AP BIOLOGY

Detailed explanation-1: -inner membrane is called the matrix in mitochondria and the stroma in chloroplasts. Both spaces are filled with a fluid containing a rich mixture of metabolic products, enzymes, and ions.

Detailed explanation-2: -The intermembrane space (IMS) of mitochondria is enclosed by the outer and the inner membrane of the organelle. Since both mitochondrial membranes are only a few nanometers apart, the IMS is a rather tiny compartment of the cell.

Detailed explanation-3: -The mitochondrial matrix is the site of the tricarboxylic acid (TCA) cycle, a series of enzymatic reactions initiated by the conversion of pyruvate and fatty acids to acetyl coenzyme A (acetyl-CoA). Pyruvate and fatty acids are transported into mitochondria from the cytoplasm by membrane-bound permeases.

Detailed explanation-4: -The inner membrane forms numerous folds (cristae), which extend into the interior (or matrix) of the organelle. Each of these components plays distinct functional roles, with the matrix and inner membrane representing the major working compartments of mitochondria.

Detailed explanation-5: -The word “matrix” stems from the fact that this space is viscous, compared to the relatively aqueous cytoplasm. The mitochondrial matrix contains the mitochondrial DNA, ribosomes, soluble enzymes, small organic molecules, nucleotide cofactors, and inorganic ions.