Enzymes
by : Julia Widmer
Enzymes - Introduction
Enzymes are biological catalyst that speed up a reaction without changing the product of the reaction. These enzymes have an active site which is a pocket in the enzyme that binds to a substrate. A substrate is a a substance that recognizes and fits into a binding site. All binding sites are different to allow certain reactions to occur, and not others, with different substrates.
In order for enzymes to be fore efficient in working in our cells, researchers have introduced a induced - fit hypothesis. The induced-fit model is a hypothesis of how enzymes change their shape to better accommodate a substrate.
enzyme
How are Enzymes are Biologically Controlled in your Cells?
1. Enzymes are controlled in our cells be the concentration of substrates and of enzymes. The amount of enzymes available for a reaction will control how often it happens. If there is a high concentration of substrates and enzymes are present the reaction rate will occur. The rate of reactions will occur until it hits the saturation level. This is a point at which increasing the substrate concentration will not be more effective and the rate will level off.
2. Enzymes are controlled by inhibitors in these three ways:
1. Competitive Inhibitors: when a competitor substance binds to a substrate binding site on an enzyme and therefore blocks a substrate from attaching to the binding site and react.
2.Non-competitive Inhibitors: when molecule binds to a site on enzyme (that is not the active site) and blocks the enzyme activity by allowing no other substrate to react with in
3. Allosteric regulation: when molecule binds to a site on enzyme (that is not the active site) and blocks the enzyme activity by altering the enzyme shape, thus changing the shape of the active site. With the active site changed no substrate can react with the enzyme
Allosteric regulation: active site shape is changed
Competitive inhibitor
Non-competitive inhibitor
What Factors effect Enzyme Activity?
Two main factors on enzyme activity are pH and Temperature.
pH
Enzymes have an optimal pH where it works the most efficiency. As it moves away from this optimal pH the efficiency of the catalyst will go down. This because when it is outside of its preferred pH, the conditions have effects on the structure and function of the actives sites on the enzyme, thus causing its activity to go down.
Temperature
Temperature has effects on enzymes as they do on chemical reactions. As temperature rises it has an effect on enzymes. As the temperature rises, the amino acid chains of an enzyme start to move and increase in motion. The enzymes work the most efficient at a temperature of 0 - 40 degrees Celsius. Anything above 50 degrees causes so much motion they begin to denature and break, therefore it cannot function.
How are Enzymes Important in Our Daily Life?
Where do we see enzymes at work in our daily life?
There are many ways enzymes affect us. In fact, without enzymes we wouldn't eat some other the thing we do today. Enzymes are a factor in cheese making in the removal or making of lactose in milk. Enzymes also have a big role in alcohol. For beer they cause it to quickly remove carbs in light beer, and for wine and juice the enzymes degrade pectin (protein) and increase the yield. Finally they play a role in the production of glucose,detrose, fructorse, and soft drink production
Not only do enzyme aid in human food, but also in animal feed too! With enzymes they degrade the components of the feed for good nutritional digestion and the use of the feed.
Going outside of the food world, enzymes also help in the breaking down of starch and stains as a component of power and liquid detergent.
Need Additional Explanation?
Check out this video on Enzymes by Paul Andersen: