Biology: DNA structure and replication Flashcards
what are DNA and RNA are made up of _____________. What components does ____________ have?
nucleotide monomers.
5 carbon sugar, phosphate, and a nitrogenous base
what did gregor mendel do?
father of genetics, discovered that heritable factors were passed down from parent to offspring
what did thomas hunt morgan do?
proved genes are carried on chromosomes and are the mechanism of inheritance
what is the identity of genetic material
protein and DNA
Describe Frederick Griffith’s experiment
He had experimented with bacterium that causes pneumonia. He used a pathogenic and a nonpathogenic strain. He killed the pathogenic strain through heat and mixed the dead one with the nonpathogenic strain. He found out that the living cells and the future offsprings of the living ones became pathogenic. He called this transformation. He didn’t know what the transforming principle was tho
What is transformation?
change in genotype and phenotype due to the assimilation of foreign DNA by a cell
Avery McCarty Macloid experiment
they said the transforming principle from Griffith’s experiment was DNA. they isolated different solutions containing the heat killed S bacteria cells and examined which solutions transformation still occurred with the R bacteria strain. Solution of S strain DNA led to transformation of R strain. Many scientists didn’t believe this tho
Hershey and Chase experiment
showed DNA was the genetic material of bacteriophage (T2). They used radioisotopes of sulfur and phosphorus. Results showed that viruses transferred DNA, not proteins, into bacteria cells.
what is a bacteriophage?
a virus that infects bacteria
T2 viruses are composed of what
DNA and protein
what is the pentose (5 carbon) sugar found in DNA nucleotides
deoxyribose
what are the carbon atoms in the pentose sugar numbered?
1’ to 5’ (‘ = prime)
what is nitrogenous base bound to?
What is phosphate group bound to?
1’
5’
what are the two families of nitrogenous bases
pyrimidines and purines
pyramidines include what
cytosine, thymine, uracil
purines include what
adenine, and guanine
Thymine is found where?
Uracil is found where?
where are the others found?
DNA
RNA
Both
nucleotides are joined together by a series of ________ to form a strand called _______________
dehydration reactions, polynucleotide
covalent bonds are formed between the ____________ of one nucleotide and the phosphate group of the next nucleotide
3’ carbon
phosphodiester linkage
link between 3’ carbon of one nucleotide and the 5’ carbon of the next nucleotide
polynucleotides have two ends:
3’ end (hydroxyl) and 5’ end (phosphate)
where are nucleotides added during DNA and RNA synthesis
3’ end of the growing strand
Franklin and Wilkin’s contribution
used crystallography to study 3D structure of DNA. concluded that two outer sugar phosphate backbones, with the nitrogenous bases paired in the molecule’s interior, formed helical structure
Watson and Crick’s contribution
developed final model of DNA, added onto franklin and wilkin’s contribution, .
