BIO203H5 Chapter Notes - Chapter 9: Oxaloacetic Acid, Atp Synthase, Cell Membrane
Document Summary
1890s- hans and edward buchner added sucrose( used as preservative) to yeast extract. Instead preserving yeast extract, sucrose was broken down and fermented and formed alcohol. Fermentation and other type of cellular metabolism could be studied in vitro. Each step in glycolysis is catalyzed by different enzyme. All 10 reactions of glycolysis occur in cytosol. Atp production during glycolysis occurs by substrate- level phosphorylation. For each glucose molecule, the net yield: High level of atp inhibits a key glycolytic enzyme phosphofructokinase. High level of atp signals that cell doesn"t need to produce more atp. Feedback inhibition occurs when an enzyme in a pathway is inhibited by the product of the reaction sequence. Cells that are able to stop the reaction when atp is abundant can store glucose. As a result natural selection favors individuals with phosphofructokinase. Phosphofructokinase has 2 binding sites for atp. Atp can bind to active site or at a site that changes the enzyme"s activity regulatory site.
