Cell Energy Transformations Notes PDF
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This document provides notes on cell energy transformations and related biological processes including the role of ATP. It includes diagrams and figures to illustrate the concepts. The document is suitable for high school biology.
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Cell Energy Transformations Notes Target Set 3 Metabolism, Energy, and Life -The chemistry of life is organized into metabolic pathways -Organisms transform energy from organic nutrients, sunlight, or inorganic chemicals -The energy transformations of life are subject to the two laws of ther...
Cell Energy Transformations Notes Target Set 3 Metabolism, Energy, and Life -The chemistry of life is organized into metabolic pathways -Organisms transform energy from organic nutrients, sunlight, or inorganic chemicals -The energy transformations of life are subject to the two laws of thermodynamics 1st Law of Thermodynamics: Energy is neither created or destroyed 2nd Law of Thermodynamics: When energy changes form the entropy(disorder) of the surroundings increases. Metabolism, Energy, and Life -Organisms live at the expense of free energy Free energy is necessary to drive endergonic(absorb energy) metabolic reactions Free energy is released from exergonic(release energy) metabolic reactions Metabolic Disequilibrium ○ Energy Coupling:Exergonic reactions fuel endergonic reactions 3.1 I can identify ATP (adenosine triphosphate) as the main unit of energy for cellular work. (Textbook: Chapter 8.1) ATP powers cellular work by coupling exergonic reactions to endergonic reactions Mechanical Work: movement and contraction Transport Work: moving substances across membranes Chemical Work: providing the activation energy for enzyme catalyzed reactions 3.1 I can identify ATP (adenosine triphosphate) as the main unit of energy for cellular work. (Textbook: Chapter 8.1) ATP is the main energy intermediate of life throughout the biosphere Producers convert and store the energy in sunlight or inorganic chemicals into the bond between ADP(Adenosine Diphosphate) and a phosphate group which creates ATP(Adenosine triphosphate) Consumers convert and store the energy in nutrients into the bond between ADP(Adenosine Diphosphate) and a phosphate group which creates ATP(Adenosine triphosphate) 3.1 I can identify ATP (adenosine triphosphate) as the main unit of energy for cellular work. (Textbook: Chapter 8.1) The Structure of ATP… Ribose (5 pentose sugar) Adenine (nitrogenous base) 3 Phosphate (PO4) groups Since all three phosphate groups are negatively charged, high potential energy bonds are required to keep them attached to the molecule 3.1 I can identify ATP (adenosine triphosphate) as the main unit of energy for cellular work. (Textbook: Chapter 8.1) Creatine Phosphate (CP) Creatine Phosphate (CP) gives up its phosphate to ADP such that ADP can be recharged into ATP Creatine Phosphate may also be used for immediate energy needs Creatine supplements are popular among athletes because they allow more ADP to be recharged 3.1 I can identify ATP (adenosine triphosphate) as the main unit of energy for cellular work. (Textbook: Chapter 8.1) Phosphorylation of ADP… Phosphocreatine and ADP anabolically combine to form ATP for temporary energy storage ATP synthase is the enzyme which lowers the activation energy of this reaction 3.1 I can identify ATP (adenosine triphosphate) as the main unit of energy for cellular work. (Textbook: Chapter 8.1) ATP/ADP Cycle The catabolism(hydrolysis) of ATP into ADP and a phosphate group The anabolism (dehydration synthesis:phosphorylation) of ATP from ADP and phosphocreatine This is a cycle ADP can be reused over and over again like an enzyme 3.1 I can identify ATP (adenosine triphosphate) as the main unit of energy for cellular work. (Textbook: Chapter 8.1) Let’s do the math… The catabolism of glucose liberates 686 Calories per mole The anabolism of ATP stores ~7 Calories per mole Most cellular reactions require less than 1 Calorie per mole Efficiency Cellular respiration transfers the energy from glucose into 30-36ATP 36 ATP X 7 Cal/mole= 252 Cal/mole (252 ÷ 686) X100=37% Energy efficiency Where did the other energy go? 3.2 I can explain how cells transform energy (ultimately obtained from the sun) from one form to another through the process of photosynthesis. (Textbook: Chapter 8.2-8.3) Light energy from the sun is converted and stored as chemical energy in the bond formed between ADP and P 3.2 I can explain how cells transform energy (ultimately obtained from the sun) from one form to another through the process of photosynthesis. (Textbook: Chapter 8.2-8.3) The leaf is the main organ in plants where photosynthesis occurs within the leaf the mesophyll layer is composed of mesophyll cells inside the mesophyll cells are chloroplast organelles chloroplasts are the main site of photosynthesis I3.3I can explain how plants acquire matter necessary for growth and development.(Textbook: Chapter 8.2-8.3) Plants acquire water through their roots and carbon dioxide through the stomata on their leaves Additional nutrients such as nitrogen and phosphorus are obtained by plants through the soil I3.4I can identify the reactants and products in the general reaction of photosynthesis. (Textbook: Chapter 8.2-8.3) Photosynthesis can be broken down into two main intermediate reactions Photolysis(Light Dependent:Catabolic) Calvin Cycle(Light Independent:Anabolic) I3.4I can identify the reactants and products in the general reaction of photosynthesis. (Textbook: Chapter 8.2-8.3) Photolysis(Light Dependent:Catabolic) Depend upon light energy to excite the electrons of pigments(Chlorophyll and Carotenoids) The chemical energy released by the excited electrons is used to split water molecules releasing oxygen (O2) as a waste product The chemical energy released from splitting water is used to create ATP reactions Leftover hydrogen(H+ which is carried by NADPH) and ATP created from photolysis is used to build glucose I3.4I can identify the reactants and products in the general reaction of photosynthesis. (Textbook: Chapter 8.2-8.3) Calvin Cycle(Light Independent:Anabolic) Using the ATP and H+ (Carried by NADPH) from the photolysis reaction along with CO2 from the atmosphere to form glucose The chemical energy from ATP becomes stored in the chemical bonds within the glucose molecule RUBISCO: the enzyme and incidentally the most abundant protein in the world responsible for lowering the activation energy of the first phase:carbon fixation in the Calvin Cycle I3.4I can identify the reactants and products in the general reaction of photosynthesis. (Textbook: Chapter 8.2-8.3) Photolysis Light Energy + H2O + ADP + Pi + NADP+→ATP + NADPH +O2 Calvin Cycle ATP + NADPH +CO2→C6H12O6+ ADP + Pi + NADP+ Photosynthesis 6H2O + 6CO2→ C6H12O6 + 6O2 3.5 I can explain that the role of pigments is to absorb light energy in photosynthesis.(Textbook: Chapter 8.2-8.3) Accessory pigments absorb the other wavelengths of light not absorbed by chlorophyll (GBIV) The excited electrons of the accessory pigments are passed on to chlorophyll, exciting its electrons When plants stop making chlorophyll, the colors of the accessory pigments are unmasked/become visible Examples: -Carotenoids: reflect orange and yellow -Anthocyanins: only produced in the fall reflect red with the addition of sugars -Tannins: reflect brown 3.5 I can explain that the role of pigments is to absorb light energy in photosynthesis.(Textbook: Chapter 8.2-8.3) BIV Absorption Blue, indigo and violet have the shortest wavelengths Shortest wavelengths produce the greatest excitation of electrons More excited electrons = more ATP Plants can’t afford NOT to absorb blue RED LIGHT & REFLECTION If light is not immediately absorbed by the chloroplast, it is reflected by other objects in the environment When light “bounces back”, it does so at a longer wavelength (red) The amount of reflected red light is plentiful 3.6 I can explain why leaves change color in the fall, as plants reabsorb chlorophyll and light is reflected by the accessory pigments. (Textbook: Chapter 8.2-8.3) Chlorophyll requires a great deal of ATP and water to synthesize In the fall, there is less water available to make chlorophyll and less available light to use for synthesis As a result, leaves stop producing chlorophyll and the underlying pigments are exhibited I3.7I can describe how the structure of a leaf relates to its ability to photosynthesize.(Textbook: Chapter 8.2-8.3) Large surface area for light absorption Stoma on the underside of the leaf for CO2 absorption, O2 removal, and H2O loss via transpiration I3.7I can describe how the structure of a leaf relates to its ability to photosynthesize.(Textbook: Chapter 8.2-8.3) Evolution by means of natural selection(Carbon fixation alternatives).... Most plants are identified as C3 plants ○ C3 plants have adapted measures of water conservation which close their stomata in hot, arid conditions ○ The problem that results is an oxygen buildup which causes RUBISCO to initiate photorespiration instead of photosynthesis Solution:C4 and CAM plants ○ C4 plant(Avoid O2): unique leaf structure and alternate mode of carbon fixation using four carbon compound to avoid photorespiration (EX: Grasses: Corn and Sugarcane) ○ CAM plant (Avoid H2O loss): also utilize the C4 plant pathway and keep their stomata closed and perform the calvin cycle during the day(Ex: Cacti and pineapple plants) 3.8 I can explain how cells transform energy (ultimately obtained from the sun) from one form to another through the process of cellular respiration. (Textbook: Chapter 9.1-9.2) The majority of energy harnessed on earth starts with the sun.. Organisms performing cellular(aerobic) respiration or anaerobic respiration consume biomatter filled with nutrients ultimately synthesized indirectly from solar energy 3.9 I can explain how animals acquire matter necessary for growth and development.(Textbook: Chapter 9.1-9.2) Animals acquire matter and energy necessary for growth and development based on their niche within the food web Ex: Primary consumers eat producers, secondary consumers eat primary consumers, etc 3.10 I can identify the reactants and products in the general reaction of aerobic cellular respiration. (Textbook: Chapter 9.1-9.2) 1st Step of Respiration: Glycolysis (Splitting of Glucose) C6H12O6 + 2ATP + 4ADP + 4Pi → 2C3H4O3 + 4ATP + 2ADP + 2Pi Net: Glucose→2 Pyruvates + 2ATP This reaction takes place in the cytoplasm(cytosol) of every organism performing aerobic or anaerobic(fermentation) respiration 3.10 I can identify the reactants and products in the general reaction of aerobic cellular respiration. (Textbook: Chapter 9.1-9.2) 2nd Step of Cellular(Aerobic) Respiration: Formation of Acetyl Coenzyme A 2Pyruvate→2Acetyl CoA + 2CO2 This step occurs in the presence of oxygen (O2) This is the first step of aerobic respiration in the mitochondria 3.10 I can identify the reactants and products in the general reaction of aerobic cellular respiration. (Textbook: Chapter 9.1-9.2) 3rd Step of Cellular(Aerobic) Respiration: Citric Acid Cycle (Krebs Cycle) 2 Acetyl CoA + 2ADP + 2Pi→ 4CO2 + 2ATP Energy intermediates NADH and FADH2 are produced and are used in the 4th step of cellular(aerobic) respiration Occurs in the mitochondrial matrix 3.10 I can identify the reactants and products in the general reaction of aerobic cellular respiration. (Textbook: Chapter 9.1-9.2) 4th Step of Cellular(Aerobic) Respiration: Electron Transport Chain and Oxidative Phosphorylation 6O2 + ADP + Pi→ 6H2O + ATP Occurs in the intracellular matrix of the mitochondria The majority of the ATP is produced during this step. The amount of ATP produced varies, but most sources confirm the production of around 28-34 ATP molecules. 3.10 I can identify the reactants and products in the general reaction of aerobic cellular respiration. (Textbook: Chapter 9.1-9.2) Cellular (Aerobic) Respiration Summary C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP What to know… Glycolysis splits apart glucose to produce 2 net ATP molecules Formation of Acetyl CoA, the Krebs Cycle, the Electron Transport Chain, and Oxidative Phosphorylation use oxygen to produce ATP molecules and the waste products carbon dioxide and water 3.11 I can identify that glucose is the main molecule of energy storage and utilization for life.(Textbook: Chapter 9) Proteins, Fats, and Carbohydrates can all be broken down to yield ATP via Cellular Respiration Ultimately, glucose provides the most efficient pathway to ATP production 3.12 I can distinguish between aerobic respiration and anaerobic respiration, comparing energy yields and complexity of the products.(Textbook: Chapter 9) Cellular(Aerobic) Respiration & ATP The waste byproducts of aerobic respiration are simpler (CO2) Therefore, more energy is available to recharge ATP from ADP and Creatine Phosphate As a result of this higher efficiency, aerobic organisms can be more complex, active and have longer-life spans. 3.12 I can distinguish between aerobic respiration and anaerobic respiration, comparing energy yields and complexity of the products.(Textbook: Chapter 9) What if an organism does not have access to oxygen or it lacks the cellular machinery to utilize oxygen? Lactic Acid Fermentation Products: 2Lactic Acid +2 ATP Alcoholic Fermentation Products: 2Ethanol + 2CO2 +2ATP Why is the alcoholic fermentation advantageous to brewers/vintners and bakers? 3.13 I can explain the interrelated nature of photosynthesis and cellular respiration. (Textbook: Chapter 9.1) Question #1 Interdependence… Can you explain the interdependence between photosynthetic organisms and respiring organisms? 3.13 I can explain the interrelated nature of photosynthesis and cellular respiration. (Textbook: Chapter 9.1) Question #2 Interdependence… Can you explain the interdependence between the process of photosynthesis and the process of cellular respiration? Draw an organism that rotates between the two processes. Drawing #3 Draw an organism in action rotating between the process of fermentation and cellular respiration.