Nucleotide
DNA Consists of this material which is many repeating linked units. Each nucleotide has a sugar a phosphate and a base
DNA contains four cases
Cytosine guanine thymine and adenine
The amount of adenine is always equal to the amount of thymine
The amount of guanine is always equal to the amount of cytosine
Chargaffs rule
That a=t and c=g
X Ray diffraction
Where x Rays are beamed at a molecular and are reflected in a specific pattern that reveals aspects of the molecules structure
Nucleoside
a deoxyribose or ribose sugar and a base together are called this
Third composite of a nucleotide
A phosphate group which consists of a phosphorus atom bonded to four oxygen atoms
Phosphodiester bonds
Strong covalent bonds that link nucleotides in DNA
Polynucleotide strand
A series of nucleotides linked in a specific way with Phosphodiester linkages
B DNA
The DNA structure constructed by Watson and Crick with a right handed double helix with ten bases per turn
Transcription
When DNA Expresses the genetic material and transfers it to an RNA
Translation
When the RNA molecule transfers the genetic information to a protein by Specifying the amino acid sequence
Why do they call it translation
Because you go from the language of nucleotides from RNA to the language of amino acids for proteins
Hairpin
A common type of secondary structure found in single strands of nucleotides
Replication
When info is transferred from one DNA molecule to another
What does the stability of DNA allow us to do
it allows us to extract and analysis ancient DNA including Neanderthal bones that are almost 38,000 years old
Key characteristics of DNA
1. the genetic material must contain complex info
2. genetic material must replicate faithfully
3. genetic material must encode the phenotype as well as the genotype
4. genetic material must have the capacity to vary
1866
the year Mendel's work was first published
1900
Mendel's work is rediscovered by multiple groups whose experiments supported Mendel's old data
Late 1800's
Kossel determin3s that DNA contains nitrogenous bases
1944
Avery, MacLeod and McCarty demonstrate that the transforming principle is DNA
1948
Chargaff discovers regularity in base rations of DNA known as Chargaff's rule A=T and C=G
1953
Watson and Crick devise the secondary structure for DNA
1952
Hershey and Chase demonstrate that DNA is genetic material in bacteriophage so the world knew it wasn't protein
1928
Griffith's experiment with rough and smooth bacteria in mice demonstrates the transforming principle which is later known as DNA
1956
Fraenkel-Conrat and Singer show that some viruses use RNA as their genetic material
1910
Leven proposes the four nucleotide theory
What did Griffith's experiment prove
that the transforming principle also known as DNA, was the genetic material in bacteria which may cause transformations and be passed down to offspring
What is T2 and what does it infect
T2 is a bacteriophage which attacks E.Coli. T2 phage attach to the E.Coli and inject the chromsome. The bacterial chromsome breaks down and the phage chromsome replicates. The expression of phage genes produces more phages and progeny assemble. The bacter
1952 Hershey and Chase's Blender Experiment
provided final evidence that DNA was the genetic material of E.Coli phage T2. The main question needed to be answered is what part of the phage either DNA or protein serves as the genetic material that's transmitted to the phage progeny
What is a phage's genome made out of
it is made out of DNA
What are the parts of the bacteriophage made up of
it is made up of proteins
How does the blender experiment conducted by Hershey and Chase work
They tag the phage with 35 Sulfur which is taken up by the phage protein which contains sulfur but not Phosphorus. 32 phosphorus on the other hand is taken up in phage DNA which contains phophosrus not Sulfur. Both pages infect E.Coli. Now the protein coa
Which paper were Watson and Crick featured in
Nature. they showed insight on the 3D structure of DNA.Watson and Crick used simple paper cut outs of different nucleotides based on best chemical information known to create models of possible DNA structures
What was one thing Watson and Crick knew and used that other scientists didn't
that the phosphates shouldn't be places near each other because they are negative and should repel each other due to their similar charge
Adenine
Nucleotide: deoxyadenosine
5 prime monophosphate
Nucleotide symbol: dAMP
Nucleoside: deoxyadenosine
Nuceloside symbol: dA
Guanine
Nucleotide: deoxyguanosine, 5 prime monophosphate
Nucleotide Symbol: dGMP
Nucleoside: deoxyguanosine
Nucleoside symbol: dG
Cytosine
Nucleotide: deoxycytidine,5 prime monophosphate
Nucleotide Symbol dCMP
Nucleoside: deoxycytidine
Nucleoside symbol: dC
Thymine
Nucleotide: deoxythymidine, 5 prime monophosphate
Nucleotide Symbol: dTMP
Nucleoside: deoxythymidine
Nucleoside symbol: dT
pyrimidines
small, have two hydrogen bonds. Thymine and cytosine
purines
large, have three hydrogen bonds. Adenine and guanine
Rosalin Franlkins x-ray date of this helped Watson and Crick with constructing DNA structure
b-DNA x-ray diffraction data
Who proved that certain genomes are RNA not DNA in 1956
Freankel-Conrat and Singer's experiment showed that RNA in TMV carries the genetic information
Main features of B-DNA
1.the double helix is right handed
2.sugar phosphate backbone is formed through phosphodiester bonds
3. specific base pairing of AT and GC produce different numbers of hydrogen bonds
4. the complementary DNA strands are anti-parallel
5. there are ten turn
what is the DNA backbone made up of
deoxyribose sugars linked by phosphate
How many secondary structures can DNA have
several structures including A, B and Z form
Hairpin structure
in single strands of nucleotides when sequences of nucleotides on the same strand are inverted complements a hairpin structure forms
when the complementary sequences are contiguous(touching sharing a boundary) the hairpin has a stem but no tip
RNA molecul
special H-DNA structure can form in DNA
H-DNA is a three stranded also known as a triplex, formed when DNA unwinds and one strand pairs with double stranded DNA from another part of the molecule
- this often occurs in long sequences of only purines or of only pyrimidines
- common in mammalian g
The beta form of DNA
has oxygen, phosphorus, hydrogen, bases, and carbon in the sugar phosphate backbone
what is super coiling
when DNA wraps around itself
how long is DNA usually
about 2nm
what makes up chromatin
DNA and protein
how many bases are in a turn of the DNA
approximately 10.6
two types of protein
proteins that bind to specific nucleotides and proteins that bind to non-specific nucleotides
specific proteins
more important in genetics because they bind to specific nucleotides. The majority of proteins bind to the major groove because they can easily interact with the nucleotides and read them easily
non-specific proteins
less commonly found
Tata binding protein group
is the only one that binds to the minor grove. The protein can't easily interact with the nucleotides due to the structure of the minor groove
histones
bind non-specifically to forma bond
how do histones bind to DNA
they contain basic amino acids and have positive histone tails. these positively charged tails bind to the negatively charged phosphates in DNA
What does DNA do to an octamer of histones
it wraps around it tightly because the negative charges are attracted to the positive charges of the histone
How do you alter the positive charges on a histone
by using the process of acetylation. This is the addition of acetate to cover the positive tails so that the DNA slides
some scientists have found that acetylation or de-acetylation can cause
an increase or decrease in an organisms life either extending it to make it two times longer or making it half as long
is it b-form the only form of DNA
no, DNA can have several secondary structures such as b, h, and z form
DNA secondary hair pin structures are also called
stem and loop structures or just stem structures depending on the composition of the structure
Z-form DNA has a
left handed double helix
B- form of DNA has a
right handed double helix
A-form is
commonly found in nature
RNA can act as enzymes that are important in nature these are called
Ribozymes
only a few enzymes are
made up of RNA
an example of a Ribonuclear-protein-complex
a splicisome
what do hairpins do
they may attract proteins, or act as binding sites
tRNA
has many unusual nucleotide bases
H-DNA
has a triple helix or a triplex which unwinds at a certain spot. The genetic code differs from normal DNA
database
if you know the nucleotide sequence you can type it in and then they will send you the molecule for one dollar per nucleotide. they tried to use this to create drugs but were not successful
Which are more popular protein enzymes or RNA enzymes
protein enzymes
the type of enzyme that makes a peptide bond
a Ribozyme
Ribozyme is
a generic term that describes a protein made up of RNA which differs from a protein enzyme
There are about how many nucleotides per turn of the DNA Helix
10.6 nucleotides
Guanine and cytosine have how many hydrogen bonds
3
Thymine and adenine have how many hydrogen bonds
2
Where are the phosphate groups located on DNA
The five prime end
Hairpin structure
In single strands of nucleotides when sequences of nucleotides on the same strand are inverted compliments a hairpin structure is formed
When the complementary sequence are contiguous the hairpin has
A stem but no loop
Contiguous
neighboring, sharing, adjacent
DNA molecules may contain numerous hair pins allowing them to
Fold up into complex three d strictures
H DNA
Three stranded or triplex which is formed when DNA unwinds and one strand pairs with a double stranded DNA from another part of the molecule. This often occurs in long sequences of only purines or of only pyrimidines. Common in mammalian genomes
Hair pins
One common type of secondary structure found in single strands of nucleotides. Consists of a. Region of paired bases the dt and sometimes includes unpaired bases that make up the loop
When does a hairpin not have a loop
When the complementary strands or sequences are constant