Given a scientific question, generate a correct answer to it.

Input: Consider Input: To undo the tarnish on copper pennies, you can place them in what liquid?

Output: vinegar

Input: Consider Input: Giardiasis and malaria are diseases caused by what organism?

Output: protozoa

Input: Consider Input: What type of protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle?
Output: membrane protein