Give a diagrammatic representation of citric acid cycle and discuss its role in metabolism. (UPSC 2020, 15 Marks, )

"साइट्रिक एसिड चक्र का आरेखात्मक प्रतिनिधित्व दें और चयापचय में इसकी भूमिका पर चर्चा करें।" (Give a diagrammatic representation of citric acid cycle and discuss its role in metabolism.)