Biochem Exam 3 Lecture 1 MCPHS Exam Study Guide with Complete Solutions

©SOPHIABENNETT EXAM SOLUTIONS_2024/2025 Monday, September 2, 2024 12:59 PM Page | 1 Biochem Exam 3 Lecture 1 MCPHS Exam Study Guide with Complete Solutions What is the final stage of cellular respiration and where does it happen - Answer️️ - Oxidative phosphorylation, in the mitochondria What does oxidative phosphorylation couple - Answer️️ -The oxidation of NADH or FADH2 to the reduction of O2 to get H2O and formation of ATP Where in the mitochondria are the components of the respiratory chain - Answer️️ - Inner membrane Briefly summarize the process of the respiratory chain - Answer️️ -1. Electrons flow through a chain of membrane-bound carriers 2. This results in protons (H+) pumped from matrix to inter membrane space 3. H+ gradient drives ATP synthesis Electrons are transferred from a substrate to which universal electron acceptors - Answer️️ -NAD+, NADP+, FAD, FMN NAD+ or NADP+ accepts what and releases what, how many electrons at once - Answer️️ -Accepts H- (H+ and 2 electrons), picks up a pair of electrons at once, releases a proton How many electrons can FAD or FMN accept and transfer at a time - Answer️️ -One or two electrons AT A TIME ©SOPHIABENNETT EXAM SOLUTIONS_2024/2025 Monday, September 2, 2024 12:59 PM Page | 2 What are the other sequentially acting electron carriers in the respiratory chain besides NAD and flavoproteins - Answer️️ -Hydrophobic quinone (ubiquinone, Q), Cytochrome (contain iron), Iron-sulfur proteins Describe the characteristics of ubiquinone AKA Coenzyme Q [Q] - Answer️️ -Lipid- soluble, small, freely diffusible (can move around everywhere) How many electrons can Q accept and what does it carry - Answer️️ -Accepts 1 or 2 electrons, carries a proton with each electron What is the difference between ubiquinone (Q) and ubiquinol (QH2) - Answer️️ -Q is fully oxidized so it has no electrons, QH2 is fully reduced so it has 2 more electrons and H+ than Q Cytochromes have how many classes and what distinguishes between them