3 is the correct answer. Let me know if you want me to explain why that is the answer.
Answer:
Catalysts lower the activation energy for reactions. The lower the activation energy for a reaction, the faster the rate. Thus enzymes speed up reactions by lowering activation energy. Many enzymes change shape when substrates bind.
Explanation:
The picture from another source is attached
Answer:
Staining
Explanation:
In order to make cells or certain features of a cell more visible under the microscope, scientists use specific stains. These stains bind to certain features in a cell, allowing better distinction. For example, iodine is a common stain used in plant cells, as it turns blue/black in the presence of starch, which is abundant in plant cells.