Lecture 4&5/01.22.25/01.25.25 Flashcards
(48 cards)
What are nucleic acids composed of(chemically)?
Organic nitrogenous bases, a pentose sugar, and phosphate
What are the two types of nucleic acids?
DNA(deoxyribonucleic acid) and RNA(ribonucleic acid)
What is the difference in ribose between DNA and RNA?
There is one ribose in RNA and 2 deoxyribose in DNA
What connects the polymeric chains?
covalent bonds
What is true about the acidity of a phosphate group? What about the pKa?
It is highly acidic with a pKa of 1
What is replaced in DNA that RNA doesn’t have?
There are 2 hydroxyl groups that are replaced by two H in DNA
What are the two purine bases in DNA?
adenine and guanine
What are the two pyrimidines in DNA?
cytosine and thymine
What are the purines in RNA?
Same as DNA which is adenine and guanine
What are the two pyrimidines in RNA?
cytosine and uracil
What is the difference between a nucleotide and a nucleoside?
A nucleoside has a base and sugar but no phosphate
How do nucleic acids turn into nucleotides?
They bond with other bases to form polynucleotides via the glycosidic bond
What is a special feature of RNA?
It has the presence of 2’ hydroxyl groups that are capable of catalyzing chemical reaction which allow for information storage and catalysis. It can act as enzyme and is known as a riozyme.
What is primary structure?
The linear order of nucleotides in polymeric nucleic acids. It also includes individuality.
What was the Avery, Macleod, and McCarty Experiment?
It was an experiment that found that pathogenic strains can be transferred tp non-pathogenic strains and make them pathogenic. This was known as “transformation” and was stable for many generations
What was the Hershey-Chase Experiment?
It was where bacteriophage was grown in radioactive sulfur and phosphorus. The radioactive phosphorus was transfered during infection and was sufficient to direct formation of new bacteriophage. New phage had phosphorus but no radioactive sulfur.
What was the evidence for 3D structure of DNA or Watson/Crick Experiment?
It was the use of the findings of Chargaff and the x-rays of Rosalind Franklin.
What is secondary structure?
The 3D arrangement of the nucleotide residues with respect to one another. They include repeat distance of 10 nucleotides, pitch of 3.4 mm, 0.34 nm between 2 nucleotides
What is tertiary structure?
It is the longer range interactions in three dimensions such as supercoiling
What stabilizes H bonds in secondary structures?
H bonds between purines and pyrimidines
What force interaction is involved in secondary structure?
Bases are stacked by van der waals forces
What were the findings of Erwin Chargaff?
He showed that base composition varied from organism to organism. He also showed that %A=%T and %G=%C. However, A was never the same as G or T to C
What access do minor/major grooves have?
It is the access to bases
What are the major grooves?
They are groove that faces the sugar backbone and is accessible to DNA binding proteins
