2.4.2. Cofactors 0.0 / 5 ? BiologyEnzymesASOCR Created by: shyde7Created on: 19-05-16 15:52 Which enzymes in particular can only work if cofactors are attached? Enzymes used in catalysing oxidation-reduction reactions. 1 of 26 What is a prosthetic group? A cofactor that is permanently bound by covalent bonds to an enzyme molecule. 2 of 26 What is the prosthetic group of carbonic anhydrase? A zinc ion. 3 of 26 What is good about most enzyme-catalysed reactions? They are reversible (they can go in either direction) 4 of 26 What does this depend on? The concentration of substrate or product molecules. 5 of 26 Where is zinc needed in the human body? It is needed for insulin (a polypeptide hormone) to function correctly. 6 of 26 Which people may have zinc deficiencies? People whose diets do not contain much meat. 7 of 26 What can help these people have more zinc in their diets? A genetically modified crop plant (e.g. plantain - a type of banana). 8 of 26 Where is plantain useful? In places like East Africa where people may not be able to obtain much meat. 9 of 26 Why are cofactors important? They may ease the formation of enzyme-substrate complexes and therefore increase the rate of a reaction. 10 of 26 What is a co-substrate? A cofactor that binds to the substrate to give the molecule the correct shape to bind to the active site. 11 of 26 How else can cofactors help form enzyme-substrate complexes? They can change the charge distribution to make the temporary bonds easier to form. 12 of 26 What is the cofactor of amylase? Chloride ions. 13 of 26 What are coenzymes? They are like cofactors, but bind to the active site rather than the surface. 14 of 26 What happens to coenzymes during a reaction? They are chemically changed and so have to be recycled back to the cell - sometimes this is catalysed by another enzyme. 15 of 26 Where are many coenzymes derived from? Water-soluble vitamins. 16 of 26 What happens if there are vitamins missing from an individual's diet? Diseases may occur. 17 of 26 What is the coenzyme derived from vitamin B12? Cobalamin conenzymes. 18 of 26 What is the disease that may result from a deficiency of B12? Pernicious anaemia. 19 of 26 What is the coenzyme derived from folic acid? tetrahydrofolate 20 of 26 What is the disease that may result from a deficiency of folic acid? Magablastic anaemia 21 of 26 What is the coenzyme derived from Pantothenate, B6? Coenzyme A 22 of 26 What is the disease that may result from a deficiency of Pantothenate, B6? Elevated blood-plasma triglyceride levels. 23 of 26 What is the coenzyme derived from Thiamine, B1? Thiamine pyrophosphate 24 of 26 What is the disease that may result from a deficiency of Thiamine, B1? Beriberi 25 of 26 What are NAD and NADP? Hydrogen acceptors that are both derived from nucleotides. 26 of 26
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