Final Demonstration Teaching Maricel A. Marcelo, LPT, MAED Instructor Allan Jay C. Allauigan Student Teacher Put a lable on me! Mechanics: 1.) Observe the diagram of the mitochondrion on the tarp. 2.) Identify and label the missing parts using the given pointers. 3.) Once finished, compare your answers with the correct labels provided by the teacher. Put a lable on me! Answers: 1. 2. 3. 4. 5. DNA Ribosome Inner membrane Cristae Outer membrane Learning Objectives At the end of the lesson, the stutent should be able to; Recall the structure and function of mitochondria. Explain the process of cellular respiration and ATP production in the mitochondrion. Demonstrate the correct labelling of mitochondrial structures using a diagram or model. Recognize the significance of mitochondrial function in overall cellular health. The discovery of mitochondria The discovery of mitochondria began in the mid-1800s when scientists observed granules in cells. By the late 19th century, researchers like Albert von Kölliker and Richard Altmann identified these structures, with Carl Benda later coining the term "mitochondria." Throughout the 20th century, significant advancements were made in understanding mitochondrial functions, including the identification of enzymes involved in cellular respiration and the role of ATP. The endosymbiotic theory was revived in the 1960s by Lynn Margulis, who proposed that mitochondria originated from independently living bacteria that were engulfed by another cell. This theory is now widely accepted and has greatly influenced our understanding of cellular evolution. What is Mitochondrion? The mitochondrion, often referred to as the powerhouse of the cell, plays a crucial role in energy production through aerobic metabolism. It is a double-membraned organelle found in most eukaryotic cells, responsible for generating adenosine triphosphate (ATP), the energy currency of the cell. Understanding its structure and function is essential for biology students and professionals interested in cellular metabolism. Structure of Mitochondria Outer Membrane: This is the outer layer that surrounds the mitochondrion. It lets small molecules pass through but blocks large proteins. Intermembrane Space: The space between the outer and inner membranes. It's important for making energy. Inner Membrane: This membrane has many folds called cristae. These folds increase the surface area for chemical reactions. It blocks most molecules, keeping the inside environment just right for making energy. Ribosome: Ribosomes are complex molecular machines found within all living cells. They are responsible for synthesizing proteins by translating messenger RNA (mRNA) into amino acid sequences. Ribosomes can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum, forming rough ER. DNA (Deoxyribonucleic Acid): DNA is the molecule that carries the genetic instructions for the growth, development, functioning, and reproduction of all known living organisms and many viruses. It consists of two long strands forming a double helix, with each strand made up of nucleotides that include a phosphate group, a sugar group, and a nitrogen base. Matrix: In biological contexts, the matrix refers to the extracellular matrix (ECM), a network of proteins and other molecules outside the cells that provide structural and biochemical support to surrounding cells. In a broader sense, a matrix can also refer to an environment or medium in which something develops or is contained. Cristae: The folds of the inner membrane. They contain the proteins and molecules needed to make energy. Function of mitochondria ATP Production: Mitochondria generate ATP (adenosine triphosphate) through a process called oxidative phosphorylation. This involves the electron transport chain and ATP synthase, which harness the energy from electrons to produce ATP, the cell's main energy currency. Cellular Respiration: Mitochondria are central to cellular respiration, a series of metabolic processes that convert biochemical energy from nutrients into ATP, while releasing waste products like carbon dioxide and water. Calcium Storage: Mitochondria store and regulate calcium ions (Ca²⁺), which are crucial for various cellular functions, including muscle contraction, signal transduction, and cellular metabolism. Apoptosis Regulation: Mitochondria play a significant role in apoptosis, or programmed cell death. They release cytochrome c and other factors that activate cell death pathways, helping to maintain healthy cell turnover and tissue homeostasis. Heat Production: In brown adipose tissue, mitochondria help generate heat through a process called thermogenesis. This is particularly important for maintaining body temperature in cold environments. Metabolic Functions: Mitochondria are involved in various metabolic pathways, including the citric acid cycle (Krebs cycle) and fatty acid oxidation, which contribute to the overall energy metabolism of the cell. What would happen if there were no mitochondria in a cell? Anaerobic Metabolism in the Mitochindrion What is anaerobic metabolism? Anaerobic Metabolism Anaerobic metabolism is a type of energy production that occurs without oxygen. It is used by cells when oxygen is scarce, such as during intense exercise or in environments lacking oxygen. This process happens in the cytoplasm and involves the breakdown of glucose to produce energy in the form of ATP (adenosine triphosphate). Key processes of Anaerobic Metabolism Glycolysis: This is the first step, common to both aerobic and anaerobic metabolism. During glycolysis, one molecule of glucose (a six-carbon sugar) is broken down into two molecules of pyruvate (a three-carbon compound). This process produces a net gain of two ATP molecules and two NADH molecules. Fermentation: Since there's no oxygen to proceed to the Krebs cycle and oxidative phosphorylation in the mitochondria, pyruvate undergoes fermentation in the cytoplasm. There are two main types of fermentation: Lactic Acid Fermentation: In muscle cells and some bacteria, pyruvate is converted into lactic acid. This process regenerates NAD+, allowing glycolysis to continue. The buildup of lactic acid in muscles can cause fatigue and soreness. Glucose → 2 Lactic Acid + 2 ATP Alcohol Fermentation: In yeast and some types of bacteria, pyruvate is converted into ethanol and carbon dioxide. This process also regenerates NAD+, allowing glycolysis to continue. Glucose → 2 Ethanol + 2CO2 + 2 ATP Why does anaerobic metabolism doesn’t occur in mitochondria? ATP production in Mitochondria What is ATP? ATP, or adenosine triphosphate, is the cellular “energy currency,” and mitochondria are like the power plants that generate it. The process of ATP production in mitochondria is known as oxidative phosphorylation, and it takes place primarily in the inner mitochondrial membrane. Key steps in ATP production Glycolysis - Glycolysis is the first step in the process of ATP (adenosine triphosphate) production. It takes place in the cytoplasm of the cell and involves the breakdown of glucose (a six-carbon sugar) into two molecules of pyruvate (a three-carbon compound). This process results in the production of a small amount of ATP and NADH (an electron carrier). Pyruvate Oxidation - Pyruvate oxidation is a key step in ATP production where pyruvate, generated from glycolysis, is converted into acetyl-CoA in the mitochondria. This process releases carbon dioxide and produces NADH, which carries electrons to the electron transport chain for further ATP generation. Citric Acid Cycle ( Krebs Cycle ) - The citric acid cycle, also known as the Krebs cycle, is a series of chemical reactions in the mitochondria where acetyl-CoA is broken down. This process generates NADH and FADH2, which carry electrons to the electron transport chain for ATP production, and also produces a small amount of ATP and releases carbon dioxide. - The electron transport chain (ETC) is a series of protein complexes located in the inner mitochondrial membrane. It transfers electrons from NADH and FADH2 to oxygen, creating a flow of protons across the membrane. This proton gradient drives ATP synthase to produce ATP, the cell's energy currency. - Chemiosmosis is the process by which protons (H+) flow down their gradient through ATP synthase, a protein in the inner mitochondrial membrane. This flow of protons drives ATP synthase to produce ATP from ADP (adenosine diphosphate) and inorganic phosphate, generating the energy cells need. Oxygen’s Role -In ATP production, oxygen acts as the final electron acceptor in the electron transport chain. It combines with electrons and protons to form water, which allows the electron transport chain to continue functioning and ultimately drives the production of ATP. What is the significance of mitochondrial biogenesis? Mitochondrial Biogenesis - Mitochondrial biogenesis refers to the process by which new mitochondria are formed in the cell. Mitochondria are often referred to as the "powerhouses" of the cell because they generate the energy needed for various cellular functions. During mitochondrial biogenesis, existing mitochondria grow, replicate their DNA, and divide to produce new mitochondria. This process is essential for maintaining proper cellular function, especially in response to increased energy demands or during adaptation to environmental changes. Mitochondrial Disfunction Mitochondrial dysfunction occurs when mitochondria, the cell's energy factories, do not work as they should. This can lead to a variety of health issues because cells can't produce enough energy to function properly. Here are some key points about mitochondrial dysfunction: • • Causes: It can result from genetic mutations, environmental factors, infections, or adverse effects of certain drugs. Symptoms: Symptoms vary widely but can include muscle weakness, fatigue, neurological problems, and organ dysfunction. • Affected Areas: It often affects high-energy-demand organs like the brain, muscles, heart, and lungs. • Diagnosis: Diagnosing mitochondrial dysfunction can be complex and may involve genetic testing, muscle biopsies, and other specialized tests. • Treatment: While there is no cure, treatments focus on managing symptoms and may include dietary changes, supplements, and medications to support mitochondrial function. Role of Mitochondria in Apoptosis Mitochondria play a pivotal role in apoptosis, which is a process of programmed cell death essential for maintaining healthy tissues and organs. • Release of Cytochrome c: When a cell receives signals to undergo apoptosis, the mitochondria release cytochrome c into the cytoplasm. This protein helps form the apoptosome, a complex that activates caspases—enzymes that dismantle the cell. • Mitochondrial Outer Membrane Permeabilization (MOMP): This process involves the formation of pores in the outer mitochondrial membrane, allowing cytochrome c and other pro-apoptotic factors to escape into the cytoplasm. • Regulation by Bcl-2 Family Proteins: Proteins from the Bcl-2 family regulate mitochondrial membrane permeability. Pro-apoptotic members (such as Bax and Bak) promote membrane permeabilization, while antiapoptotic members (such as Bcl-2 and Bcl-xL) inhibit it. • Apoptotic Signaling Pathways: Mitochondria are involved in intrinsic apoptotic signaling pathways, which are triggered by internal stress signals such as DNA damage, oxidative stress, or other cellular insults. Mitochondrial Genetics Mitochondrial genetics is the study of the genetic material found in mitochondria, which are the energy-producing organelles within cells. Unlike nuclear DNA, mitochondrial DNA (mtDNA) is inherited exclusively from the mother. • Structure: Mitochondrial DNA is a circular molecule, distinct from the linear DNA found in the cell nucleus. It contains 37 genes, which are essential for mitochondrial function. • Inheritance: mtDNA is passed down maternally, meaning it is inherited from the mother. This non-Mendelian inheritance pattern allows researchers to trace maternal lineage and study population genetics. • Mutations: Mutations in mtDNA can lead to various mitochondrial diseases, which often affect high-energy-demand tissues like muscles and the nervous system. • Role in Disease: Mitochondrial genetics plays a crucial role in understanding and diagnosing mitochondrial disorders, which can result from defects in mtDNA or nuclear genes that encode mitochondrial components. Mitochondrion Puzzle Challenge Mechanics: 1.) Form a small group consisting of 4-5 member and recieve a set of puzzle pieces. 2.) Work together to assemble the puzzle to reveal the labeled mitochondrion diagram. 3.) You were only given 10 munites to assemble the puzzle. 4.) The first group to correctly complete the puzzle wins the challenge. Quiz: 1. What is the primary function of the mitochondrion? a) Protein synthesis b) Cellular respiration c) Photosynthesis d) Cell division 2. Which part of the mitochondrion is responsible for producing ATP? a) Outer membrane b) Inner membrane c) Matrix d) Cristae 3. Mitochondria are often referred to as: a) The powerhouses of the cell b) The garbage collectors of the cell c) The architects of the cell d) The messengers of the cell 4. The inner membrane of the mitochondrion is folded into structures called: a) Grana b) Thylakoids c) Cristae d) Ribosomes 5. The space between the inner and outer membranes of the mitochondrion is called: a) Stroma b) Cytosol c) Intermembrane space d) Matrix 6. Which process occurs in the matrix of the mitochondrion? a) Glycolysis b) Calvin Cycle c) Citric Acid Cycle (Krebs Cycle) d) Electron transport chain 7. Mitochondria have their own: a) Ribosomes b) DNA c) RNA d) All of the above 8. The endosymbiotic theory suggests that mitochondria originated from: a) Bacteria b) Viruses c) Fungi d) Algae 9. Which of the following is NOT a function of the mitochondrion? a) Detoxification of reactive oxygen species b) Apoptosis regulation c) Energy production d) Protein synthesis 10. The primary molecule produced by mitochondria that provides energy for cellular activities is: a) Glucose b) ATP (Adenosine triphosphate) c) DNA d) Lipids Assignment: Do an advanced reading about the topic "Chloroplast and Photosynthesis, and the Genetics Systems of Mitochondria and Chloroplast". "Fuel your ambitions with the power of your inner mitochondria—tiny yet mighty, just like your potential"
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