10.1-10.3: The Structure of Genetic Material Flashcards
(13 cards)
Define molecular biology
the study of heredity at a molecular level (ie. nucleotide bases)
End of 10.1 Question: What convinced Alfred Hershey and Martha Chase that DNA, rather than protein, is the genetic material of bacteriophage T2?
Radioactively labeled phage DNA, but not labeled protein, entered the host cell during infection and directed the synthesis of new viruses (recall that viruses spread by infecting a host by inserting DNA and forcing that host to synthesize more viruses).
A polymer of DNA is also called a
polynucleotide
What are the three components of a nucleotide? How do nucleotides bond with each other?
a nitrogenous base, a phosphate group, and a sugar. There is a covalent bond between a sugar of one nucleotide and a phosphate of the next, creating the sugar-phosphate backbone of DNA.
What are the four bases? How do they pair up?
Thymine, cytosine, adenine and guanine. Cytosine and adenine have a NH2 group. Thymine and cytosine are single-carbon-ringed (pyrimidines). Adenine and guanine are double-carbon-ringed (purines). All bases are basic. Adenine goes with Thymine, cytosine with guanine.
What is the source of the work “acid” in nucleic acid?
The phosphate.
DNA and RNA have two separate sugars. What is the difference, and how do the names DNA and RNA tie in with it?
RNA molecules have an oxygen that DNA does not. They are appropriately named ribonucleic acid and deoxyribonucleic acid because the sugar is ribose, and within DNA it lacks an oxygen molecules.
What is the base that replaces Thymine in RNA? What is the chemical difference?
Uracil. Lacks a carbon and two hydrogens in nitrogenous base.
End of 10.2 Question: Compare and contrast DNA and RNA molecules.
Both are polymers of nucleotides consisting of a sugar, a nitrogenous base, and a phosphate. In RNA, the sugar is ribose, in DNA, the sugar is deoxyribose. Both RNA and DNA have the bases A,G, and C, but DNA has T and RNA has U.
(1952) What did the Hershey-Chase experiment convince most scientists?
That genetic information was found in the nucleotides of a cell, rather than the proteins.
Nitrogenous bases are linked through hydrogen bonds. How many hydrogens bonds does a C-G pair have? How about an A-T pair?
3;2
What did the Watson and Crick model of DNA suggest?
That DNA matched in certain pairs (other flashcards) and that those pairs arranged themselves in a double helix, which went on to be within chromosomes and connected Mendel’s genetics with molecular biology.
End of 10.3 Question: Along one strand of a double helix is the nucleotide sequence GGCATAGGT. What is the complementary sequence for the other DNA strand?
CCGTATCCA
