Photosynthesis and Cellular Respiration PDF

Bioenergetics Energy of Life If it goes down to one thing, what do living things need the most? Bioenergetics The study of energy in living systems (environments) and the organisms (plants and animals) that...

Bioenergetics Energy of Life If it goes down to one thing, what do living things need the most? Bioenergetics The study of energy in living systems (environments) and the organisms (plants and animals) that utilize them. Energy ability to do work all living things require energy can be transformed from one form to another 1. Kinetic Energy Energy of Motion Heat and light energy are examples 2. Potential Energy Solar, Chemical and Mechanical Solar, chemical, mechanical are some ways by which energy can be converted from one form to another. Two Types of Energy Reactions 1. Endergonic Reactions 2. Exergonic Reactions Endergenic Exergonic Chemical reaction that Chemical reaction that requires a net input of releases energy energy. Ex: Photosyntesis Ex: Cellular Respiration Light SUN Energy 6CO2 + 6H2O C6H12O6 + 6O2 C6H12O6 + 6O2 6CO2 + 6H2O+ ATP What is Metabolism? The sum total of the chemical activities of a cell. There are two Types: 1. Anabolic Pathway 2. Catabolic Pathway Anabolic Catabolic Metabolic reactions, Metabolic reactions which consume energy which release energy (endergonic), to build (exergonic) by breaking complicated molecules down complex molecules from simpler in simpler compounds compounds. Ex: Photosynthesis Ex: Cellular Respiration Energy Giving Molecule ATP (Adenosine triphosphate) store smaller amounts of energy, but each molecule releases enough energy to do the work within the cell. Cellular Energy Components Breaking the Bonds of ATP n Process is called n Occurs continually in cells n Enzyme can weaken & break releasing energy & free PO4 How does ATP work ? n Organisms use to break down to release its potential energy n This energy is trapped and stored in the form of n Itis estimated that will generate and consume approximately Coupled Reaction - ATP The of is coupled with the by a to another molecule. Photosynthesis  What exactly is Photosynthesis? It is a biological process that converts light energy into chemical energy, which fuels the metabolism of photosynthetic organisms It is the chemical process that plants use to create glucose from sunlight, carbon dioxide and water. Photosynthesis takes place in leaves, within specialised structures called chloroplasts. Inside chloroplasts are chlorophyll—green photosynthetic pigment whose job is to absorb sunlight. Think About It! If chlorophyl is a green pigment, why are there plant leaves with different colors?  2 GROUP OF PIGMENTS (PLANTS) – are green pigments that absorbs all wavelengths of 1) CHLOROPYLLS light in the red, blue, and violet ranges. 2) CAROTENOIDS Carotenoids – are yellow, orange and red pigments. Phycobilins – The pigment found in red algae which give them their reddish color absorb light in blue and green ranges. Photosynthesis Is often regarded as the most important life process on earth Reactants carbon dioxide water The reactants of CO2 H2 O photosynthesis are carbon dioxide and water. Products oxygen glucose Its products are O2 C 6H12 O6 oxygen and glucose. Chlorophyll and sunlight are neither reactants nor products. They are not used up or created in the process.  How does it actually work? The chloroplast is are cell organelles found in plants and algae Thylakoid - a membrane-bound compartment in chloroplasts and cyanobacteria that is involved in photosynthesis  Stages of Photosynthesis 1.) STAGE I - light-dependent reactions Directly use the light energy to produce ATP and NADH. STAGE II - light-independent reactions Also called CALVIN CYCLE, the ATP and NADPH from light reactions are used to create glucose.  Stage 1- Light Dependent Reaction The light-dependent reactions of This process splits water molecules, photosynthesis occur in the releasing oxygen as a byproduct thylakoid membranes of while generating a proton gradient chloroplasts, where chlorophyll that drives ATP synthesis through absorbs sunlight, exciting electrons ATP synthase and produces that are then passed through an NADPH by reducing NADP+with electron transport chain. high-energy electrons through the NADP+ reductase.  Stage 2- Light Independent Reaction The Second stage of photosynthesis happens in the stroma surrounding the thylakoid in the chloroplast. utilize ATP and NADPH produced during the light-dependent reactions to convert carbon dioxide into glucose. How Plants get their CO2? Plants absorb carbon dioxide CO₂ from the atmosphere through tiny pores on their leaves called stomata. The COthen diffuses into the cells and reaches the stroma of chloroplasts, where it is utilized in the light- independent reactions of photosynthesis.  ‘in the Reactants presence Products of’ chlorophyll carbon dioxide water oxygen glucose sunlight Cellular Respiration Cellular Respiration Is the means by which cells release the stored energy in glucose to make ATP. The site for this process is the cytoplasm and mitochondria. General Formula for Cellular Respiration C6H12O6 + 6O2 6CO2 + 6H2O+ ATP Cellular Respiration has three stages: Glycolysis, Kreb Cycle, and the Electron Transport Chain. Stage 1- Glycolysis Glycolysis is the metabolic pathway that breaks down one molecule of glucose into two molecules of pyruvate, occurring in the cytoplasm of cells. This ten-step process generates a net yield of two ATP molecules and two NADH molecules, which are crucial for energy production and cellular respiration. Stage 1- Glycolysis Additionally, the pyruvate produced can be further utilized in aerobic or anaerobic pathways, depending on the availability of oxygen Stage 2- Kreb Cycle The Krebs cycle, or citric acid cycle, takes place in the mitochondria and uses acetyl- CoA to produce energy. For each turn of the cycle, it creates one ATP , three NADH, and one FADH₂ , while releasing two carbon dioxide molecules as waste. Stage 3- Electron Transport Chain The electron transport chain (ETC) is a series of protein complexes located in the inner mitochondrial membrane that transfers electrons from NADH and FADH₂ , ultimately reducing molecular oxygen to form water. Stage 3- Electron Transport Chain As electrons move through the chain, energy is released, which is used to pump protons across the membrane, creating a proton gradient that drives the synthesis of ATP via ATP synthase. The overall products of the electron transport chain are approximately 28 to 34 ATP molecules and water.  The current balance of oxygen and carbon dioxide in the atmosphere is maintained by... Photosynthesis Respiration carried out by green carried out by plants and other animals and other photosynthetic respiring organisms organisms and and produces produces oxygen. carbon dioxide. What happens to this delicate balance if we continue cutting down trees? How might changing atmospheric carbon dioxide levels affect the rate of photosynthesis?