15. All chemical breakdown processes in cells directly involve 1) reactions that are controlled by catalysts 2) enzymes that are stored in mitochondria 3) the production of catalysts in vacuoles 4) enzymes that have the same genetic base sequence

The correct answer is **1) reactions that are controlled by catalysts**.<br /><br />Here's why:<br /><br />* **Enzymes are catalysts:** All chemical breakdown processes (catabolism) in cells rely on enzymes. Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required for the reaction to occur.<br /><br />* **Mitochondria are not the sole location of enzymes:** While mitochondria are important for some catabolic processes (like cellular respiration), enzymes are found throughout the cell, including the cytoplasm, lysosomes, and other organelles. They are not exclusively stored in mitochondria.<br /><br />* **Vacuoles don't produce catalysts:** Vacuoles primarily store materials like water, nutrients, and waste products. They are not involved in the production of enzymes.<br /><br />* **Enzymes don't all have the same genetic sequence:** Different enzymes have different structures and functions, meaning they are coded for by different genes and thus have different genetic base sequences.<br />