Outline Of The Entire Chapter 6 Metabolism: Energy And Enzymes

Chapter 6 Outline: Energy & EnzymesNameInstitutional Affiliation
Metabolism: Energy & EnzymesLife and the Flow of Energy• The ability to bring about change or do work is referred to as energy. Carrying out normal metabolic activities require constant supply of energy. • Life is supported when cells have sufficient energy supplies. • The energy required by cells helps to carry out important functions such as metabolism, reproduction, growth and development, and response to stimuli. • Organisms obtain their energy from organic sources mostly• The energy is usually photosynthesized by some bacteria, algae and plants. From a wider perspective, solar energy ultimately support life on earth. Forms of energyThere are two forms of energy: Potential: Potential energy is that which cannot be used to complete a task at the moment because it is stored. Kinetic: Is the energy in motion. For instance, when a horse runs through trees or when a stone is thrown into the air, kinetic energy is involved. Note: In the life of every organism, potential energy is stored in the foods they eat. This is so because the energy can later be converted into other types of energy, including kinetic energy. The energy form in foods is referred to as chemical energy; the foods contain organic molecules held by chemical bonds. For instance, when a horse runs, the chemical energy gets transformed to mechanical energy through kinetic energy.The laws of Thermodynamics• Energy flows within the terrestrial ecosystem. • The sun provides the solar energy which is captured in small bits by plants. The captured energy is stored in different forms such as carbohydrates in chemical bonds. • Plants also use a little amount of the energy through cellular respiration, which is dissipated as heat. • In our ecosystem, organisms such as horses obtain food from plants, which are considered the source of food for other organisms. The carbohydrates taken by the horse are then released in form of heat energy after cellular respiration. • Every living thing eventually releases the captured solar energy in form of energy after metabolism occurs. This is an indication that the flow of energy has a pattern in our ecosystem. However, it should be noted that the energy cannot be recycled. • The flow of energy in ecosystems and cells is explained by two laws of thermodynamics o According to the first law, organisms have the ability to convert energy from chemical to mechanical. For example, this law applied during the process of photosynthesis; the cells of a plant utilizes the energy from the sun to convert water, carbon dioxide and other molecules rich in energy to form carbohydrates. As mentioned earlier, some energy captured from the sun is dissipated in form of heat and the rest used to synthesize carbohydrates. In essence, the energy used by plants to produce carbohydrates is obtained from the sun. Furthermore, the solar energy spared is not considered a waste since heat is equally a form of energy. A horse utilizes energy in form of carbohydrates to generate power for the muscles that enable it to move. The energy is produced by the cells in its body, where a portion of it is dissipated to the environment in form of heat.o The other law of thermodynamics applies to other systems of life. There is heat energy released into the environment during the process of photosynthesis. Similarly, both the horse and plants also release extra heat to the surrounding. In essence, the energy released cannot be used to bring about change. In every process of energy transformation, all forms of energy eventually turn to heat energy, which is released to the environment. The released energy in form of heat cannot be recaptured and transformed into other useful forms of energy. The second law of thermodynamics holds that there is no process of energy transformation that is fully efficient. This is because in every step of transformation, there is energy lost in form of heat. A good example is the energy transformation that occurs in automobiles. The process of converting energy from chemical to mechanical is only 20% to 30% efficient. The rest of the energy is lost in form of heat. Cells in organisms has an efficiency level of 40%, with the rest of the energy released as heat. Energy Transformations and Metabolism• All the chemical reactions that occur in a cell amount to cellular metabolism. Cellular metabolism leads to a break down and build of molecules. • The two processes have specific terms:-o Anabolism is a term used to describe the process of buildup of molecules. o Catabolism is term used to describe the process of breaking down molecules.Note: Both anabolism and catabolism are chemical reactions that involve reactants and products. A reactant is a substance utilized in a reaction process, while a product is the result of a reaction. The concept of entropy is used to determine whether a reaction will occur as anticipated; only if the state of the reaction increases the entropy of the universe.• Cell biology focuses on specific reactions as opposed to the entire universe. In this concept scholars prefer to use the term free energy in place of entropy. • Free energy is referred to as the amount of available energy, usually denoted by ΔG. This concept implies that there is energy that can be used to bring about change after a chemical reaction. • When the free energy from the content of the reactants is subtracted from the contents of the product after a reaction, then free energy is obtained. Negative free en...