Lab 3: Poly and Alu

Polymorphism

The occurrence of two or more distinct forms of a particular trait or genetic sequence within a population.

Alu polymorphism

Caused by retrotransposition ('jumping gene'). Can be problematic if inserted in gene, and thought to have some influence on gene expression. Helpful in tracking evolutionary changes.

Conservative Replication

One double helix is entirely old, one is entirely new.

Semi-conservative Replication

Each double helix has one old strand and one new strand.

Dispersive Replication

All strands are made up of a mix of old and new material.

Meselson–Stahl experiment

Cells start with dense nucleotides, replicate with light nucleotides. Results support semiconservative replication.

Polymerase Chain Reaction (PCR)

Can create millions of copies of a DNA sequence from as little as a single strand of DNA.

Denaturation (in PCR)

The step where high heat causes double-stranded DNA (dsDNA) to break down to single- stranded DNA (ssDNA).

Annealing (in PCR)

The step where the primer binds (or anneals) to the complementary sequence on the ssDNA.

Elongation (in PCR)

Where DNA polymerase begins to synthesize new strands of DNA from 5’ to 3’.

Thermus aquaticus

A thermophilic bacterium that evolved a polymerase that is stable and functional at high temperatures; Taq polymerase was discovered here

phosphodiester bonds

Connect the nucleotides of the new strand of DNA; link the 3’ hydroxyl of a previous nucleotide to the 5’ phosphate group of the new nucleotide with a phosphate molecule

2^n * initial number of DNA

what is the formula to determine how much DNA is produced?

primers, DNA polymerase, nucleotides, and a buffer solution

after a DNA sample is obtained you add:

hydrogen bonds

that hold the two strands of DNA together by forming between complementary base pairs.

significantly lower than denaturation

the temperature for this the annealing process is:

denaturation, elongation, annealing

rate the of temperature highest to lowest PCR: