the relationship 3 Which of the following correctly states the relationship between anabolic and catabolic pathways? between anabolic and catabolic pathways? Degradation of organic molecules by anabolic pathways Degradation of organic molecules by anabolic pathways A A provides the energy to drive catabolic pathways. provides the energy to drive catabolic pathways. Answer Answer Energy derived from catabolic pathways is used to drive the Energy derived from catabolic pathways is used to drive the C B B breakdown of organic molecules in anabolic pathways. breakdown of organic molecules in anabolic pathways. Anabolic pathways synthesize more complex organic Anabolic pathways synthesize more complex organic C C molecules using the energy derived from catabolic pathways. molecules using the energy derived from catabolic pathways. [This object is a pull tab] Slide 20 / 142 Slide 21 / 142 Cell Energy ATP A cell does three main kinds of work: Cells can store the energy from catabolic pathways in a molecule Mechanical (motion) · called ATP (adenosine Transport (crossing a barrier) · triphosphate) . ATP can be Chemical (changing a molecule) · broken down later to fuel anabolic reactions. To do work, cells manage energy resources by energy coupling, using an exergonic reaction to drive an endergonic one
Slide 22 / 142 Slide 23 / 142 ATP ATP ATP (adenosine triphosphate) The phosphate groups repel each includes three phosphate other, since they each have a groups (PO 4-3 ). negative charge. Therefore it requires Work to add the second phosphate group; to go from AMP (monophosphate) to ADP (diphosphate). Each Phosphate group has an To add the third group, to go from ionic charge of -3e. ADP to ATP (triphosphate), requires even more work since it In this model of ATP, each PO 4-3 is repelled by both of the other is circled in blue. phosphate groups. Slide 24 / 142 Slide 25 / 142 ATP ATP This is like the work in The bonds between the phosphate groups of ATP’s tail can compressing a spring. be broken by hydrolysis. The energy from the work needed Energy is released from ATP when the terminal phosphate to bring each phosphate group to bond is broken. the molecule is stored in that phosphate bond. The released energy is equal to the work that was done to form the bond. That work overcame the electrostatic When the bond is broken to go repulsion between the last phosphate group and the initial from ATP to ADP, significant ADP molecule. energy is released. Going from ADP to AMP releases The result is a chemical change to a state of lower free less energy, since there is less energy. total charge in ADP than ATP. Slide 26 / 142 Slide 27 / 142 ATP ATP Performs Work In the living systems, the energy from the exergonic reaction ATP drives endergonic reactions by phosphorylation , of ATP hydrolysis can be used to drive an endergonic transferring a phosphate group to some other molecule, reaction. such as a reactant. Overall, the coupled reactions are exergonic. The recipient molecule is now "phosphorylated". The three types of cellular work are powered by the hydrolysis of ATP.
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