Practice questions focused on the Krebs cycle (also called the TCA or tricarboxylic acid cycle). Covers key reactions, enzymes, and energy yield in cellular respiration.
Citric acid is the first stable compound formed when Acetyl-CoA combines with oxaloacetic acid in the Krebs cycle.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
Glucose does not directly enter the Krebs cycle; it is first converted into pyruvate and then Acetyl-CoA.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
Aerobic respiration occurs in both the cytoplasm (glycolysis) and mitochondria (Krebs cycle and Electron Transport Chain), not just the cytoplasm.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
Fumarase catalyzes the hydration of fumaric acid to form malic acid in the Krebs cycle.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
α-Ketoglutaric acid is an intermediate of the Krebs cycle that serves as a precursor for amino acid synthesis.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
NAD⁺ is reduced to NADH during glycolysis and the Krebs cycle, playing a crucial role in cellular respiration.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
Oxaloacetate is regenerated at the end of the Krebs cycle to continue the cycle.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
The Krebs cycle releases carbon dioxide as a byproduct of the decarboxylation reactions.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
Succinate dehydrogenase catalyzes the oxidation of succinate to fumarate, producing FADH₂.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
Oxidative phosphorylation uses a proton gradient across the inner mitochondrial membrane to generate ATP.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
Oxaloacetic acid is regenerated at the end of the Krebs cycle to continue the cycle.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
CO₂ is first released during the oxidation of pyruvate to Acetyl-CoA before entering the Krebs cycle.
Ref: NCERT Class 11 Biology Chapter 12: Respiration in Plants Krebs Cycle - TCA Cycle - Tricarboxylic Acid Cycle
