2.5 Structure of mononucleotide, DNA and RNA. Complementary Base Pairing and hydrogen bonding in the formation of a DNA double helix.
Give an example of RNA
mRNA, tRNA, rRNA
What are DNA and RNA made up of?
nucleotides
Give an example of bases that are pyrimidines
Cytosine, thymine and uracil
How many polynucleotide strands make up RNA?
1, its single stranded
Name the 3 things each DNA nucleotide is formed from
1. A deoxyribose sugar with hydrogen 2. A phosphate group 3. One of 4 bases (A,C,G,T)
Name the 3 things each nucleotide is formed from
1. A pentose sugar 2. A base (nitrogen containing) 3. A phosphate group
Name the 3 things each RNA nucleotide is formed from
1. A ribose sugar with OH group 2. A phosphate group 3. One of 4 bases (A,C,G,U)
How many hydrogen bonds form between A and T?
2
What is a DNA pari
2 correct bases hydrogenly bonded together
How many hydrogen bonds form between C and G?
3
Each DNA nucleotide is said to have a X' and a Y' end. (Name the numbers that are X and Y)
3' and 5', these numbers relate to which carbon on the pentose sugar could be bonded with another nucleotide
When nucleotides join, what bond froms between where?
A phosphodiester bond forms the phosphate group of one nucleotide and a pentose sugar on the next nucleotide
Which bases are purines
Adenine and Guanine
Describe how the two DNA strands are arranged in a double helix
Antiparallel
Why do purine and pyrimidines link together (complementary base pairing)
Because there is the correct length between them for hydrogen bonds to form
What type of reaction cases nucleotides to form a polynuclotide?
Condensation reaction
Which polynucleotide strand is longer; DNA or RNA?
DNA
What is the difference in sugars between DNA and RNA
DNA has a dexyribose, RNA has a ribose sugar
Is DNA double or triple helix?
Double
What bonds holds the two antiparallel DNA polynucleotides strands together
Hydrogen bonds
What makes a base a pyrimidines
It has a single ring structure
Name the two structural forms that the nitrogenous base molecules occur as
Purines and Pyrimidines
What is the chain of alternating phosphate groups and pentose sugars called?
Sugar-phosphate backbone
What makes a base a purine?
The base has a double ring structure
How does the presence of the hydroxyl group on the RNA nucleotide change it's susceptibility to hydrolysis?
The presence of the 2' hydroxyl group makes RNA more susceptible to hydrolysis
Does DNA or RNA have a longer molecular lifespan? Why?
The presence of the 2' hydroxyl group makes RNA more susceptible to hydrolysis. This is why DNA is the storage molecule and RNA is the transport molecule with a shorter molecular lifespan
What base does RNA never contain?
Thymine, instead they have Uracil
What is the role of mRNA
Transcript copy of a gene that encodes a specific polypeptide
Define double helix
Two strands that spiral around each other
What is complementary base pairing?
When the correct purine forms hydrogen bonds with it's correct pyrimidine (A-t , C-G)