Final answer:
Glycolysis occurs in the cytoplasm, while the Krebs cycle occurs in the mitochondria of eukaryotes and the cytoplasm of prokaryotes.
Step-by-step explanation:
Glycolysis occurs in the cytoplasm of prokaryotic and eukaryotic cells. It is the first step in the breakdown of glucose, producing energy, reduced electron carriers, and precursor molecules for cellular metabolism. The Krebs cycle, also known as the citric acid cycle, occurs in the mitochondria of eukaryotes and the cytoplasm of prokaryotes.