Chapter 4: Nucleic acids Flashcards
How many hydrogen bonds form between guanine and cytosine?
3
What must the two ends of a nucleic acid be labeled?
5’ and 3’
What are they 5 key components of DNA structure?
Double stranded, bases on opposite strands held together by hydrogen bonds, bases pair up in a specific manner, if you know the sequence of one strand you can figure out the other, and it is the specific sequence of bases that determines the order of amino acids in a polypeptide chain
What two pairs have to fit inside the double helix structure and why?
Purine-pyrimidine pairs are the only ones that fit. Purine-purine pairs are too big and pyrimidine-pyrimidine pairs are too small
Where do hydrogen bonds form in the DNA structure?
G-C pairs and A-T pairs
What happens during the condensation reaction when building a nucleic acid?
Phosphodiester linkages are formed between sugar and phosphate components of backbone
Where was the paper published that contained the DNA structure?
Nature in April 1953
What did Rosalind Franklin work with that proved DNA to be a double helix?
X-Ray Crystallography
What are the activated nucleotides for RNA and DNA?
Nucleoside triphosphates (NTPs) and Deoxynucleoside triphosphates (dNTPs)
What are some NTPs?
ATP, GTP, CTP, UTP (for RNA)
What is the shape of RNA?
Usually single stranded but sometimes folds back on itself when it gets long into the 2’ structure
What are the two types of nucleic acids?
Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)
What does RNA do?
It is necessary to translate the DNA instructions into proteins
Who was Rosalind Franklins boss that showed her photo of DNA to Watson and Crick without her consent?
Maurice Wilkins
What does deoxy mean in regards to DNA and RNA?
One less oxygen than RNA
What results in energy to be used?
The removal of two phosphates
What are the functions of RNA?
Protein synthesis, gene expression, catalyze rxns, genetic material (some viruses like HIV which is a retro virus)
Who was the first person to publish a structure of DNA but was wrong? Why was he wrong?
Linus Pauling. Three chains of negatively charged phosphates in the center would never work
What did Watson and Crick first propose for DNA structure and who told them they were wrong?
They proposed a triple helix and Rosalind Franklin told them it was wrong
What are the nitrogenous bases for DNA?
A, C, G, T
What are the nitrogenous bases for RNA?
A, C, G, U
Who received the Nobel Prize for the DNA structure and when?
Watson, Crick, and Wilkins in 1962
Who discovered the base components of DNA varies between species and the amount of A=T and the amount of C=G?
Erwin Chargaff (Chargaff’s rules 1950)
What does the creation of nucleic acids require?
Energy supplied by activated nucleotides (like ATP)
What are the components of RNA structure?
Ribose (has an extra -OH compared to DNA), unstable due to usually being single stranded, contains A, C, G, U, usually single stranded
What are the 3 parts of a nucleotide?
Nitrogenous base, 5-carbon sugar, and a phosphate group
What does DNA do?
Provides the instructions for life
What are the monomers of nucleic acids?
Nucleotides
How many hydrogen bonds form between adenine and thymine?
2
What is the difference between a purine and a pyrimidine?
The purines have two rings and the pyrimidines have one ring
What did Watson and Crick do to discover the structure of DNA?
They put everyones work together instead of doing the work
What direction do the two strands of DNA run?
Anit-parallel
What are some dNTPs?
dATP, dGTP, dTTP, dCTP (for DNA)
