Cell Energy Worksheet - Cellular respiration

Associate Program Material

Cell Energy Worksheet

Answer the following questions:

Cellular respiration:

• What is cellular respiration and what are its three stages? Cellular respiration is the set of the metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. The reactions involved in respiration are catabolic reactions that involve the redox reaction (oxidation of one molecule and the reduction of another. Respiration is one of the key ways a cell gains useful energy to fuel cellular changes. The three stages of memory are sensory (immediate), short-term, and long-term memory.

• What is the role of glycolysis? Include the reactants and the products. Where does it occur? They are used to raise the energy content of the reactants in the first and third steps of glycolysis (glucose-6-phosphate and fructose-1,6-diphosphate). Chemical reactions proceed more "easily" when they go from a high-energy state to a lower-energy state. Another way of saying it that they become "more reactive," since the ATPs are supplying the activation energy for the reactions.

• What is the role of the citric acid cycle? Include the reactants and the products. Where does it occur? They both are the same. It does not matter which one you pick. Both represent the same substance, citric acid. The only difference is that for H3C6H5O7, the H's are separated. If you simplify the equation by adding up the H's, then your answer will be C6H8O7. Light reactions take place on the thykaloid membranes of the chloroplast. Light reaction requires light and water, and produces ATP and Oxygen. Dark reactions take place in the stroma (fluid that fills the chloroplast. It uses the ATP produced in light reactions to make glucose.

• What is the role of the electron transport system? Include the reactants and the products. Where does it occur? The ETC has two functions that are coupled together....It allows respiration with concomitant ATP production oxidative phosphorylation . Metabolic poisons like cyanide carbon monoxide sodium azide block the terminal cytochrome in the ETC and prevent respiration = death. Thyroxine a hormone from the thyroid, blocks ATP production while allowing and enhancing respiration. This selective uncoupling allows the energy that would have been "saved" as ATP to be used to warm the body of homeotherms like us in a process called thermogensis . Light reactions take place on the thykaloid membranes of the chloroplast. Light reaction requires light and water, and produces ATP and Oxygen. Dark reactions take place in the stroma (fluid that fills the chloroplast). It uses the ATP produced in light reactions to make glucose.

Photosynthesis:

• What is the overall goal of photosynthesis? Photosynthesis help the plant to make there own food. The goal of the photosynthesis is for plants to absorb energy. It is crucial for their development.

• Because photosynthesis only occurs in plants, why is it essential to animal life? According to the biophysicist Alfred Lotka's principles of thermodynamics, the energy retained by a primary producer is transferred to the herbivore that consumes it. [ Similarly, when a carnivore consumes an herbivore the energy of the herbivore, to which the primary producer contributed, is transferred to the carnivore. This process of energy transfer is called the food chain and describes the transfer of energy through an ecosystem. Because energy begins with primary producers, all organisms in an ecosystem indirectly rely on photosynthesis.

• What is the role of the light reactions? Include the reactants and the products. Where does it occur? To generate energy-carrying molcules (NADPH and ATP) from sunlight to drive the light-independent reactions. Light reactions take place on the thykaloid membranes of the chloroplast. Light reaction requires light and water, and produces ATP and Oxygen. Dark reactions take place in the stroma (fluid that fills the chloroplast). It uses the ATP produced in light reactions to make glucose.

• What is the role of the Calvin cycle? Include the reactants and the products. Where does it occur? Reactants: ATP, NADPH2, CO2, Products: Glucose, Oxygen. The Calvin (or Calvin-Benson) cycle is the cyclic pathway of metabolic reactions that occur as part of photosynthesis to create glucose and other sugars using products from the light energy (most commonly sunlight) dependent part of it. It is named after the scientists who first worked it out. The Calvin cycle is the light independent reaction of photosynthesis. This is an important detail to note because it does not compile photosynthesis. There is also a light dependent stage that requires light energy.

Summary:

• Explain how photosynthesis and cellular respiration are linked within ecosystems. Both are processes that provide energy for cells/organisms. photosynthesis provides energy for photoautotrophs through light reactions in the thylakoids and the Calvin cycle. cellular respiration gives hetertrophs the energy they need through glycolysis, the Krebs cycle, and electron transport system.

• Visit the NASA website (http://data.giss.nasa.gov/gistemp/graphs/) and research global temperature changes. How has global warming affected overall temperatures? What effects do cellular have on global respiration and photosynthesis warming? The process of Photosynthesis takes the waste product of Cellular Respiration, CO2, and uses it to make energy, while Cellular Respiration uses the waste product of Photosynthesis, O2, and uses it to make energy. This relationship is good and beneficial to both parties, until this balance is interrupted. Human action such as deforestation have caused this relationship to deteriorate. When humans cut down and destroy plants, they are destroying the avenue to get rid of CO2 gases because while plants use CO2 they can only use so much at a time and when this extent is reached this causes an excess in the Earth's atmosphere. This excess places CO2, a greenhouse gas, into the atmosphere which contributes to Global Warming. Cellular Respiration is one of the avenues which adds CO2 into the atmosphere because it gives off CO2 as a waste product. It appears that as long as the population of animals increases and deforestation occurs Global Warming is almost to become an inevitable fate of planet Earth if not dealt with properly.