Ch 9 Genetics & Flow of Genetic Information

Genotype

(sum of all gene types) DNA sequences An organisms distinctive genetic makeup

Transduction

-Bacteriophage infect host cells -Serve as the carrier of DNA from a donor cell to a recipient cell

Conjugation

-Transfer of plasmid DNA from a F+ (donor) cell to a F- cell -An F+ bacterium possesses a pilus that attaches to the recipient cell and creates pore for transfer

rRNA

-Transports the DNA master code to the ribosome -Single strands of RNA transcribed from DNA templates -RNA polymerase performs the synthesis -Assembled in the 5' to 3' direction

Codons

-Triplets of nucleotides that specify aa's -Multiple codes for one amino acid -20 aa's, start codon, stop codon

Primase

Adds RNA primers

In protein synthesis of Eukaryotic cells, mRNA molecules:

Contain sequences called introns that must be removed

RNA

Contains ribose as the sugar Uracil instead of thymine The nucleic acid responsible for carrying out the hereditary program transmitted by an organisms DNA.

Transcription

DNA is read or 'transcribed' into mRNA Synthesis of RNA molecules

DNA Polymerase

DNA polymerase I -Removing primer, closing gaps, repairing mismatches DNA polymerase III -Adding bases to the new DNA chain; proofreading the chain for mistakes

Promoters

DNA sequences that bind a protein called the sigma factor *TATA box (TATAAT)

Transcription Unit

DNA that encodes RNA (and the protein) sequence

Ligase

Joins DNA molecules together

Procaryotic

Single, circular molecules

DNA structure

Sugar = 'deoxyribose' (a ribose missing an oxygen) Phosphate molecule Four types of nucleotides -A-Adenine -T-Thymine -G-Guanine -C-Cytosine

Replication

Synthesis of new DNA molecules

DNA replication

The DNA strands are each copied (replicated) just prior to cell division so each new cell will have it's own DNA double-helix.

Replication Fork

The Y-shaped point on a replicating DNA molecule where the DNA polymerase is synthesizing new strands of DNA.

Synthesis of Protein requires:

mRNA, tRNA, and ribosomes

tRNA

-Brings amino acids to ribosome during translation -Participates in translation, carries amino acids to ribosomes -Complimentary sequences form hairpin stem-loops -Amino acid attachment site and the 'anticodon'

rRNA

-Forms the major part ribosome -participates protein synthesis -consists of 2 subunits (large and small) -a subunit is composed of rRNA and protein -performs translation reaction

Transformation

-Nonspecific acceptance of free plasmid DNA by the cell -DNA can be inserted into the chromosome -Competent cells readily accept DNA at a higher frequency

Chromosome

A discrete cellular structure composed of a neatly packaged DNA molecule. (DNA + Proteins)

Sigma

Allows the RNA polymerase bind and promotes synthesis of RNA

RNA polymerase

Enzyme that performs transcription 'makes polymers of RNA'

Phenotype

Expression of the genotypes in the form of proteins.

Griffith Experiment

First experiment suggesting that bacteria are capable of transferring genetic information through a process known as transformation.

Ribosomes

Form peptide bonds

Eucaryotic

Linear, numerous, numbered

Lagging Strand

Multiple (okazaki) fragments are synthesized and ligated to form one continuous strand.

Introns

One to several intervening sequences of bases located along the gene

In cells the synthesis of new DNA molecules requires:

Primers, nucleotides, and DNA polymerase

Okazaki Fragments

Producing short fragments of DNA 5--3

Translation

RNA is read or 'translated' into amino acids (proteins) DNA--RNA--Amino Acids (proteins) Synthesis of Protein

Protein

RNA molecule

Gyrase

Rewinds (supercoils) the DNA

The Stop Codon UGA

Signals the halt to addition of new amino acids

Leading Strand Synthesis

The newly forming 3' DNA strand that is replicated in a continuous fashion without segments.

Transformation

The process by which bacteria absorbs free plasmid DNA

The Central Dogma

Transcription Translation

Codons

Triplets of nucleotides that encode one amino acid

Helicase

Unwinds strands Unzipping the DNA helix

Mutations of DNA

can be detrimental or beneficial

Genome

the sum total of genetic material of a organism