BIO MIDTERM LECTURE STUDY GUIDE - Chapter 6 1 What is metabolism The metabolism of a cell is the sum of all its chemical reactions These reactions break

# BIO MIDTERM LECTURE STUDY GUIDE - Chapter 6 1 What is...

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Chapter 61. What is metabolism? The metabolism of a cell is the sum of all its chemical reactions. These reactions break down C6H12O6 into CO2 and H2O, and are linked sequences called METABOLIC PATHWAYS. 2. What is energy? Energy is the capacity to do work. Work is the transfer of energy to an object that causes the object to move. 3. What are the different types of energy? Potential energy: stored energy. → (includes chemical energy also): energy stored in. Kinetic energy: the energy of movement. → (includes radiant energy): waves of light, x-rays, and other forms of electromagneticradiation. → (heat or thermal energy): the motion of molecules or atoms→ (electrical energy): the flow of charged particles. *kinetic energy can be transformed to potential energy and VISE VERSA* 4. How is energy measured?5. How and from where does energy flow to organisms and to the environment?6. What are the laws of thermodynamics? FIRST LAW: energy can be either created nor destroyed by ordinary processes. (nuclear reactions): in which matter is converted into energy. *only exception* → law of conservation energy: an isolated system is a theoretical concept, but for practical purposes, you can visualize energy transformations occurring in an enormous, perfectly sealed and insulated chamber. SECOND LAW: when energy is converted from one form to another, the amount of useful energy decreases. 7. What is entropy? Entropy is the tendency toward the loss of complexity, orderliness, and useful energy. 8. You should be able to compare 2 molecules and determine which has the most entropy.S(gas) >> S(liquid) > S(solid) 9. What are exergonic and endergonic reactions? 10. Give examples of each. Exergonic reactions: the reactant molecules have more energy than do the product molecules, so the overall reaction releases energy. Can occur spontaneouslyExample: cellular respiration, this reaction release energy which is used for cell activities.(HIGHER ENERGY STATE to LOWER ENERGY STATE)Endergonic reactions: the reactants have less energy than do the products, so the reaction requires a net input in energy. Example: photosynthesis. Photosynthesis is used by all plants to convert light energy into aform of chemical energy that can be used to fuel their life processes.11. What is ATP?the main source (nucleotide) of energy for most cellular processes.Synthesis of ATP
ADP + P→ ATP + H2Orequires energy: 7.3 kcal/moleoccurs in the cytosol by glycolysisoccurs in mitochondria by cellular respirationoccurs in chloroplasts by photosynthesis12. What is its role in cellular functions? 13. What is phosphorylation?phosphorylation of a molecule is the attachment of a phosphoryl group14. What are metabolic pathways? O Metabolic pathways are chemical reactions that occur within a cell and are linked in sequenceo A starting reactant molecule is converted with the help of an enzyme into a slightly different intermediate molecule which is modified by yet another enzyme to form a second intermediate, and so on and so on until the end product is produced.