Ch.9+10 - Enzymes Flashcards
What is metabolism?
Metabolism is the sum of all chemical reactions that take place within an organism.
What is solar energy?
Solar energy is of the Sun, it is the primary source of energy for life on earth.
What is cellular energy?
Cellular energy is the energy stored in the bonds of biomolecules.
What is a catalyst?
A catalyst is a substance that speeds up a reaction, without itself being used up in the reaction.
What is an enzyme?
Enzymes are biological catalysts made of protein. Enzymes work because they have the 3D shape to fit a particular molecule. Enzymes act on a substrate and form products. Enzyme reactions are reversible, they may be anabolic or catabolic.
What are the roles of catabolic enzymes?
Amylase(diastase) is a catabolic enzyme that breaks down starch into maltose. It is produced in the salivary glands, the pancreas and when seeds germinate. Pepsin and lipase are also catabolic enzymes used in digestion, as are enzymes used in respiration.
What are the roles of anabolic enzymes?
DNA ligase is used in genetic engineering to join two pieces of DNA together. DNA polymerase is found in both plants and animals, it forms and repairs DNA. Rubisco controls photosynthesis, it converts water and carbon dioxide into glucose.
What is a denatured enzyme?
A denatured enzyme has lost its shape and can no longer function.
How does temperature affect enzyme activity? Draw a graph describing its effect.
At very low temperatures, ice forms, cell contents become solid and enzymes cannot work. Human enzymes work best at 37C, plant enzymes work best between 20C and 30C. Enzymes begin to lose their shape above a certain temperature. Usually, above 50C enzymes become denatured.
How does pH affect enzyme activity? Draw a graph describing its effect.
Most enzymes work well between a pH of 6 and 8. Outside this range, enzymes quickly become denatured. Pepsin, an enzyme of the stomach, works best at a pH of 2, this is to cope with the acidic conditions of the stomach.
What is bioprocessing?
Bioprocessing is the use of enzyme-controlled reactions to produce a product. Early examples of bioprocessing is the use of yeast and bacteria to produce cheese, yoghurt, wine and other food. In recent times it is used to produce a vast range of products, such as antibiotics, vaccines, vitamins and enzymes.
What is a bioreactor?
A bioreactor is a vessel in which living cells or their products are used to make a product.
What are immobilised enzymes?
Immobilised enzymes are enzymes that are attached, to each other, or to an inert material. They may be enclosed within a membrane or a gel. Adsorption means that enzymes are physically attached to inert supports such as ceramics or cellulose particles.
What are the advantages of immobilsed enzymes?
Immobilised enzymes don’t need to be separated from the product, replacing enzymes can be expensive. Immobilising enzymes increases its stability.
What are the uses of immobillised enzymes?
Glucose isomerase is used to convert glucose into fructose(saving costs). Penicillin acylase is an expensive enzyme used to alter the structure of penicillin, potentially altering or enhancing its function. Lactase is immobilised in porous beads and used to convert lactose(a sugar found in whey) into 2 sweeter tasting sugars called glucose and galactose. These products are used to replace condensed milk in the manufacture of caramel.
Describe the induced fit model with the aid of a diagram.
