Bio Frq
Liuyi Bian
P2
1. The physical structure of a protein often reflects and affects its function.
(a) Describe THREE types of chemical bonds/interactions found in proteins. For each type, describe its role in determining protein structure. Different types of bonds/interactions in proteins lead to different kinds of structures. Three of the most commonly known chemical bonds in proteins include the hydrogen bond, the covalent bond, and the ionic bond. In hydrogen bonds, hydrogen interacts with oxygen, nitrogen, or fluorine to form either the alpha helix, or the beta sheet, which in turn determines its secondary, tertiary, or quaternary structure. Another type of bonds, the covalent bond, links amino acids together by sharing electrons; this bond is critical to proteins in that it determines the amino acid sequence, and the primary structure of the peptide chain. Lastly, the ionic bond, it is a charged R group that determines whether the protein structure would be tertiary, or quaternary.
(b) Discuss how the structure of a protein affects the function of TWO of the following.
• Muscle contraction
• Regulation of enzyme activity
• Cell signaling Enzymes bind to their substrates at a specific point called the active site. The regulation of enzyme activities mostly involves the inhibition of substrates, and this inhibition is divided into two types. The first type, competitive inhibitor, binds the inhibitors at the active site, blocking the substrates from entering. The second type is the noncompetitive inhibitor where the inhibitor binds to the opposite side of the active site, changing the shape of the enzyme, and stops it from being active. Cell signaling is also affected by the structure of the protein because in this activity, ligand binds specifically to receptor, causing it to catalyze reactions. If a gap junctions, for instance, is formed, then the shape of the junctions would allow for passages of regulatory ions or molecules, thus regulating the
P2
1. The physical structure of a protein often reflects and affects its function.
(a) Describe THREE types of chemical bonds/interactions found in proteins. For each type, describe its role in determining protein structure. Different types of bonds/interactions in proteins lead to different kinds of structures. Three of the most commonly known chemical bonds in proteins include the hydrogen bond, the covalent bond, and the ionic bond. In hydrogen bonds, hydrogen interacts with oxygen, nitrogen, or fluorine to form either the alpha helix, or the beta sheet, which in turn determines its secondary, tertiary, or quaternary structure. Another type of bonds, the covalent bond, links amino acids together by sharing electrons; this bond is critical to proteins in that it determines the amino acid sequence, and the primary structure of the peptide chain. Lastly, the ionic bond, it is a charged R group that determines whether the protein structure would be tertiary, or quaternary.
(b) Discuss how the structure of a protein affects the function of TWO of the following.
• Muscle contraction
• Regulation of enzyme activity
• Cell signaling Enzymes bind to their substrates at a specific point called the active site. The regulation of enzyme activities mostly involves the inhibition of substrates, and this inhibition is divided into two types. The first type, competitive inhibitor, binds the inhibitors at the active site, blocking the substrates from entering. The second type is the noncompetitive inhibitor where the inhibitor binds to the opposite side of the active site, changing the shape of the enzyme, and stops it from being active. Cell signaling is also affected by the structure of the protein because in this activity, ligand binds specifically to receptor, causing it to catalyze reactions. If a gap junctions, for instance, is formed, then the shape of the junctions would allow for passages of regulatory ions or molecules, thus regulating the