Unit 1.2
WHAT IT IS DNA??????
The DNA molecule comes in a twisted ladder shape called a "double helix ". The rungs are made up of the different bases ; guanine, adenine, thymine, and cytosine or G, A, T, C. the rule for these bases are that A ( adenine) always pairs with T ( thymine) and G ( guanine ) is always paired with C(cytosine).Genes are made of DNA. One strand of our DNA Contains many genes. Our body needs many genes to operate the body. The body uses a
protein called HEMOGLOBIN to capture and carry oxygen. Proteins such as enzymes that produce pigment for the eye and keratin gene for growing hair and nails are also produced by genes. Within our bodies we have a lot of DNA that is compacted into units called chromosomes. Chromosomes are efficient storage units for DNA. Each human has 46 chromosomes. We get 23 chromosomes from each parent. There are 2 sex chromosomes that determine whether you are male or female. These chromosomes are labeled as "X" and "Y". Females do not have Y chromosomes, females have 2 "X" chromosomes. Proteins are the machines that make all living things function. Different Proteins work together to do tiny parts in a big system. Cells use information encoded in their genes, like a protein library, as a "blueprint" for making proteins. Heredity is the passing of traits from parents to child. A sperm and egg cells each have 23 chromosomes. When the sperm and egg join they create a single cell called a zygote which has 46 chromosomes. A trait is a notable feature or quality in someone. Traits are like genes they are passed down through parents to children. Each gene is a secion of DNA that determines a trait. Traits are in DNA thats why traits tend to run thorugh families. Such as eye color and facial simularties and disease.
protein called HEMOGLOBIN to capture and carry oxygen. Proteins such as enzymes that produce pigment for the eye and keratin gene for growing hair and nails are also produced by genes. Within our bodies we have a lot of DNA that is compacted into units called chromosomes. Chromosomes are efficient storage units for DNA. Each human has 46 chromosomes. We get 23 chromosomes from each parent. There are 2 sex chromosomes that determine whether you are male or female. These chromosomes are labeled as "X" and "Y". Females do not have Y chromosomes, females have 2 "X" chromosomes. Proteins are the machines that make all living things function. Different Proteins work together to do tiny parts in a big system. Cells use information encoded in their genes, like a protein library, as a "blueprint" for making proteins. Heredity is the passing of traits from parents to child. A sperm and egg cells each have 23 chromosomes. When the sperm and egg join they create a single cell called a zygote which has 46 chromosomes. A trait is a notable feature or quality in someone. Traits are like genes they are passed down through parents to children. Each gene is a secion of DNA that determines a trait. Traits are in DNA thats why traits tend to run thorugh families. Such as eye color and facial simularties and disease.
DNA
Rosalind Freanklin
Franklin excelled at science and attended one
of the few girls’ schools in London that taught physics and chemistry.
Franklins dads was against women getting a higher education and wanted her to be
a social worker. In 1938 she enrolled at Newnham College, Cambridge, graduation in 1941. Franklin held a graduate fellowship for a year then quit in 1942 to work for a British Coal
Utilization Research Association.
She made studies of carbon and graphite microstructures.
This was her basis for her doctorate in physical Chemistry. She earned
her doctorate from Cambridge University in 1945. Franklin meet Maurice Wilkins
at John Randall’s Randall’s laboratory. They led separate operations and
experiments but they both dealt with DNA. Wilkins misunderstood Franklins role
thinking she was a technical assistant. Even though Franklin was a girl she
persisted on the DNA project “X-ray Photographs of DNA.”
She came very close to solving DNA structure, but was beaten to
publication by Crich and Watson in part because of the friction between Wilkins and
herself. Wilkins showed a picture of crystallographic portraits to Watson
and it then became clear and he put it in an article. Franklin moved to J.D.
Bernal’s lab at Birkbeck College .
She studied work o tobacco mosaic virus. IN 1956 Rosalind Franklin was diagnosed
with cancer and died 2 years later.
Franklin excelled at science and attended one
of the few girls’ schools in London that taught physics and chemistry.
Franklins dads was against women getting a higher education and wanted her to be
a social worker. In 1938 she enrolled at Newnham College, Cambridge, graduation in 1941. Franklin held a graduate fellowship for a year then quit in 1942 to work for a British Coal
Utilization Research Association.
She made studies of carbon and graphite microstructures.
This was her basis for her doctorate in physical Chemistry. She earned
her doctorate from Cambridge University in 1945. Franklin meet Maurice Wilkins
at John Randall’s Randall’s laboratory. They led separate operations and
experiments but they both dealt with DNA. Wilkins misunderstood Franklins role
thinking she was a technical assistant. Even though Franklin was a girl she
persisted on the DNA project “X-ray Photographs of DNA.”
She came very close to solving DNA structure, but was beaten to
publication by Crich and Watson in part because of the friction between Wilkins and
herself. Wilkins showed a picture of crystallographic portraits to Watson
and it then became clear and he put it in an article. Franklin moved to J.D.
Bernal’s lab at Birkbeck College .
She studied work o tobacco mosaic virus. IN 1956 Rosalind Franklin was diagnosed
with cancer and died 2 years later.
Chargaff
Erwin Chargaff carried out a series of research that revealed
additional details about DNA molecules, such as primary chemical components and the way they joined with each other. The DNA molecule exists in the double helix. Oswald Avery and his colleagues wrote a paper at Rockfeller University. The paper was famous in 1944. The paper explained what genes are. The paper stated that genes are demonstrated the hereditary units which is composed of DNA. This paper inspired Chargaff to launch a research program that revolved
around chemistry of nucleic acids. He first set off to see if different species had different DNA. Separating and identifying small amounts of organic material Chargaff made 2 conclusive conclusions. His first conclusion was the composition of DNA varies among species. Simply saying nucleotides do not repeat. His second conclusion was that DNA, no matter what organism or tissue type it comes from, maintains certain properties,
even as its composition varies. His realization was that A=T and C=G, combined
with Rosalind Franklins and Maurice Wilkins findings. Watson and Crick played with molecules and thought perhaps a different atomic configuration would make a difference. The complementary bases now fit but the hydrogen bonds and also the structure from Chargaff’s rule fit perfectly. DNA is a double-stranded helix, with 2 strands connected by hydrogen bonds. A bases are always put together with Ts and Cs are always put together with Gs, which supports Chargaff’s rule.
Erwin Chargaff carried out a series of research that revealed
additional details about DNA molecules, such as primary chemical components and the way they joined with each other. The DNA molecule exists in the double helix. Oswald Avery and his colleagues wrote a paper at Rockfeller University. The paper was famous in 1944. The paper explained what genes are. The paper stated that genes are demonstrated the hereditary units which is composed of DNA. This paper inspired Chargaff to launch a research program that revolved
around chemistry of nucleic acids. He first set off to see if different species had different DNA. Separating and identifying small amounts of organic material Chargaff made 2 conclusive conclusions. His first conclusion was the composition of DNA varies among species. Simply saying nucleotides do not repeat. His second conclusion was that DNA, no matter what organism or tissue type it comes from, maintains certain properties,
even as its composition varies. His realization was that A=T and C=G, combined
with Rosalind Franklins and Maurice Wilkins findings. Watson and Crick played with molecules and thought perhaps a different atomic configuration would make a difference. The complementary bases now fit but the hydrogen bonds and also the structure from Chargaff’s rule fit perfectly. DNA is a double-stranded helix, with 2 strands connected by hydrogen bonds. A bases are always put together with Ts and Cs are always put together with Gs, which supports Chargaff’s rule.
Watson and Crick
In early 1950 the race to discover DNA was on. Graduate Francis
Crick and James Watson were interested and impressed by Pauling’s work.
Pauling’s work consisted of proteins take the shape of an alpha helix, spiraled
like a spring coil. Watson went to a lecture by Franklin on her work.
Afterwards Watson returned to Cambridge with a rather muddy recollection of the
facts Franklin had presented. Watson and Crick made a failed model, which
caused a stopping to further research on DNA. In 1953 Wilkins was upset and
showed Franklins work to Watson without her knowing or consent. Watson and
Crick took a crucial conceptual step. They made a suggestion that the molecule
was made of two chains of nucleotides. In each a helix as Franklin found.
Watson and crick showed that each strand of DNA molecule was template for the
other. Matching base pairs interlocked in the middle of the double helix to
keep the distance between the chains consent. The structure so perfectly fit
the experimental data that it was almost immediately accepted.
In early 1950 the race to discover DNA was on. Graduate Francis
Crick and James Watson were interested and impressed by Pauling’s work.
Pauling’s work consisted of proteins take the shape of an alpha helix, spiraled
like a spring coil. Watson went to a lecture by Franklin on her work.
Afterwards Watson returned to Cambridge with a rather muddy recollection of the
facts Franklin had presented. Watson and Crick made a failed model, which
caused a stopping to further research on DNA. In 1953 Wilkins was upset and
showed Franklins work to Watson without her knowing or consent. Watson and
Crick took a crucial conceptual step. They made a suggestion that the molecule
was made of two chains of nucleotides. In each a helix as Franklin found.
Watson and crick showed that each strand of DNA molecule was template for the
other. Matching base pairs interlocked in the middle of the double helix to
keep the distance between the chains consent. The structure so perfectly fit
the experimental data that it was almost immediately accepted.
DNA: Franklin, Crick, & Watson