Biology Unit 2 IP Essays

Biology Unit 2 IP Essays Biology Unit 2 IP Paper Biology Unit 2 IP Paper All organisms are usually divided into the two large categories, according to the substances they use to produce energy. While autotrophs use non-organic elements (sunlight), heterotrophs require food to produce energy. Autotrophs are the â€Å"organisms that can make their own food from an inorganic source of carbon given a source of energy† (Blankenship, 2002). The majority of plants and algae are autotrophic by nature; i.e., they use photosynthesis to produce glucose.   Ã‚   2. What are the names for the types of organisms can use Aerobic Cellular Respiration to break down glucose to produce ATP? Provide specific examples. All active organisms utilize the benefits of aerobic cellular respiration process to produce energy. In other terms, almost all living organisms use Aerobic Cellular Respiration to break down glucose to produce ATP. Eukaryotes (animals and plants) are the main energy consumers. They use mitochondria as the instruments in energy-releasing reactions. Mitochondria â€Å"are found in particularly high numbers in muscle and other high-energy use tissues† (Elliott, 2005); in animals and plants, these usually drive glucose breakdown and energy consumption processes. 3. If oxygen is lacking, how might cells meet their energy needs through fermentation? Explain and give some examples of cells that can do this. When cells lack oxygen, traditional aerobic cellular respiration is replaced with fermentation. The latter does not require oxygen in its chemical reactions. â€Å"In fermentation pyruvic acid molecules are turned into some ‘waste’ product, and a little bit of energy is produced† (Elliott, 2005). Organisms use several different fermentation chains to replenish the lack of energy in anaerobic conditions. Lactic fermentation occurs by means of Lactobacillus acidophilus and some fungi; bacteria and yeast serve the engines of alcohol fermentation and ethanol production in organisms. 4. Both photosynthesis and aerobic cellular respiration are examples of complex metabolic pathways, consisting of many linked reactions. Briefly, explain the role of enzymes in catalyzing chemical reactions and in metabolic pathways. Enzymes are â€Å"specialized proteins that speed up chemical reactions† (Blankenship, 2002). Enzymes represent a separate class of catalysts that participate in metabolic processes and reduce the amount of energy organisms need to produce or consume energy. Enzymes are highly selective, and although they control each step of photosynthesis and cellular respiration, their activity will differ at each stage of the energy reaction process. For example, the process of cellular respiration would be incomplete, if not for the usefulness and active participation of ATP synthase (an active enzyme used to produce ATP molecules). The number and the set of enzymes which participate in metabolic processes vary, but all of them are critically important for the stability and quality of metabolic processes in all living organisms. References Blankenship, R.E. (2002). Molecular mechanisms of photosynthesis. Wiley-Blackwell. Elliott, W.H. (2005). Biochemistry and molecular biology. Oxford University Press.