Introduction Most of the energy liberated during the oxidation of carbohydrates, fatty acids, and amino acids are made available within mitochondria as reducing equivalents (—H or electrons). The NADH and FADH2 formed in glycolysis, fatty acid oxidation, and the citric acid cycle are energy-rich molecules because each contains a pair of electrons having a high […]
Electron Transport Chain -strictly aerobic (a brief review) Read More »
Under aerobic conditions regeneration of cytosolic NAD+ from cytosolic NADH is accomplished by transferring electrons across the mitochondrial membrane barrier to the electron transport chain where the electrons are transferred to oxygen. There are two different shuttle mechanisms whereby this transfer of electrons across the membrane to regenerate cytosolic NAD+ can be accomplished, the glycerol 3-phosphate shuttle and the malate-aspartate
Which of the following occurs in non-shivering thermogenesis? A) Glucose is oxidized to lactate B) Fatty acids uncouple oxidative phosphorylation C) ATP is spent on heat production D) Glycogen is excessively degraded E) Fatty acids are excessively oxidized The correct answer is C- Fatty acids uncouple oxidative phosphorylation Basic Concept The reduction of molecular oxygen
Non-shivering thermogenesis : uncoupling of oxidative phosphorylation Read More »
Q.1-Out of the following respiratory chain components indicate which one is a mobile carriers of electrons? a) Cytochrome oxidase b) NADH-Q reductase c) Ubiquinone d) Succinate dehydrogenase Q.2-Choose the incorrect statement about redox
Biological Oxidation-Multiple-choice questions- (part-1) Read More »
1. Dehydrogenases catalyze the transfer of hydrogen from one substrate to another in a coupled oxidation-reduction reaction.These dehydrogenases are specific for their substrates but often utilize common coenzymes or hydrogen carriers, e.g. NAD+. Which out of the following is not niacin ( NAD+) dependent dehydrogenase? a) Pyruvate dehydrogenase b) Glycerol-3-P dehydrogenase( Mitochondrial ) c) Glyceraldehyde-3-P
Biological oxidation and Electron Transport Chain (Mcqs) – part-2 Read More »
Q.1- Choose a site along the electron transport chain out of the following that is not coupled to ATP synthesis: a) NADH- coenzyme Q (CoQ) reductase b) Succinate-Co Q reductase c) Cytochrome bc1 reductase d) Cytochrome oxidase e) None of the above. Q.2- Choose a statement out of the following that best describes the uncouplers
Q.1- All of the following except one are NAD+ requiring enzymes – A. Acyl co A dehydrogenase B. Glyceraldehyde-3-P dehydrogenase C. Pyruvate dehydrogenase complex D. Malate dehydrogenase E. Lactate dehydrogenase Q.2- Which one of the following enzymes catalyzes substrate-level phosphorylation in the TCA cycle A. Malate dehydrogenase B. Succinate Thiokinase C. Succinate dehydrogenase D. Alpha
Electron transport chain and oxidative phosphorylation- Mcqs (set-1) Read More »
Q.1- If the mitochondria were blocked at the site of NADH oxidation and were treated with succinate as substrate, what would the P: O ratio is? A. Zero B. One less than normally produced by succinate C. Same as that normally produced by succinate D. One more than normally produced by succinate E. Higher than
Electron transport chain and oxidative phosphorylation- MCQs (Set-2) Read More »
Case Study An elderly couple was brought by ambulance to the emergency department after their daughter noticed that they were both acting “strangely.” The couple had been in good health prior to the weekend. Their daughter had gone out to spend the weekend with her friends. The couple had been snowed in at their house
Case study- CO Poisoning Read More »
An 18-year-old college student is brought to the emergency room unconscious, with a very high serum alcohol level. Alcohol metabolism can result in high NADH levels. When NADH enters the electron transport chain, which of the following is the correct order in which electron transfer occurs? a) NADH, coenzyme Q, cytochrome c, FMN, O2 b)
Electron Transport Chain – An Overview Read More »
