The protein structure that stays intact on heating or denaturation (primary)

The same question, asked 3 times: 29 Jun 2022, 25 Jul 2022, 27 Jan 2024. Every wording below, oldest first.

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Question 1
29 Jun 2022
138 $The structure of protein that is unaffected by heating is:$
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Question 2
25 Jul 2022
48 $During the denaturation of proteins, which of these structures will remain intact?$
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Question 3
27 Jan 2024
137 $Which structure of protein remains intact after coagulation of egg white on boiling?$
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