DNA Flashcards
What does DNA stand for?
Deoxyribonucleic acid.
What does RNA stand for?
Ribonucleic acid.
What is the main function of RNA?
Transfer genetic information from the DNA to the ribosomes.
What is a nucleotide made from?
A pentose sugar, a nitrogen-containing organic base, a phosphate group
What’s it called when many nucleotides join together?
Polynucleotide strands
What type of reaction allows nucleotides to join up to make a polynucleotide strand?
A condensation reaction.
What is a phosphodiester bond?
A phosphate group and two ester bonds
What shape is DNA?
A double helix
What are DNA strands made up from?
Nucleotides (polynucleotide strands).
What is a DNA nucleotide made up from?
A phosphate group, deoxyribose (the pentose sugar), nitrogen-containing organic base.
What part of a DNA nucleotide can vary?
The nitrogen-containing organic base.
What are the four possible bases for a DNA nucleotide?
A (adenine), T (thymine), C (cytosine), G (guanine)
What type of bond joins two DNA polynucleotide strands together?
Hydrogen bonds
Which base is the complimentary base pair for A (adenine)?
T ( thymine)
What base is the complimentary base pair for T (thymine)?
A (adenine)
What base is the complimentary base pair for C (cytosine) ?
G (guanine)
What base is the complimentary base pair for G (guanine)?
C (cytosine)
What is an RNA nucleotide made up from?
A sugar, a phosphate group, one of four bases
What is the sugar in an RNA nucleotide?
A ribose sugar.
What are the four bases that can be on an RNA nucleotide?
A, U, C, G.
Are RNA strands or DNA strands longer in length?
DNA strands.
What does DNA helices do in DNA replication?
Breaks the hydrogen bonds between the bases of the two DNA strands.
In DNA replication, what happens once the base pair’s hydrogen bonds are broken?
The DNA helix unwinds and makes two single strands.
What happens in DNA replication once the two DNA strands are separated?
Free floating DNA is attracted to their exposed complimentary base pair on each original strand.
What does DNA polymerase do in DNA replication?
Joins complimentary bases together via a condensation reaction which makes a hydrogen bond form between the original strand and the new strand.
What is it called in DNA replication when each new DNA molecule is half original and half new?
Semi-conservative replication.
What are the two ends of DNA called?
3’ (prime) and 5’ (prime)
Which end of the DNA is the polymerase enzyme complimentary to?
3’ (prime)
What is Meselson’s and stahl’s experiment on semi-conservative DNA replication?
One bacteria is grown in light nitrogen, one is grown in heavy nitrogen. A sample was taken from each and spun, the DNA with heavy nitrogen settled lower than the light nitrogen because it’s heavier. The bacteria with the heavy nitrogen were taken out and put in a mixture with only light nitrogen; they were left for one replication, and then another DNA sample was taken and spun.
What would’ve happened to the heavy nitrogen DNA in meselson and stahl’s experiment if DNA replication was conservative?
The original heavy DNA would still be together and would have settled at the bottom and new light nitrogen DNA would have settled at the top
What would have happened in meselson an stahl’s experiment if DNA was semi-conservative?
The new DNA would have one strand containing light nitrogen and one strand containing heavy nitrogen. This would settle in the middle after being spun.
What were the findings of meselson and stahl’s experiment on DNA?
The mixed DNA settled in the middle after being spun which shows that it contained a mix of light and heavy nitrogen.
