Question

where is pyruvate dehydrogenase located?
in the cytosol of both prokaryotes and eukaryotes
in the mitochondrial matrix of eukaryotes but not in prokaryotes
in the cytosol of prokaryotes and the intermembrane space in eukaryotes
in the cytosol of prokaryotes and the mitochondrial matrix of eukaryotes
i dont know yet

Explanation:

• Prokaryotes lack mitochondria. Their metabolic enzymes, including those related to pyruvate dehydrogenase (involved in processes like pyruvate decarboxylation which is part of cellular respiration pathways), are located in the cytosol.
• Eukaryotes have mitochondria. Pyruvate dehydrogenase in eukaryotes is located in the mitochondrial matrix as it participates in the link reaction (pyruvate to acetyl - CoA) which occurs in the mitochondrial matrix as a precursor step to the citric acid cycle (also in the mitochondrial matrix).

Answer:

In the cytosol of prokaryotes and the mitochondrial matrix of eukaryotes.