Question

In aerobic respiration the Krebs cycle occurs inside the
A. Chloroplast
B. Cytoplasm
C. Mitochondria
D. Ribosome

Answer 1

Hint:
-Krebs cycle, also known as citric acid cycle or TCA cycle, is a series of chemical reactions that takes place in all aerobic organisms.
-In this process, the stored energy is released by the oxidation of acetyl-CoA, derived from carbohydrates, fats and protein.
-In this cycle, the conversion of succinyl-CoA to succinate is the only step that produces ATP directly.

Complete step by step answer:
-Adenosine triphosphate, guanosine triphosphate, pyruvate dehydrogenase, coenzyme Q and coenzyme A (CoA) are required in the process of Krebs cycle. GTP, NADH, FADH2 and CO2 are products of Krebs cycle.
-The mitochondrial matrix is a dense solution which surrounds the mitochondria crests. This matrix contains different enzymes and coenzymes.
-The Krebs cycle takes place in the mitochondria because all the enzymes, coenzymes and phosphates, except succinate dehydrogenase, required for the various biochemical reactions of the cycle are contained in the mitochondrial matrix.
-Before entering into the Krebs cycle, the electrons pass from succinate by the help of FAD and iron-sulfur centers.
-In the mitochondrial matrix, the reactions of the krebs cycle add electrons and protons to a number of electron carriers which are a part of the electron transport chain to produce ATP. This ATP is then used in cells to power various cellular reactions that occur in cells.
-Krebs cycle is not connected to the chloroplast, cytoplasm or ribosome.


Note: This process is known as a cycle even though it follows only one specific route. Around three different segments of the Krebs cycle have been recognized. Succinate dehydrogenase, integral membrane protein locked to the inner mitochondrial membrane is also required for Krebs cycle.