1.state two difference between glycolysis and krebs cycle
2. Compare between respiration and photosynthesis
3. State two situations where the rate of respiration rises above normal temperature
4. Define the following terms
i) oxygen debt
ii) respirator quotient
5. Two applications of anaerobic respiration
6. State two differences between aerobic and anaerobic
7. Describe the
I) krebs cycle
ii) glycolysis
1. Two differences between glycolysis and Krebs cycle are as follows:
- Glycolysis occurs in the cytoplasm of the cell, whereas the Krebs cycle occurs in the mitochondria.
- Glycolysis breaks down glucose molecules to pyruvate, while the Krebs cycle further breaks down pyruvate to produce energy in the form of ATP through a series of reactions.
2. Respiration and photosynthesis are two processes that are related to energy production in living cells. However, they differ in a few ways, which are as follows:
- Respiration occurs in all living cells, whereas photosynthesis occurs only in autotrophic organisms.
- Respiration releases energy stored in organic molecules in the form of ATP, whereas photosynthesis uses energy from sunlight to convert water and carbon dioxide into glucose and oxygen.
3. Two situations where the rate of respiration rises above normal temperature are:
- During physical exercise or activity, when the body requires more energy to sustain muscle movement.
- During high fever or infection, when the body's metabolic rate increases to fight off the illness.
4. The definitions of the following terms are as follows:
i) Oxygen debt: The amount of oxygen that must be consumed after physical exertion to restore the body's metabolic processes back to normal levels and eliminate the accumulated lactic acid produced during anaerobic respiration.
ii) Respiratory quotient: The ratio of carbon dioxide produced to oxygen consumed during respiration, indicating the type of metabolism (anaerobic or aerobic) or the type of nutrient (carbohydrate, fat, or protein) being used for energy production.
5. Two applications of anaerobic respiration are:
- In the food industry, where anaerobic fermentation is used to produce yogurt, cheese, sauerkraut, and other food products.
- In the medical field, where anaerobic metabolism can be used as a diagnostic tool to detect certain infections or metabolic disorders.
6. Two differences between aerobic and anaerobic metabolism are:
- Aerobic metabolism requires oxygen as a reactant, while anaerobic metabolism does not.
- Aerobic metabolism produces a much larger amount of ATP than anaerobic metabolism (around 36-38 ATP molecules per glucose molecule for aerobic, and only 2 ATP molecules per glucose molecule for anaerobic).
7. The descriptions of the Krebs cycle and glycolysis are as follows:
i) Krebs cycle: A series of biochemical reactions that take place in the mitochondria of eukaryotic cells, where pyruvate molecules produced from glycolysis are further broken down to generate multiple ATP molecules. The Krebs cycle involves a series of enzyme-catalyzed steps, producing electron carriers such as NADH and FADH2 that supply electrons to the electron transport chain for further ATP synthesis.
ii) Glycolysis: The metabolic pathway that breaks down glucose into two pyruvate molecules in the cytoplasm of the cell, producing a small amount of ATP and NADH in the process. It is the first step of both aerobic and anaerobic respiration, and can occur in the absence of oxygen for short periods of time. Glycolysis involves a series of enzyme-catalyzed reactions, including phosphorylation, isomerization, and cleavage of glucose molecules.
1. Two differences between glycolysis and the Krebs cycle are:
- Location: Glycolysis occurs in the cytoplasm of cells, while the Krebs cycle takes place in the mitochondria.
- ATP production: Glycolysis produces a net gain of 2 ATP molecules, while the Krebs cycle produces 2 ATP molecules directly and also generates high-energy carrier molecules (NADH and FADH2) that can be used to produce more ATP in subsequent steps.
2. Comparison between respiration and photosynthesis:
- Energy source: Respiration is a process that releases energy from organic molecules to produce ATP, using oxygen as the final electron acceptor. Photosynthesis, on the other hand, is a process that converts light energy into chemical energy, producing organic molecules and releasing oxygen as a byproduct.
- Carbon dioxide and oxygen: Respiration consumes oxygen and produces carbon dioxide as waste, while photosynthesis consumes carbon dioxide and releases oxygen as a byproduct.
3. Two situations where the rate of respiration rises above normal temperature are:
- Exercise: When engaging in physical exercise, the body's demand for energy increases, leading to an increase in the rate of respiration to meet the energy needs of the muscles.
- Fever: During a fever, the body's temperature rises above normal, and as a result, the rate of respiration increases as the body tries to maintain homeostasis.
4. Definitions of the following terms:
i) Oxygen debt: Oxygen debt refers to the amount of additional oxygen that the body needs to repay to restore normal levels of ATP and remove accumulated waste products, such as lactic acid, after strenuous exercise.
ii) Respiratory quotient: Respiratory quotient (RQ) is the ratio of the volume of carbon dioxide produced to the volume of oxygen consumed in a specific metabolic process or during respiration. It represents the type of fuel being metabolized, with different values indicating the predominant fuel source (e.g., carbohydrates, fats, or proteins).
5. Two applications of anaerobic respiration:
- Industrial fermentation: Anaerobic respiration is utilized in industrial processes such as the production of alcoholic beverages, bread-making, and the production of certain dairy products like yogurt.
- Biogas production: Anaerobic respiration is also used in the production of biogas, where organic waste materials are broken down by bacteria in an anaerobic environment to produce methane, which can be used as a renewable energy source.
6. Two differences between aerobic and anaerobic respiration:
- Oxygen requirement: Aerobic respiration requires oxygen, while anaerobic respiration does not rely on oxygen.
- Energy production: Aerobic respiration produces a higher yield of ATP per glucose molecule compared to anaerobic respiration. Aerobic respiration results in the complete oxidation of glucose, while anaerobic respiration stops at an incomplete oxidation stage, leading to the production of lactic acid or other byproducts.
7. Descriptions of:
i) Krebs cycle: The Krebs cycle, also known as the citric acid cycle or the tricarboxylic acid (TCA) cycle, is a series of chemical reactions that occurs in the mitochondria of cells. During the cycle, acetyl-CoA, which is formed from the breakdown of glucose, is oxidized to produce carbon dioxide, generating high-energy electron carriers (NADH and FADH2) and ATP. The Krebs cycle is a key metabolic pathway involved in the production of energy-rich molecules used by the cell.
ii) Glycolysis: Glycolysis is the initial step in both aerobic and anaerobic respiration. It takes place in the cytoplasm of cells. During glycolysis, a molecule of glucose is split into two molecules of pyruvate, resulting in the production of a small amount of ATP and high-energy electron carriers (NADH). Glycolysis is an anaerobic process and does not require oxygen.