Protein Structure and Function Mini-Test PDF

Mini-test/reports #3 Protein Structure and Function 1. Briefly explain the following terms in molecular biology. A. Primary structure The linear sequence of amino acids in a protein B. Secondary structure Local folded structures that form...

Mini-test/reports #3 Protein Structure and Function 1. Briefly explain the following terms in molecular biology. A. Primary structure The linear sequence of amino acids in a protein B. Secondary structure Local folded structures that form within a polypeptide due to interactions between atoms in the backbone, such as alpha-helix and beta-sheet C. Tertiary structure Three-dimensional shape of a single protein molecule D. Quaternary structure Structure formed by the assembly of multiple polypeptide chains (subunits) into a larger functional protein complex 2. Figure 1 shows the relationship between substrate concentration and the rate of reaction when the enzyme converts a substrate into a product. Explain the difference in the relationship between substrate concentration and rate of reaction when the substrate concentration is in the range A or B, and explain why the relationships in A and B are as they are. Figure 1. The relationship between the substrate concentration and rate of reaction  In range A, the relationship between substrate concentration and the rate of reaction is almost linear. This indicates that the enzyme activity increases with substrate concentration. In this range, there are more available active sites on the enzyme than substrate molecules, so the rate of reaction increases proportionally with substrate concentration. In range B, the curve plateaus, approaching Vmax, which is the maximum rate of reaction. Here, nearly all the active sites of the enzyme are occupied by substrate molecules. Increasing substrate concentration further does not significantly increase the rate of reaction because the enzymes have become saturated; there are no free active sites for additional substrate molecules to occupy and be converted to product. 3. Briefly explain about allosteric regulation. Allosteric regulation involves the regulation of a protein's function through the binding of a molecule at a site other than the protein's active site, known as the allosteric site. This binding causes a conformational change in the protein that can either inhibit or activate its activity. It's a key mechanism for controlling metabolic pathways, allowing for fine-tuned regulation of enzyme activity in response to changing cellular conditions. https://www.khanacademy.org/science/ap-biology/cellular-energetics/environmental-impacts-on- enzyme-function/a/enzyme-regulation