Question

1. fill in the following chart using what youve learned from models 1 - 3.

structure	bond(s) or interactions holding the structure together	short description	number of polypeptide chains involved
secondary			1
tertiary			1
quaternary			2 or more

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heating and changing ph levels are two ways to disrupt the shape of a protein. high temperatures or ph levels that vary from the natural environment of the protein will break hydrogen bonds, ionic bonds, disulfide bridges, and hydrophobic interactions. covalent bonds will usually remain undisturbed. this process of destroying the shape of a protein is called denaturing.

1. which of the four levels of protein structure is maintained after denaturing? explain your answer.

Explanation:

1. Primary Structure: Held together by peptide bonds. It is the linear sequence of amino - acids in a polypeptide chain.
2. Secondary Structure: Stabilized by hydrogen bonds. It includes alpha - helices and beta - sheets formed by local folding of the polypeptide backbone.
3. Tertiary Structure: Stabilized by various interactions such as disulfide bridges (covalent), hydrogen bonds, ionic bonds, and hydrophobic interactions. It is the three - dimensional shape of a single polypeptide chain.
4. Quaternary Structure: Held together by the same types of non - covalent interactions as tertiary structure (hydrogen bonds, ionic bonds, hydrophobic interactions) and sometimes disulfide bridges. It is the association of multiple polypeptide chains into a multi - subunit complex.

For denaturation, high temperatures or extreme pH disrupt hydrogen bonds, ionic bonds, disulfide bridges, and hydrophobic interactions. Covalent peptide bonds in the primary structure are usually not broken during denaturation. So the primary structure is maintained after denaturing.

Answer:

Structure	Bond(s) or interactions holding the structure together	Short description	Number of polypeptide chains involved
Secondary	Hydrogen bonds	Local folding (alpha - helices, beta - sheets) of polypeptide backbone	1
Tertiary	Disulfide bridges, hydrogen bonds, ionic bonds, hydrophobic interactions	Three - dimensional shape of a single polypeptide	1
Quaternary	Hydrogen bonds, ionic bonds, hydrophobic interactions, sometimes disulfide bridges	Association of multiple polypeptide chains	2 or more

1. The primary level of protein structure is maintained after denaturing. Explanation: Denaturation disrupts non - covalent bonds (hydrogen bonds, ionic bonds, hydrophobic interactions) and sometimes disulfide bridges, but peptide bonds in the primary structure remain intact.