SECOND QUARTER 2021-2022 SCORE: Biology Cellular Respiration WebQuest Instructions: Use the links provided throughout the quest to help answer the questions. PART I . Cellular Respiration - Introduction 1). What is cellular respiration? A/. Is the process by which organisms combine oxygen with foodstuff molecules. 2). Enumerate the two types of respiration and describe each one. A/. External respiration: is the breathing process. It involves inhalation and exhalation of gases. Internal respiration: involves gas exchange between the blood and body cells. PART II . Overview of Cellular Respiration 3). Enumerate and describe briefly the steps of cellular respiration in the presence of oxygen. A/. Pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation—require oxygen in order to occur. . 4). Enumerate and describe briefly the steps of cellular respiration in the absence of oxygen. How is the process called? A/. That proceeds without oxygen is called anaerobic respiration. After that, living things could use oxygen to break down glucose and make ATP. 5). Enumerate and describe the types of fermentation? A/. Lactic acid fermentation. Yeast strains and bacteria convert starches or sugars into lactic acid, requiring no heat in preparation. PART III. Overview of Glycolysis 6). In glycolysis, what happens to glucose? A/. During glycolysis, glucose ultimately breaks down into pyruvate and energy 7). Is glycolysis an aerobic or anaerobic process? Explain. A/. is an anaerobic process. None of its nine steps involve the use of oxygen. 8). Where does glycolysis occur? A/. Glycolysis takes place in the cytoplasm. Within the mitochondrion . 9). Describe the two main phases of glycolysis. A/. Energy investment phase and energy generation phase. The first stage of the glycolysis pathway. PART IV. Krebs Cycle (Citric Acid Cycle) _ 10). What intermediate step occurs in between glycolysis and the Krebs’ Cycle? A/. The transition reaction connects glycolysis to the citric acid (Krebs) cycle. 11). In which organelle within the cell does this process occur? A/. It begins in the cytoplasm of the cell, with the mitochondria functioning as the main organelle where the rest of the process continues and finishes. 12). Why is an intermediate step needed between glycolysis and the Citric Acid Cycle? A/. The transition reaction converts the two molecules of the 3-carbon pyruvate from glycolysis into two molecules of the 2-carbon . 13). How many ATP molecules are produced during the Krebs Cycle? A/. They need 2 ATP 14). Beside ATP what other molecules are produced during the Krebs Cycle? A/. Molecules called NADH and FADH. 15). What molecule, which is also the product of glycolysis, is transported into the mitochondria to release and capture chemical energy? A/. In eukaryotic cells, the pyruvate molecules produced at the end of glycolysis are transported into mitochondria. PART V. ELECTRON TRANSPORT CHAIN 16). What are the input molecules for the electron transport chain? A/. Glycolysis Cytoplasm 1 Glucose (C6H12O6) 2 ATP Pyruvate -> acetyl-CoA Mitochondria (Matrix) 2 Pyruvate Citric Acid Cycle (Krebs Cycle) Mitochondria (Matrix) 2 Acetyl-CoA Electron Transport Chain (ETC) Mitochondria (Inner Membrane) 6 NADH 2 FADH2 17). As the electrons are transferred from one protein to another in the inner membrane of the mitochondria, the protons (H+) are pumped through the membrane creating a concentration gradient between the mitochondrial matrix and the intermembrane space. What type of energy is represented by the concentration gradient? A/. 18). Why is oxygen needed to complete the production of ATP molecules? A/. Without oxygen, organisms can split glucose into just two molecules of pyruvate. This releases only enough energy to make two ATP molecules. . PART VI. CONCLUSION 19). Write a summary of cellular respiration. In your response: State the function of cellular respiration. Identify the site of each of the phases of cellular respiration. Identify the inputs and outputs of each stage and write the chemical formulas of each. –(10%) (COLLABORATIVE PROJECT – CHEMISTRY) A/. The main function of cellular respiration is to break down glucose to form energy. Glycolysis in the cytoplasm, the Kreb's Cycle in the Mitochondrial Matrix and the Electron Transport Chain in the Mitochondrial Membrane.