MYTUTOR SUBJECT ANSWERS

78 views

Explain the Polymerase Chain Reaction

1. DNA must be extracted from cells using detergent. The detergent breaks downt the cells releasing the DNA.

2. Add DNA polymerase, DNA primers, and free nucleotides to DNA in a test tube. These components will be used in the PCR process to create new strands of DNA.

3. Put this into a PCR machine where the environment for the reaction can be controlled.

4. Heat to 95 degrees. At this temperature the DNA will denature, splitting the double standed DNA by breaking thy hydrogen bonds holding the bases together. This results in two separate strands with exposed bases.

5. Lower the temperature to 55 degrees. At this temperature teh DNA primers will attach to their complementary sequences of bases. This is called annealing. The primers signal the start of the target sequence you want to replicate. This either is the start of the STR (Short Tandem Repeats) sequence, or a longer sequence that contains the STR sequence.

6. Increase the temperature to 70 degrees. At this point the DNA polymerase will atach to the target sequence and begin forming a new strand of DNA by creating phosphodiester bonds between the free nucleotides that have been paired with the original strand of DNA. This process is called extension.

This process is continued for a long time until there are millions of replications of DNA that can be used for a DNA profile or any other uses.

If STR specific primers are used then the STR sequence would hvae been replicated already. If this isnt the case, then restriction enzymes will be used to "cut out" the STR sequence from the replicated DNA.

Zoe B. GCSE Psychology tutor, A Level Psychology tutor, GCSE Biology ...

2 months ago

Answered by Zoe, an A Level Biology tutor with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist

129 SUBJECT SPECIALISTS

£24 /hr

Roslyn I.

Degree: Anthropology with International Relations (Bachelors) - Exeter University

Subjects offered: Biology, Extended Project Qualification+ 2 more

Biology
Extended Project Qualification
English
-Personal Statements-

“My name is Roslyn Irving and I am currently studying for a degree in Anthropology and International Relations. Having taken Science A-levels as well as English I am in a good position to ”

£20 /hr

Catherine T.

Degree: BSc Medical Sciences with Professional Training Year (Bachelors) - Exeter University

Subjects offered: Biology, Science+ 3 more

Biology
Science
Human Biology
Extended Project Qualification
English Literature

“Aims and methods: I focus on breaking things down in to easy to digest pieces of information and will use a variety of methods to look at an aspect of your course. I will aim to make things clear and easy to remember, whilst also hopi...”

MyTutor guarantee

£20 /hr

Nooria I.

Degree: Medicine (MBBS) (Other) - Nottingham University

Subjects offered: Biology, Physics+ 5 more

Biology
Physics
Maths
Chemistry
.UKCAT.
-Personal Statements-
-Medical School Preparation-

“ABOUT ME  Hello! My name is Nooria, and I'm a fourth year medical student at University of Nottingham. I have always had a passion for learning and science, but what I really value is getting other students to love learning for the sa...”

MyTutor guarantee

About the author

£20 /hr

Zoe B.

Degree: Bsc Psychology (Bachelors) - Exeter University

Subjects offered: Biology, Psychology

Biology
Psychology

“Who am I? Hi there, my name is Zoe. I am currently in my first year at the University of Exeter studying Psychology. I have for a long time had a great interest and passion for Psychology and love to read into different areas. Somethi...”

You may also like...

Posts by Zoe

Explain the biological basis of Depression.

Explain the Polymerase Chain Reaction

Other A Level Biology questions

What is the differences between respiration and breathing?

how is urine produced in the kidney?

Describe how the structure of an antibody is related to its function?

Why is ATP used as an energy store in cells?

View A Level Biology tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok