described the theory of transformation; mouse study with bacteria
Hershey and Chase Study
determined that DNA is the genetic material of inheritance; bacteriophage study
the idea that bacteria take up DNA from their environment;
a change in genotype and phenotype due to the assimilation of external DNA by a cell
virus that attacks bacteria
the bacteriophage that was used in the Hershey and Chase study
Components of Nucleic Acids
The components are:
4 Nitrogen Bases of DNA
4 Nitrogen Bases of RNA
1 ringed Nitrogen base
2 ringed Nitrogen base
x-ray diffraction crystalography photographer
In what phase does DNA replication take place?
S Phase...sister chromatids form
Semiconservative Model of DNA Replication
when a double helix replicates, each of the two daughter molecules will have one old strand, derived from the parent molecule and one newly made strand.
untwists the double helix at the replication forks
Single-Strand binding proteins
keeps strands of DNA from recombining, binds to and stabilizes single-stranded DNA until it can be used as a template
An Enzyme that breaks DNA strands allowing them to untwist them during replication
building block for nucleic acids
adds the RNA Primer; Synthesizes an RNA primer at 5 prime end of leading strand and of each Okazaki fragment of lagging strand
installs new nucleotids; catalyzes the snythesis of new DNA by adding nucleotides to a pre-existing chain.
little pieces of DNA on the lagging strand that patches DNA nucleotides.
DNA Polymerase I
Changes RNA nucleotides into DNA nucleotides
Joins partial strands together; joins 3' end of DNA that replaces primer to rest of leading strand and joins Okazaki fragments of lagging strand
Cuts out damaged parts of DNA
Molecules detect mismatched pairs and replace them with the correct pairs
Junk DNA at the ends of DNA strands
Wrote "Inborn errors of metabolism: was based on his research on a disease called "alkaptonuria or when urine turns black"
Avery, Macleod and McCarthy Study
Treated the DNA with two enzymes, a protease degrades proteins; DNAse degrades DNA.
The strand of the DNA double helix that is copied by a base pair complementary to make an RNA.
The original molecule; the parental double helix remains intact and an all-new copy is made.
Each strand of both daughter molecules contains a mixture of old and newly synthesized parts.
Helix Destabilizing Proteins
Keeps strands separate
Top end and bottom end are not parallel, 5 prime has phosphate end and 3 prime has an OH- end.
the smooth strand
the rough strand
and enzyme that adds segments to ends of molecules of DNA/seals the ends acts like bumpers.
highly alkaline proteins found in eukaryotic cells nuclei that package and order the DNA into structural units called nucleosomes
is the small region of a chromosome "petite"
is the large region of a chromosome
a region of DNA typically found near the middle of a chromosome where two identical sister chromatids come closest in contact.
microtubule strands connected to centromeres.
Adenine's bonding pair, "A"
Guanine's bonding pair, "G"
made of sugar, 1 nucleotide and 1 phosphate
DNA "double helix"
is antiparallel with a 5'prime end and a 3'prime end
Functions of DNA
Transcription (protein synthesis), Translation, Replication
In Eukaryotic chromosomal DNA molecules that have a special nucleotide sequence such as TTAGGG
a structure has two branching "prongs", each one made up of a single strand of DNA. These two strands serve as the template for the leading and lagging strands which will be created as DNA polymerase matches complementary nucleotides to the templates.
segments of repetitive DNA #13, 14, 15, 21 and 22
bead-like structures with 140 base pairs of DNA wrapped around a disc of eight histone proteins.
special proteins that help link mucleosomes together for communication and support
Proteins that bind to the segment of DNA that links neighboring beads.
is acidic, negatively charged and associated with postiviely charged histone proteins.
Meselson and Stahl
Models of Replication; Conservative, semiconservative, disruptive/dispersive
Beadle "Beets" and Tatum
Neurospora research, experiment on fungus and mold - "one gene one enzyme"