Biology Midterm 2 STUDY GUIDE Questions With Verified Answers

Biology Midterm 2 STUDY GUIDE Questions With Verified Answers A reaction has a ∆G of -5.6 kcal/mol. Which of the following would most likely be true? a)The reaction would result in products with a greater free-energy content than in the initial reactants. b)The reaction could be coupled to power an endergonic reaction with a ∆G of +8.8 kcal/mol. c) The reaction would proceed by itself but might be very slow d) To take place, the reaction would need to couple to ATP hydrolysis. e)The reaction is nonspontaneous - answerThe reaction would proceed by itself but might be very slow Why does the body use chemical energy? a) The potential energy stored in chemical bonds can be released to perform work within a cell. b) Chemical energy is the only type of energy that can be converted to kinetic energy. c) Energy stored in chemical bonds is difficult to convert to other forms of energy. d) Chemical energy produces more heat than other forms of energy when used by the body. - answerThe potential energy stored in chemical bonds can be released to perform work within a cell. Energy is stored long-term in the bonds of ___________ and used short-term to perform work from a(n) __________________ molecule. - answerglucose; ATP If entropy is always increasing in the universe, then why is it possible for living things, that are highly ordered and have low entropy, to exist? - answerLiving things are not closed systems, energy from sunlight is put into living things and makes life possible. Check all of the following statements that accurately describe the roles and characteristics of enzymes in biochemical reactions. - Enzymes increase the overall free energy change (ΔG) of reactions, thereby making them more thermodynamically favorable. - Enzymes are specific to the reactions they catalyze, meaning that each enzyme only accelerates specific reactions based on the fit between the enzyme and the substrate. - Enzymes reduce the activation energy required for a reaction to proceed, but do not alter the overall free energy change (ΔG) of the reaction. - Enzymes can change an endergonic reaction (ΔG0) into an exergonic reaction (ΔG0) by altering the reactants and products. - Enzymes are consumed in the reactions they catalyze and must be regenerated in subsequent reactions. - answer- Enzymes are specific to the reactions they catalyze, meaning that each enzyme only accelerates specific reactions based on the fit between the enzyme and the substrate. - Enzymes reduce the activation energy required for a reaction to proceed, but do not alter the overall free energy change (ΔG) of the reaction. Which type of metabolic pathway uses energy to take small molecules and assemble them into larger ones? Hydraulic Synthetic Catabolic Anabolic - answerAnabolic Which of the following are TRUE about enzymes? (Select all that apply) Change the free energy of a reaction Are used up by a reaction and can only be used once. Convert a reaction from endergonic to exergonic Change the activation energy of a reaction Catalyze chemical reactions Are proteins - answer- Change the activation energy of a reaction - Catalyze chemical reactions - Are proteins Which of the following has positive ΔG ? (select all that apply) - a reaction where the net change in free energy makes some of that energy available to do work - a reaction where the products have more free energy than the reactants - burning wood - an exergonic reaction - an endergonic reaction - answer- a reaction where the products have more free energy than the reactants - an endergonic reaction Which of the following reactions is endergonic? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O 6 CO2 + 6 H2O → C6H12O6 + 6 O2 ATP + glucose → ADP + Pi + glucose-6-phosphate ATP → ADP + Pi - answer6 CO2 + 6 H2O → C6H12O6 + 6 O2 Which of the following reactions is exergonic? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O 6 CO2 + 6 H2O → C6H12O6 + 6 O2 ATP + glucose → ADP + Pi + glucose-6-phosphate ATP → ADP + Pi - answerATP → ADP + Pi What is the name of the protein complex through which H+ ions flow and which makes ATP in the last step of oxidative phosphorylation? a) FADH2 b) ATP synthase c) acetyl coA d) mitochondrial matrix - answerATP synthase Which catabolic process evolved first and is shared by the most organisms on earth? a) Oxidative phosphorylation b) glycolysis c) pyruvate oxidation d) photosynthesis e) citric acid cycle - answerglycolysis Approximately how much ATP does a resting adult generate per day? - answer60 kilograms (about 132 pounds) After each of these steps in cellular respiration, identify the best match that tells where the energy, that was in the original glucose molecule, resides. Citric acid cycle: Glycolysis: Oxidative phosphorylation: Electron Transport Chain: - answerCitric Acid Cycle: ATP, NADH, FADH2 Glycolysis:pyruvate, ATP, NADH Oxidative phosphorylation: ATP Electron Transport chain: ATP, Proton electrochemical gradient Each phrase has a corresponding term