DNA Analysis and Sequencing

Flashcards about DNA Analysis, Mutations, Restriction Enzymes, Gel Electrophoresis, Molecular Cloning, and Sanger Sequencing.

Central Dogma

The central dogma explains how DNA carries genetic information and how gene expression occurs, with orientation defined by 5' and 3' ends in DNA and mRNA, and N-terminus and C-terminus in proteins.

Frameshift Mutations

Mutations caused by insertions or deletions of bases that are NOT multiples of three, leading to a shift in the reading frame and altered protein sequence.

Silent Mutations

Mutations that change a single base pair but do NOT alter the amino acid sequence due to the wobble principle.

Missense Mutations

Mutations that change a single base pair and DO cause a change in the amino acid sequence. These can be conservative (similar properties) or nonconservative (different properties).

Nonsense Mutations

Mutations that change an amino acid coding triplet into a stop codon, leading to a truncated protein.

Mutations Outside of the Coding Region

Changes in the promoter sequence that alter the affinity of RNA polymerase, mutations in splicing sites that affect mRNA splicing, mutations in the AAUAAA sequence in the 3' UTR that affect mRNA stability, and mutations in the Shine-Dalgarno sequence (bacteria) that affect translation initiation.

Chromosome Arms

The two regions (arms) separated by the centromere on a chromosome in a karyotype.

Restriction Enzymes

Enzymes used by bacteria to attack the genomes of bacteriophages by cutting foreign DNA at specific sequences.

Blunt Ends

Restriction fragments with ends created by cutting the two strands of DNA at phosphodiester bonds between the same base pairs.

Sticky Ends

Restriction fragments with ends created by offset cuts, resulting in either 5' or 3' overhangs capable of base-pairing with complementary overhangs.

Gel Electrophoresis

A technique that separates DNA fragments by size using an electric field. Smaller fragments travel faster through the gel.

Plasmid

A genetic structure in a cell that can replicate independently, often used in the laboratory manipulation of genes. Simplest forms contain a polylinker, origin of replication, and selectable marker.

Selectable Marker

Gene carried on a vector that allows the selection of cells that contain recombinant DNA molecules.

Multiple Cloning Site (MCS)

A region within a cloning vector that contains several unique restriction sites.

Molecular Cloning

Isolation of large amounts of a given DNA fragment by joining it with a vector DNA, allowing propagation of the resulting recombinant DNA molecule.

Genomic Library

A long-lived collection of cellular clones that contains copies of every sequence in the whole genome inserted into a vector.

Transformation

Process in which a cell or bacterium takes up foreign DNA

Sanger Sequencing

Method that uses DNA polymerase to determine the order of bases in DNA using dideoxyribonucleotides, which cause chain termination.

Dideoxyribonucleotides

Modified sugars that lack a 3'-OH group, causing chain termination during DNA synthesis.