CHapter 4 Flashcards
What are nucleic acids?
DNA and RNA
What is the three part structure of a nucleotide?
Phosphate group is bonded to a 5-Carbon sugar
Nitrogenous base.
What nucleotide that form rna?
Ribose
What nucleotide that form DNA?
deoxyribose
What’s the difference between a ribose and a deoxyribose?
deoxyribose.: Attached to carbon two is a hydrogen
ribose, attached to the carbon two is a hydroxide
What are the nitrogenous bases?
Cytosine, Uracil, Thymine, Guanine, Adenine
Out of the nitrogenous bases which ones can be used to form DNA? and RNA
Cytosine, Adenine, Guanine
Which of the nitrogenous bases are used to form only DNA?
Thymine
Which of the nitrogenous bases are used to form only RNA?
Uracil
What is the difference between the pyrimidines and the purines?
These are the two types of nitrogenous bases used to form nucleotides.
Purines: double hydro-carbon ring
Pyrimidines: Single hydro-carbon ring
What is the ribose problem?
In an experiment conducted to test the prebiotic earth it was found that most of the sugars formed in these environment are 6/3 carbon sugars, and it is quite difficult to get ribose to form here.
What is the pyridine problem?
In an experiment conducted to test the prebiotic earth
they found that it is much easier to get purines to form as opposed to pyrimdine
Nucleic acids are polymers of what?
nucleotides
When do condensation reactions occur?
anytime you make a biological polymer.
Describe the condensation reaction that takes place in nucleotides?
The hydroxide groups on the neighboring five prime phosphate group and 3 prime bond.
What is a phosphodiester linkage?
The bond between the hydroxides of the previous three prime carbons and phosphate groups
What is the result of breaking the phosphodiester bond?
You get a lot of potential energy
What is electrophoresis?
allows you to separate and study nucleic acids
What gives DNA a strong negative charge?
The phosphate groups are negatively charged
Who were the key members in the discovery of DNA?
Francis Crik, James Watson, Maurice Wilkins, Rosalind Franklin, Erwin Chargaff
What is DNA’s primary structure?
single linear strand
Describe the 3 prime and 5 prime ends of the DNA molecule?
5 prime end: phosphate group at the top, attached to it’s five prime carbon
3 prime end: hydroxide group at the bottom, it is attached to the 3 prime carbon
Why is the 3 prime and 5 prime ends of the DNA significant?
it makes the molecule polar, which is important for it’s structure.
What was Erwin Chargaff known for?
He compared the ratios of nucleotides of various organisms.
- He found the ratio of purines to pyrimidines, and adenine to thymine are both 1:1.
What was Maurice Wilkins and Rosalind Franklin known for?
DNA is a helix Mr White
What was Francis Crik and James Watson known for?
If you had two strands of DNA with purines opposite of one anther there two small to fit in the width of the DNA double helix.
If you have two strands of DNA with pyrimidine-pyrimidine on opposite sides it is too large for the space
- If you had a purine and a pyrimidine that is prefect for the space and they can form hydrogen bonds.
What is the difference between the major and minor groups of the DNA.
Major- proteins bind with specific sequences
Minor- proteins bind with whateva
Describe how DNA serves as a complementary strand?
with DNA splits in half it serves as a template to copy itself
What is the main structural differences between DNA and RNA?
RNA is not double stranded
Because RNA is single stranded what can it do structurally?
It can fold up to make a variety of secondary and tertiary structures
What are the varying functions of RNA, because of its ability to change into many vastly different shapes?
Some are information carries:
Some are structural:
Some are even catalytic:
Describe the process of RNA synthesis:
- ) complementary bases pair
- ) copied strand polymerizes
- ) copy and template separate
- ) copy serves as the new template
- ) new copy polymerizes
- ) New copy is identical to the original template
Is it possible for there to be a self-replicating RNA?
No, but we can generate self directed RNA replicators
How is RNA involved with making proteins?
RNA in ribosomes catalyzes peptide bond formation
What is the RNA world hypothesis?
RNA arised through chemical evolution and catalyze the formation of other complex molecules.
