Bio 3201 Molecular Genetics

Friedrich Miescher

Coined the term “Nuclein” to decribe aweakly acidic, phosphorus-containing substance that he had isolated from the nuclei of white blood cells. It later became known as nucleic acid.

Phoebus Levene

Isolated two types of nucleic acid. He called them ribose nucleic acid (RNA) and deoxyribose nucleic acid (DNA)

Fredrick Griffith

Designed an experiment to study the pathogenic (disease causing) bacteria that were responsible for a pneumonia epidemic in London. He discovered that dead pathogenic bacteria somehow passed on their disease-causing properties to live, non-pathogenic bacteria. He called this the transforming principle.

Oswald Avery, Colin Macleod, and Maclyn McCarty

discovered the following: When they treated heat-killed pathogenic bacteria with a DNA destroying enzyme, transformation did still occur. When they treated heat-killed pathogenic bacteria with a DNA destroying enzyme, transformation did not occur. These results provided strong evidence for DNAs role in transformation.

Hershey and Chase

Discovered convinceing evidence that DNA, not proteins, carried genetic information by using a new technology, radioactive labelling, to show that genes are made of DNA.

Erwin Chargaff

found that the nucleotides are not present in equal amounts as levene said.

Chargaffs rule

In a DNA sample, the amount of adenine is about the same as thymine and the amount of cytosine is about the same as guanine.

Rosalind Franklin

used X-ray photography to analyze the structure of DNA. Was able to conclude that DNA has a helical stucture.

James Watson and Francis Crick

Published a two-page paper describing a double helix model. This model soon became accepted as the molecular structure of DNA.

Chromosome

A length of DNA and associated protein; condensed form of genetic material.

Gene

a functional sub-unit of DNA that directs the production of one or more polypeptides (protein molecules)

Genome

The total DNA in an organism’s cells

Replication

the process of copying DNA

Replication Origin

nucleotide sequence where DNA replication begins.

Helicase

Enzyme that bind to the DNA replication origin.

Replication Bubble

Oval-shaped unwound area

Replication Fork

Each Y-shaped end of the replication bubble.

Elongation

The process of joining nucleotides to extend a new strand of DNA.

DNA Polymerase

adds new nucleotides to the 3’ OH group of an existing nucleotide strand; dismantles the RNA primer; Proofreads base pairing.

Primase

Synthesizes an RNA primer to begin the elongation process.

Leading Strand

In replication, the strand made continuously

Lagging Strand

In replication, the strand made in segments.

Okazaki fragment

SHort nucleotide fragments of the lagging strand

DNA ligase

Joins together Okazaki fragments in the lagging strand

Termination

in DNA replication, the completion of new DNA strands and dismantling of the replication machine.

The genetic code

Redundant, continuous, universal.

Transcription

Process of producing RNA from DNA.

Translation

Process of producing a polypeptide based on an mRNA sequence

messenger RNA

RNA that carries the genetic code from DNA to protein synthesis machinery.

RNA polymerase

Main enzyme involved in formation of RNA from DNA

Codon

Set of three bases that code for an amino acid.

Transfer RNA

Works with mRNA in translation by delivering correct amino acid

Anticodon

Base triplet on tRNA complementary to mRNA codon

Ribosomal RNA

RNA associated with ribosomes

Mutation

permanent change to s cells DNA

Somatic cell mutation

Mutations that occur in body cells

germ line mutations

Mutations that occur in reproductive cells

Point mutation

substitution, insertion, or deletion of one or very few nucleotides.

Insertion

An extra nucleotide or several are inserted into the DNA sequence

Deletion

A nucleotide or several are deleted from a DNA sequence.

Frameshift Mutation

insertion or deletion that results in a change to the reading frame of a gene. A frameshift mutation causes the entire reading frame of the gene

Mis-sense mutation

Mutation that results in an altered but functional protein.

Nonsense Mutation

Results in loss of production of a protein

Chromosomal Mutations

the change in the chromosomes as a result of rearanged chromosome parts or changes in the number of individual chromosomes present in the genome.

Chromosomal Deletion

when a section of a chromosome is deleted

Chromosome Duplication

A type of mutation that involves the production of one or more copies of a gene or region of a chromosome.

Chromosome Inversion

If two breaks occur in the chromosome, sometimes the region between the breaks rotates 180 degrees before rejoining with the two end fragments.

Chromosome Translocation

a segment of one chromosome becomes attached to a different chromosome.

Mutagen

causes an increase in mutation rate in an cell

Physical mutagens

Mutagens that cause physical changes in the structure of DNA

CHemical Mutagen

Is a molecule that can enter the nucleus of a cell and induce mutations by reacting chemically with the DNA

Carcinogen

Cancer-causing agent

Epigenetics

The study of how your behaviours and environment can cause changes that affect the way your genes work.

Karyotype

An individuals set of chromosomes;often represented as a photo

Nondisjunction

failure of homologous chromosomes or sister chromatids to separate in meiosis.

DNA sequencing

process of identifying the nucleotide sequence of a DNA fragment

Genetic engineering

manipulation of genetic material to alter genes and blend plant, animal, and bacterial DNA

Recombinate DNA

a molecule of DNA that includes genetic material from different sources.

restriction enzyme

enzyme that catalyzes the cleavage of DNA at specific nucleotide sequences.

Polymerase chain reaction (PCR)

is a method widely used to rapidly make millions to billions of copies of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it to a large enough amount to study in detail.

Gel electrophoresis

tool used to separate molecules according to mass and charge.

CRISPR

a genetic engineering tool that uses a CRISPR sequence of Dna and its associated protein to edit the base pairs of a gene

DNA Microarray

tool for analysis for gene expression levels using cDNA probes

Biotechnology

Use of biological systems to create new technologies and products

Medicinal bacteria

Bacteria are used to produce antibiotics, vaccines, and medically-useful enzymes

Transgenic Animal

Animal genetically engineered to contain Dna from another organism.

Transgenic Plant

Plant genetically engineered to contain DNA from another organism

Clones

Genetically identical organisms