simple bio grade 11 question

Question

The occurrence of cell-cell interactions, such as viral cells attaching to and invading human body cells, is often determined by the carbohydrate-protein structures (glycoproteins) that are present on the surface of each cell. Glycoproteins are a unique set of molecules that combine specific carbohydrate molecules with proteins. Recently, chemist at the University of Alberta have helped characterize a glycoprotein on the parasite Trichinella spiralis, which is responsible for contamination of pork. This research led to the development of a test to detect the parasite in both hogs and humans.

This glycoprotein must have a specific shape in order to function properly. Which of the following environmental factors would not denature this protein and inhibit its function?

1. Low pH
2. High pH
3. Low temperature
4. High temperature

Answer 1

The correct answer is 3, low temperature.

Proteins, including glycoproteins, have a delicate 3D structure held together by an intricate array of bonds where one part of the protein sticks to another part. Too much acid or base? The bonds break. Too high temperature? All the excess energy shakes delicate bonds apart. Only a relatively neutral pH and a nice low temperature allows the proteins to keep their shape and function.