Your friend is trying to learn about how to kill bacteria. She reads the preservatives such as citric acid are added to foods because the acidic environment kills bacteria by denaturing the proteins. She thinks this sounds like a lot of scientific jargon and asks you what it means. How can you explain it in simpler terms?
A. Denaturing their proteins means that the proteins in bacteria are converted into carbohydrates.
B. The acid causes the cells to swell and burst open, also known as denaturation.
C. Denaturing means that the proteins of the bacteria lose their structure and can't function, so the bacteria die.
D. Denaturing refers to the fact that bacterial cells divide too quickly and die.

C. Denaturing means that the proteins of the bacteria lose their structure and can't function, so the bacteria die.

Explanation:

Denaturing is a term used to describe the loss or change of the structural shape and form of protein as a result of external influences such as heat, inorganic salts, exposure to bases or acids, and polarity of solvents. When protein become denatured, they lose their structure or shape, and therefore lose their functionality.  

Bacteria contain proteins, and when exposed to acidic environment, their protein becomes denatured. As a result of this, various functions ceases in the bacteria leading to death.

it also supports my hypothesis. if you rest first you can squeeze the clothespin more times. from the data i collected the average of the eight people concluded exercise makes your muscles more fatigued and less able to squeeze the clothespin compared to resting before squeezing.