BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Proteins undergo both cold and heat denaturation, but often cold denaturation cannot be detected because it occurs at temperatures below water freezing. Proteins undergoing detectable cold as well as heat denaturation yield a reliable curve of protein stability.

Detailed explanation-2: -While a protein can tolerate freezing and thawing through many cycles, others can easily be denatured while freezing for the very first time. This is why it’s the researcher’s responsibility to check the quality of a protein sample after every freeze-thaw cycle.

Detailed explanation-3: -While protein stability is a function of its biophysical characteristics, including its sequence, how it folds and how much of it is exposed, it has been shown that freeze-thawing and long term storage of samples results in protein degradation.

Detailed explanation-4: -Which of the following cannot denature a protein? Explanation: Iodoacetic acid, an alkylating agent cannot denature the protein.

Detailed explanation-5: -A protein becomes denatured when its normal shape gets deformed because some of the hydrogen bonds are broken. Weak hydrogen bonds break when too much heat is applied or when they are exposed to an acid (like citric acid from lemon juice).