104 public questions tagged with this topic.
NADH donates electrons to the electron transport chain, playing a crucial role in llular respiration. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.
Ref: NCERT Biology Textbook for Class XI and XII (Botany section), Chapter: Morphology and Anatomy of Flowering Plants, Topic: Plant structure and tissue systems.
The Krebs cycle does generate ATP through substrate-level phosphorylation. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Biology Textbook for Class XI and XII (Botany section), Chapter: Biology - Botany portion covering relevant concept, Topic: Plant structure, physiology and applications.
Fermentation occurs in the absence of oxygen and does not involve the Electron Transport Chain. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.
Ref: NCERT Biology Textbook for Class XI and XII (Botany section), Chapter: Morphology and Anatomy of Flowering Plants, Topic: Plant structure and tissue systems.
Glucose is the primary substrate for respiration, undergoing glycolysis to produce ATP. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Biology Textbook for Class XI and XII (Botany section), Chapter: Biology - Botany portion covering relevant concept, Topic: Plant structure, physiology and applications.
ATP synthase utilizes the proton gradient created by the Electron Transport Chain to produce ATP. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.
Ref: NCERT Biology Textbook for Class XI and XII (Botany section), Chapter: Morphology and Anatomy of Flowering Plants, Topic: Plant structure and tissue systems.
Vitamin B₁ (Thiamine), as part of TPP, aids in the decarboxylation of pyruvate to acetyl-CoA.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Vitamins - Types, Coenzymes and Deficiency Diseases - Part 2
Long-chain fatty acids activated to fatty acyl-CoA by acyl-CoA synthetase on the cytosolic face of endoplasmic reticulum and outer mitochondrial membrane cannot diffuse across the inner mitochondrial membrane, so a dedicated import shuttle is essential for matrix beta-oxidation. Carnitine palmitoyltransferase I, CPT I, localized to the outer membrane with catalytic site facing cytosol, transfers the acyl group to carnitine, forming acylcarnitine plus free CoA. Acylcarnitine is then shuttled across the inner membrane by the carnitine-acylcarnitine translocase, CACT, an antiporter exchanging acylcarnitine inward for free carnitine outward. At the matrix leaflet, carnitine palmitoyltransferase II, CPT II, reverses the reaction, regenerating fatty acyl-CoA and releasing carnitine for recycling. Inside the matrix, beta-oxidation spiral removes two carbons per cycle as acetyl-CoA through acyl-CoA dehydrogenase, enoyl-CoA hydratase, hydroxyacyl-CoA dehydrogenase and thiolase reactions, producing NADH and FADH2 that donate electrons to respiratory chain. Resulting acetyl-CoA feeds citric acid cycle for ATP synthesis. Malonyl-CoA produced during fed state allosterically inhibits CPT I, preventing futile cycling between synthesis and oxidation and coordinating metabolic switching.
Ref: Berg et al., Biochemistry, 9th ed., Chapter 22: Fatty Acid Oxidation and Carnitine Shuttle.
Mitochondria are multifunctional organelles originating from endosymbiosis retaining sixteen point six kilobase circular genome encoding thirteen oxidative phosphorylation polypeptides, twenty two tRNAs, two rRNAs. Inner membrane cristae house electron transport chain complexes generating proton gradient driving F1Fo ATP synthase producing up to thirty ATP per glucose, contributing most cellular ATP under aerobic conditions. Matrix contains calcium uniporter MCU complex buffering cytosolic spikes shaping NFAT signaling and buffering, also participates in heme pathway where ALA synthase in matrix initiates five-aminolevulinate condensation from succinyl-CoA and glycine, intermediate steps cytosolic, final ferrochelatase inserting Fe2+ into protoporphyrin IX at inner membrane, critical for hemoglobin and cytochromes. Additional functions include Fe-S cluster biogenesis via ISC machinery, amino acid metabolism, thermogenesis via UCP1, apoptosis regulation. Protein folding of secretory pathway requiring disulfide formation oxidative environment occurs in ER lumen assisted by BiP PDI calnexin, not mitochondria, whose matrix is reducing containing Hsp60 Hsp10 chaperonin for imported proteins but not bulk folding of cytosolic cohort. Therefore protein folding excluded.
Ref: Friedman Annu Rev Cell Biol; mitochondria ATP Ca++ heme Fe-S apoptosis; folding in ER.
During aerobic respiration, a total of 6 CO₂ molecules are released per glucose molecule, two from pyruvate oxidation and four from the Krebs cycle.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Respiratory Quotient and Factors Affecting Respiration
The Krebs cycle takes place in the mitochondrial matrix, where Acetyl-CoA is oxidized to produce ATP, NADH, and FADH₂.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Respiratory Quotient and Factors Affecting Respiration
One molecule of ATP (or GTP) is directly synthesized per turn of the Krebs cycle through substrate-level phosphorylation.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Respiratory Quotient and Factors Affecting Respiration
Oxygen serves as the final electron acceptor in the Electron Transport Chain, forming water.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Respiratory Quotient and Factors Affecting Respiration
