Explain the importance of standard reference
Standard reference is important as an indicator and guideline so that the experiment will run smoothly.
What is the function of iodine solution
Iodine function as indicator for starch. Iodine which is reddish-brown solution will turn to blue-black in the presence of starch. So we can detect the presence of starch when added it into the test tube and very useful in enzyme reaction experiment.
Explain why starch turned into blue when reacted with iodide
When starch is mixed with iodine in water, an intensely colored starch/iodine complex is formed. It seems that the iodine (in the form of I5- ions) gets stuck in the coils of beta amylose molecules (beta amylose is a soluble starch). The starch forces the iodine atoms into a linear arrangement in the central groove of the amylose coil. There is some transfer of charge between the starch and the iodine. That changes the way electrons are confined and so, changes spacing of the energy levels. The iodine/starch complex has energy level spacing that are just so for absorbing visible light that giving the complex its intense blue color.
Provide the relationship between substrate concentration and enzyme reaction
At low concentration of substrate, there is a steep increase in the rate of reaction with increasing substrate concentration. The catalytic site of the enzyme is empty, waiting for substrate to bind, for much of the time, and the rate at which product can be formed is limited by the concentration of substrate which is available. As the concentration of substrate increases, the enzyme becomes saturated with substrate. As soon as the catalytic site is empty, more substrate is available to bind and undergo reaction. The rate of formation of product now depends on the activity of the enzyme itself, and adding more substrate will not affect the rate of the reaction to any significant effect
What is Km
Km is a Michaelis constant. Enzymes have varying tendencies to bind their substrates (affinities). An enzyme's Km describes the substrate concentration at which half the enzyme's active sites are occupied by substrate. small Km indicates that the enzyme requires only a small amount of substrate to become saturated. Hence, the maximum velocity is reached at relatively low substrate concentrations. A large Km indicates the need for high substrate concentrations to achieve maximum reaction velocity. The substrate with the lowest Km upon which the enzyme acts as a catalyst is frequently assumed to be enzyme's natural substrate, though this is not true for all enzymes.
What is Vmax
Increasing the substrate concentration indefinitely does not increase the rate of an enzyme-catalyzed reaction beyond a certain point. This point is reached when there are enough substrate molecules to completely fill (saturate) the enzyme's active sites. The maximal velocity, or Vmax, is the rate of the reaction under these conditions. Vmax reflects how fast the enzyme can catalyze the reaction.
Conclude the effect of temperature on the production using amylase
As the reaction temperature of amylase and starch solution increase, the rate of reaction of amylase and starch will increase. After reaching the optimal temperature of amylase, the rate of reaction of amylase and starch will rapidly decrease. Most enzymes are very specific for a certain substrate, the active site on the enzyme molecule forms a "keyhole" into which the substrate fits like a key, the substrate molecule is then broken up into many smaller pieces. The higher reaction temperature, the more kinetic energy the substrate molecules will have. It means that the molecules can move faster and have a greater chance to collide and react. However, if the reaction temperature is too high, enzyme may become denatured.