IB Biology Topic D1.1 DNA Replication Revision Notes…

PCR Amplifies Tiny DNA Samples

Definition

PCR (Polymerase Chain Reaction)

A technique that amplifies DNA, creating millions of copies of a specific DNA sequence in just a few hours.

This lets scientists study tiny DNA samples from crime scenes, fossils, or other sources.

What PCR Needs

Template DNA
1. The DNA you want to copy.
Primers
1. Short DNA sequences that bind to the template and mark the starting point for copying.
Taq polymerase
1. A heat-resistant enzyme that builds new DNA strands.
Nucleotides (dNTPs)
1. The building blocks of DNA.
Thermal cycler
1. A machine that controls the temperature changes precisely.

Tip

Primers are essential because Taq polymerase cannot start building DNA without them.
They are designed to match the beginning and end of the target sequence.

The Three Steps of a PCR Cycle

PCR repeats a cycle of three steps 20 to 40 times, doubling the target DNA each time.

Denaturation (about 95°C)

PCR Amplifies Tiny DNA Samples

Definition

PCR (Polymerase Chain Reaction)

A technique that amplifies DNA, creating millions of copies of a specific DNA sequence in just a few hours.

This lets scientists study tiny DNA samples from crime scenes, fossils, or other sources.

What PCR Needs

Template DNA
1. The DNA you want to copy.
Primers
1. Short DNA sequences that bind to the template and mark the starting point for copying.
Taq polymerase
1. A heat-resistant enzyme that builds new DNA strands.
Nucleotides (dNTPs)
1. The building blocks of DNA.
Thermal cycler
1. A machine that controls the temperature changes precisely.

Tip

Primers are essential because Taq polymerase cannot start building DNA without them.
They are designed to match the beginning and end of the target sequence.

The Three Steps of a PCR Cycle

PCR repeats a cycle of three steps 20 to 40 times, doubling the target DNA each time.

Denaturation (about 95°C)

D1.1B PCR and gel electrophoresis: amplifying, separating and applying DNA

D1.1B PCR and gel electrophoresis: amplifying, separating and applying DNA

Subtopics and learning objectives

D1.1.4 Polymerase chain reaction and gel electrophoresis

PCR Amplifies Tiny DNA Samples

What PCR Needs

The Three Steps of a PCR Cycle

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PCR Amplifies Tiny DNA Samples

What PCR Needs

The Three Steps of a PCR Cycle

Unlock the rest of this chapter with a free account

A - Unity and Diversity

B - Form and Function

C - Interaction and Interdependence

D - Continuity and Change

A - Unity and Diversity

B - Form and Function

C - Interaction and Interdependence

D - Continuity and Change

D1.1B PCR and gel electrophoresis: amplifying, separating and applying DNA

D1.1B PCR and gel electrophoresis: amplifying, separating and applying DNA

Subtopics and learning objectives

D1.1.4 Polymerase chain reaction and gel electrophoresis

D1.1.5 Applications of polymerase chain reaction and gel electrophoresis

D1.1.4 Polymerase chain reaction and gel electrophoresis

PCR Amplifies Tiny DNA Samples

What PCR Needs

The Three Steps of a PCR Cycle

Unlock the rest of this chapter with a free account

PCR Amplifies Tiny DNA Samples

What PCR Needs

The Three Steps of a PCR Cycle

Unlock the rest of this chapter with a free account