Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
16 Cards in this Set
- Front
- Back
|
DNA and RNA are composed of?
|
nucleotides .
(1) a pentose sugar, (2) a nitrogenous base, (3) a phosphate group. |
|
|
Difference between the sugar backbone of a DNA and RNA?
|
RNA -- Ribose backbone (Hydroxyl group)
DNA -- Deoxyribose -- no hydroxyl group (where there is a hydroxyl in the RNA, there is a hydrogen in this one). |
|
|
Which carbons are the connecting ends for a polynucleotide?
|
5 ' and 3 '.
5 ' is the CH2, 3 ' is the OH. |
|
|
What links the nucleotides together?
|
The phosphate groups (phospho-di-ester bond).
**Rememeber, things start the 5 ', phosphate end, and end at the 3 ' OH group. |
|
|
Two types of nitrogenous bases?
|
Pyramidines (1 ring) or purines (2 rings).
|
|
|
And what are the resulting names? What differentiates them?
|
Adenine & Guanine are made from purines (Purines ... pure as silver, Ag).
Cytosine, Thymine (and uracil) are made from Pyrimidines (common Y to all of them). They're differentiated by their functional groups Adenine -- NH2 Guanine -- H2N & O Cytosine -- NH2 Uracil -- O Thymine -- O and Ch3? |
|
|
Examples of some nucleotides?
|
AMP -- Adenosine Monophosphate
GMP -- Guanosine monophosphate etc. When it's used in DNA, add 'd' in front for deoxy. as in dAMP (deoxy adenosine monophosphate). |
|
|
Before we knew that DNA was the genetic blueprint, what did we know?
|
DNA was made of 4 types of nucleic acids (A, G, C & T)
Protein was made of 20 different amino acids |
|
|
What did Fred Griffith accidentally discovering 1928?
What is that process called? |
that bacteria can take up genetic material from surroundings and incorporate it into their own genomes.
Bacterial transformation. |
|
|
How did Avery et al. follow up on that work?
|
isolate or enzymatically destroy each of the classes of macromolecules & test in
bacterial transformation experiments. Only intact nucleic acid transforms the bacteria That is, when you kill the bacteria strain (heat killed S-cells), but mix it with living R-cells, the mouse still dies.. the genetic material is being passed on through intact nucleic acids. |
|
|
Early evidence that viruses also use DNA as their genetic material?
|
Viruses pass on genetic material and have host cell replicate them.
|
|
|
How do viruses go about their business?
|
Bacterio-phage injects the host cell with it's genetic material. makes copies of itself in the host cell, and uses its metabolism to reproduce *** THEY'RE NOT TECHNICALLY ALIVE.
|
|
|
Hershey and Chase 1952 experiement?
|
Made either DNA
or protein radioactive |
|
|
Chargaff's rule?
|
proportionality. The # of A will always = # of T, and the # of G will always = # of C. ** Reason not understood until the discovery of the DNA double helix.
|
|
|
X-ray crystallography?
|
Pass x-ray through compound (DNA crystal in this case). Diffraction of x-rays gives some information on molecular structure.
The pattern that was revealed looked like a DNA double helix. They needed to explain this though. |
|
|
How did the double helix theory arrive?
|
Maurice Wilkins and Rosalind Franklin had the data, but couldn't resolve the structure ;.. showed the data to James Watson.
Watson and Crick proposed a double helix based on the purine and pyrimidine, bonded by hydrogen bonds. |
