Questiohs 1. When a ate of the reaction is independent of the sub- on is perform
ID: 230132 • Letter: Q
Question
Questiohs 1. When a ate of the reaction is independent of the sub- on is performed in zero-order kinetics c. There is not enough substrate d. The amount of enzyme is too high to strate concentration substrate concentration is very low measure The rate of reaction is directly proportional to the 6. The isoenzymes LD-4 and LD-5 are elevated in substrate concentration d. The enzyme level is always high a. Liver disease b. Pulmonary embolism c. Renal disease 2. Activation energy is a. Decreased by enzymes b. The energy needed for an enzyme reaction to stop c. Increased by enzymes d. Very high in catalyzed reactions d. Myocardial infarction 7. Which CK isoenzyme is elevated in muscle diseases? a. CK-MM b. CK-BB c. CK-MB d. CK-NN 3. Enzyme reaction rates are increased by increasing tem- peratures until they reach the point of denaturation at a. 40-60°C b. 25-35°C c. 100°C d. 37°C 8. Elevation of serum amylase and lipase is commonly seen in a. Acute pancreatitis b. Acute appendicitis c. Gallbladder disease d. Acid reflux disease 4. An example of using enzymes as reagents in the clinical aboratory is a. The hexokinase glucose method b. The diacetyl monoxime blood urea nitrogen (BUN) 9. The saccharogenic method for amylase determinations measures a. The amount of product produced b. The amount of substrate consumed c. The amount of iodine present d. The amount of starch present c. The alkaline picrate creatinin d. The biuret total protein method e method Aktivity of enzymes in serum may be determined rather than concentration because amount of enzyme is too low to measure The temperature is too high (continues on page 286)Explanation / Answer
1) A zero order reaction depends only on the time. Substrate concentration has no effect on the rate of a zero order reaction and hence, (a) is the correct answer.
2) Activation energy is the energy difference between the reactant and the transition state. The higher the activation energy, the slower is the rate of the reaction. Activation energy is decreased by enzymes. Enzymes lower the energy of the transition state and hence, the energy difference between the reactant and the transition state is lower; consequently, (a) is the right answer.
3) Denaturation of an enzyme is a phenomenon where the enzyme suffers permanent damage to its overall shape and cannot function properly. Enzymes are usually denatured around 60°C; hence, (a) is the right answer.