Biological Molecules Quiz 4

1) Which graph shows the effect of changes in pH on the activity of an enzyme ?

X Axis = pH

Y Axis = enzyme activity

2) The graph shows the effect of temperature on a chemical reaction which is controlled by enzymes. At which point are the most products molecule being released?

3) 10 cubic centimeter of a 1% starch suspension was incubated with 10 cubic centimeter of a 10% amylase solution for 5 minutes at 37 degrees Celsius. Samples were then treated with iodine solution and with Benedict solution. What are the expected results?

4) Potato cells contain an enzyme that breaks down hydrogen peroxide solution, releasing oxygen gas. Four experiments were carried out using the apparatus shown. The table shows the contents of test-tube X in each experiment. In which experiment was oxygen produced more rapidly?

5) A shallow dish holds Agar Jelly containing starch. Three similar wells X,Y and Z are cut in the Jelly.

Three different amylase solutions are prepared as follow,

1. amylase solution
2. boiled amylase solution
3. Amylase solution + dilute hydrochloric acid.

Each well has a different amylase solution added to it. 24 hours later, the Jelly is covered with iodine solution, which amylase solution was placed in each well?

6) The diagram shows an experiment to investigate the action of a protease on a 1.0 gram cube of raw meat. After 15 minutes at 20 degrees Celsius, 0.25 gram of protein was converted to amino acid. How much protein would be digested if the experiment was repeated at a temperature of 30 degrees Celsius?

7) The table shows the result of tests carried out on a drink.

What does the drink contain?

8) In the human body, large molecules are synthesized from small molecules, which row is correct for the small molecules required for the synthesis of glycogen, lipids, and proteins?

9) Milk produces a red precipitate when heated with Benedict solution. A purple color develops when the Biuret test is used on milk. Using these results only which nutrients does milk contain?

10) Which statements are correct for all enzyme?

1. Enzyme have an optimum pH.
2. Each enzyme can catalyze a number of different reactions.
3. Enzyme lower the activation energy needed for the reaction.
4. Enzyme catalyze only reactions that breakdown complex substances.
5. The shape of active side is permanently altered by excessive heat.
6. Enzyme work faster 35 degrees Celsius.