Bio U2 - 2.5 Flashcards
State the relationship between enzyme substrate and enzyme product.
E + S -> ES -> EP -> E + P
Explain the relationship between enzyme structure and enzyme specificity, including the role of the active site.
The enzyme structure makes it specific to only one type of substrate. While, each enzyme has a specific structure, they all have active sites which is where the catalytic reaction takes places. All enzymes are globular proteins.
Outline the three stages of enzyme activity.
- The enzyme and the substrates are in continual random motion, and the substrates will eventually collide with the enzyme’s active site
- The substrate binds to the active site. The enzyme slightly modifies its shape accordingly. The enzyme catalyzes the substrate and it changes into the products
- The products leave the active site and the enzyme remains unchanged and ready to be reused
Describe the induced fit model of enzyme action.
When the substrate enters the enzyme, it slightly changes the 3D shape of the enzyme so it can fit better (induced fit). As they fit tightly together, this induces the weakening of the bonds within the substrate, thus reducing or lowering the Activation Energy needed for a reaction to take place
Explain how temperature affects the rate of enzyme activity.
As temperature increases so does the kinetic energy of the system and this makes the
Draw a graph of depicting the effect of temperature on the rate of enzyme activity.
Notebook! (a exponential function that exponentially increases then drastically drops because the enzymes become denatured at a high temperatures)
Explain how pH affects the rate of enzyme activity.
In different parts of the body there are different phs and with this different enzymes work more optimally. For example, Pepsin needs an acidic pH and this can be found in the stomach. Trypsin on the other hand needs a basic pH that is found only in the intestine.
Draw a graph of depicting the effect of pH on the rate of enzyme activity.
Notebook! (two bell curves, one in acidic pH and one in basic pH. This shows that enzymes prefer specific pHs to be more effective)
Identify the optimum temperature or pH for enzyme activity on a graph.
The X vertex (the maximum point). For humans that is our own body temperature (37 Celsius).
Explain how substrate concentration affects the rate of enzyme activity.
When the substrate concentration is low, there are more enzyme molecules available than substrate, but as it increases it beings to level off at a max. An asymptote for a log graph.
Draw a graph of depicting the effect of substrate concentration on the rate of enzyme activity.
Notebook! (log graph as there is a point where there is a saturation of substrate and the enzymes are already catalyzing at max efficiency.
State the effect of denaturation on enzyme structure and function.
The tertiary and secondary bonds begin to break and the enzymes lose their structure and function, as there is no longer a functional active site.
List industries that use commercially useful enzymes.
Detergents => Enzymes hydrolyze molecules, which breaks stains apart (Protease and Amylase)
Textiles => Denim washing, silk polishing, and softening of leather (Protease and Cellulase)
Food Processing => Enzymes are used in baking, brewing, and fruit juice processing (Amylase, Pectinase, and Lactase)
Pulp and Paper => whitens paper, removes stickiness, and soften pulp to form paper (Xylanase and Cellulase)
Explain how and why industrial enzymes are often immobilized
Enzymes are physically attached to a surface (be it through polymer/gel entrapment, surface adsorption, covalent binding, and or Electrostatic bonding. This way, the substrate only passes through them and don’t completely wash out the product and create unnecessary waste.
State the source of the lactase enzyme used in food processing.
Lactase is commonly obtained from yeast and sometimes bacteria. Source is from a fungus: Aspergillus niger
