Biology · Respiration in Plants · NEET
Glycolysis itself happens in the cytoplasm and does not need oxygen, so it is common to both aerobic and anaerobic respiration. But in aerobic respiration, the pyruvate made by glycolysis enters the mitochondrion to be fully broken down. So glycolysis is the first, shared stage; the aerobic-only part (link reaction, Krebs cycle, ETS) comes after and needs the mitochondrion.
Glycolysis is in the cytoplasm. The link reaction (pyruvate to acetyl CoA) and the Krebs cycle happen in the mitochondrial matrix. The electron transport system (ETS) sits on the inner mitochondrial membrane. So most of aerobic respiration is inside the mitochondrion. NEET often asks you to match each step to its exact location.
Because it is the main site where energy from glucose is released and stored as ATP. The Krebs cycle (matrix) and the ETS with oxidative phosphorylation (inner membrane) together make most of the cell's ATP. Cells that need more energy simply have more mitochondria.
Breathing (or gaseous exchange) is only the physical exchange of O2 and CO2 with the outside. Aerobic respiration is a chemical process inside cells that uses that O2 to break glucose and make ATP. Plants have no lungs, but their cells still do aerobic respiration in mitochondria; O2 reaches them by diffusion through stomata and lenticels.
One glucose molecule is fully oxidised to 6 CO2 and 6 H2O, releasing 36 to 38 ATP (the textbook value uses eukaryotic assumptions). Compare this with anaerobic respiration/fermentation, which gives only about 2 ATP because glucose is not fully broken down.
Match List I with List II: List I A. Citric acid cycle B. Glycolysis C. Electron transport system D. Proton gradient List II I. Cytoplasm II. Mitochondrial matrix III. Intermembrane space of mitochondria IV. Inner mitochondrial membrane Choose the correct answer from the options given below:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Yes. Plant cells have mitochondria and do aerobic respiration just like animal cells. They get O2 by diffusion through stomata and lenticels, not through lungs.
About 36 to 38 ATP per glucose molecule in eukaryotes, which is far more than the roughly 2 ATP of fermentation.
Oxygen is the final electron acceptor in the ETS on the inner mitochondrial membrane. It accepts electrons and combines with protons to form water, which keeps the whole electron flow and ATP-making going.
Glycolysis (cytoplasm), the link reaction and Krebs cycle (mitochondrial matrix), and the electron transport system with oxidative phosphorylation (inner mitochondrial membrane).
Because glucose is completely oxidised to CO2 and water, so all the energy in the C-H bonds is released step by step. In anaerobic respiration glucose is only partly broken down, so most energy stays locked in the products.
