2.5 - Enzymes Flashcards
How are enzymes used in the production of lactose free milk?
- Lactose is a disaccharide and can not be absorbed by the gut
- Many adults are intolerant of the lactose in milk, as we get older the gene that produces lactase switches off
- lactose gets fermented by bacteria in the large intestine resulting in nausea, abdominal pain, and dioreahha
- milk is treated with lactase which breaks lactose into monosaccharides glucose and galactose which are easily absorbed by the gut
- lactase is obtained from the fungus kluyveromyces lactic
Uses of lactose free milk
- increase sweetness of milk, (glucose and galactose)
- reduces crystallisation of ice creams
- shortens the production time for yoghurt or cheese
Common uses of enzymes in industry
- detergents contain proteases and lipases to help breakdown protein and fat stains
- enzymes are used to break down the starch in grains into biofuels that can be combusted
- in the textile industry enzymes help in the processing of fibers, eg polishing cloth to make it look shinier
- in the brewing industry enzymes help a number of processes including the clarification of beer.
- paper production uses enzymes to help in the pulping of wood.
How can enzymes be immobilized
- aggregations of enzymes bonded together
- attached to surfaces liek glass
- entrapped in gels, eg algenate gel beads
What is an enzyme
A globular protien that increases the rate of a biochemical reaction by lowering the activation energy threshold. (i.e a biological catalyst)
What do enzymes do
- lower the activation energy of a reaction by stressing the bonds in a substrate,
define active site
region on the surface of an enzyme to which substrates bind and which catalyses the reaction
Examples of enzymes
pepsin: found in stomach and digests proteins
amalyse: breaks down starch
explain how the enzyme substrates complex attracts eachother
polar regions of amino acids attract substrate and active site of the enzyme
what do substrates do to an enzyme
induce a conformational change to the active site
collision
coming together of substrate molecule and active site
most enzyme reaction occur when-
substrates are dissolved in water
-all molecules in water are in random motion
what is denaturation
changing the structure of a protein (enzyme) so that it can not carry out its function
irreversibly alters the 3d structure of the active site
what causes denaturation
High temperatures cause denaturation as the extra energy leads to increased vibration, breaking intra-molecular bonds.
Changes in Ph cause denaturation as hydrogen bonds between amino acids in the structure of the enzyme are broken
how do low temperatures affect reactions
low temperatures result in insufficient thermal energy for the activation of a given enzyme-catalysed reaction to be achieved.
how will increasing temp below optimal temp affect rate of reaction
increasing the temperature will increase the speed and motion of both enzyme and substrate resulting in higher enzyme activity. This is because a higher kinetic energy will result in more frequent collisions between enzyme and substrate.
outline the effect of substrate concentration of enzyme activity
- increasing substrate concentration increases the rate of reaction
- at the optimum concentration of substrate molecules all active sites are full and working at maximum efficiency. Any concentration more than optimum will have no added affect.
Advantages of enzyme immobilization
C - concentration of substrate can be increased since the enzyme is not dissolved (increased rate of reaction)
R - Recycled enzymes can be used many times
S - Seperation of products is straightforward
S - stability of enzyme in temprature and pH is inreased, reducing rate of degradation