170208- denature, enzyme , metabolism , substrate Essays - Chemistry

170208- denature, enzyme , metabolism , substrate Essays - Chemistry 170208- denature, enzyme , metabolism , substrate , synthesis list three food stuffs humans have used to prepare Cells at work Living cells Although different cells carry out different specialized functions, the same basic processes are carried out by cells. They must obtain nutrients, manufacture materials for growth and repair, provide energy for movement and metabolism and eliminate wastes. The activities of cells require a variety of biological molecules to be produced and assembled into new organelles or used for repair. Specific proteins called enzymes catalyze and precisely regulate these processes and other processes such as respiration that keeps cells alive. Enzymes: biological catalysts -Catalyst: Substance that change the rate of a reaction (almost always by speeding it up) -Make a reaction take place more often -Are needed in small amounts and are neither reactants nor products -Do not change the direction of a reaction or the amount of the product -Can catalyse a reaction either way - most reversible Enzymes Acts as a catalyst for chemical reaction in the body, speeding up to 1 million times Are specific - each enzyme catalyses only one type of reaction The substrate with which an enzyme catalyses only one type of reaction The substrate with which an enzyme acts has a shape that fits with enzymes active site - LOCK_AND_KEY MECHANISM 38798553467000Recent evidence INDUCED_FIT MECHANISM - interaction with substrate and enzyme, changes shape to make good fit Rate of enzyme action and temperature 0-63500pH changes in pH may not only effect the shape of an enzyme but it may also change the shape or charge properties of the substance so that either the substrate cannot bind to the active site.