Oxidative Phosphorylation

Q: _________________ blocks oxidative phosphorylation by inhibiting ATP-synthetase

Oligomycin. Oligomycin binds and blocks ATP synthase directly, halting oxidative phosphorylation while still permitting some proton leak. Cyanide, CO, antimycin A and amytal instead block electron transport chain complexes. ---

Q: Cancer cells exhibiting the Warburg effect produce how many ATP molecules per glucose compared to normal oxidative phosphorylation?

2 versus 36. ** Aerobic glycolysis (Warburg effect) produces only 2 ATP molecules per glucose molecule, versus 36 from mitochondrial oxidative phosphorylation. Despite being less efficient, this metabolic shift allows rapid cell division by shunting glucose carbons toward biosynthetic pathways. ---

There is a genetic mutation in one of the genes coding for enzymes in the oxidative phosphorylation pathway.

What our notes say

There is a genetic mutation in one of the genes coding for enzymes in the oxidative phosphorylation pathway. (CNS PATHOLOGY — Past Paper Questions & Answers)
Oxidative phosphorylation is made possible by the close association of the electron carriers and the protein molecules. (Medical Physiology Assorted SAQs — With Answers (Past Paper Study Guide))
When dicyclohexylcarbodiimide (DCCD) is added to a suspension of tightly coupled, actively respiring mitochondria, the rate of electron transfer (measured by oxygen consumption) and the rate of ATP production (oxidative phosphorylation) dramatically decrease. (Biochemistry Revision Questions — Electron Transport Chain & Redox (Past Paper))
*Cancer cells characteristically favor aerobic glycolysis over oxidative phosphorylation even when oxygen is available — a metabolic reprogramming that supports rapid biomass production.* (General Pathology MCQs: Cancer, Tumors & Molecular Path Review)
It yields much more energy than the oxidative phosphorylation cycle (Physio Y1 EOY 2021 — Past Paper Questions & Answers)
Select one: 1.00 a. codes for most of the enzymes of electron transfer chain and oxidative phosphorylation in the mitochondria. (Physio Y1 EOY 2021 — Past Paper Questions & Answers)

Study material on Oxidative Phosphorylation

Images

Electron micrograph of a mitochondrion (A) beside rough endoplasmic reticulum (B)

Practice questions on Oxidative Phosphorylation

_________________ blocks oxidative phosphorylation by inhibiting ATP-synthetase

Oligomycin
Carbon monoxide
Cyanide
Antimycin A
Amytal ✅ Answer: A. Oligomycin

Answer: A. Oligomycin binds and blocks ATP synthase directly, halting oxidative phosphorylation while still permitting some proton leak. Cyanide, CO, antimycin A and amytal instead block electron transport chain complexes. ---

Cancer cells exhibiting the Warburg effect produce how many ATP molecules per glucose compared to normal oxidative phosphorylation?

2 versus 36
10 versus 36
36 versus 2
Equal amounts

Answer: A. ** Aerobic glycolysis (Warburg effect) produces only 2 ATP molecules per glucose molecule, versus 36 from mitochondrial oxidative phosphorylation. Despite being less efficient, this metabolic shift allows rapid cell division by shunting glucose carbons toward biosynthetic pathways. ---

During glycolysis and subsequent oxidative phosphorylation of one molecule of glucose to synthesize ATP in the cell ---

Glycolysis alone yields half the total number of ATP's produced
The high energy compound that enters the mitochondrion after glycolysis is Lactic Acid
The main enzyme that mediates ATP synthesis in the matrix is Pyruvate Dehydrogenase
30 ATPs arise from oxidation of the 24 Hydrogen atoms generated during the early stages of glucose degradation
The total energy yield is 48 ATPs

Answer: A.