Question 21 During an extraction of DNA from strawberries, alcohol (ethanol) is

Question

Question 21

During an extraction of DNA from strawberries, alcohol (ethanol) is used in the process. What is the function of this alcohol?

to help the DNA go into solution

to precipitate the DNA from the surrounding solution

to break the DNA strands into smaller, more manageable pieces

none of the above

4 points

Question 22

Amylase is an enzyme that is produced in our saliva to help digest starch. Suppose amylase is added to two separate test tubes containing equal amounts of starch. One tube is put in the refrigerator, while the second tube is left out on the counter. When the tubes are checked the next day, which one will have the least amount of starch in it?

the one in the refrigerator

the one on the counter

both should have the same amount of starch in them

this question cannot be answered from the amount of information given

to help the DNA go into solution

to precipitate the DNA from the surrounding solution

to break the DNA strands into smaller, more manageable pieces

none of the above

Explanation / Answer

21. (B)

Use non-iodized table salt or laboratory-grade sodium chloride. 95% ethanol or 91 or 100% isopropyl alcohol can be used to precipitate the DNA.

22. (B)

amylase requires a specific temperature in order to function properly. Temperature is an important factor in determining how an enzyme functions. When the temperature of an enzyme changes, so does the 3D structure of the enzyme. The 3D structure is crucial for the enzyme's ability to act as a catalyst. The shape of the enzyme makes the enzyme sensitive to what sub-straits it breaks and indicates where on the active site it will interact with the sub-straight. As the structure of the enzyme changes it becomes less efficient because the molecules that the enzyme normally targets (sub-straits) no longer fit into the active site and therefor the enzyme cannot interact with them as it would have normally.

Related Questions

Navigate

• Browse (All)
• Browse Q
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.