Nucleic Acids Flashcards
What 3 components make a Nucleotide?
Phosphate head, Pentose sugar, Nitrogenous base
What are the 2 types of Pentose sugar for DNA and RNA?
o DNA - Deoxyribose
o RNA - Ribose
What bond is formed between phosphate and pentose sugar?
Ester bond
What are the names of the 4 Nitrogenous bases?
Adenine, Thymine, Cytosine, Guanine
What base replaces Thymine for RNA?
Uracil
What is the difference in structure between DNA and RNA?
o DNA contains a double helix whereas RNA is single stranded o DNA (deoxyribose) / RNA (ribose)
What bases make up the Purines?
Guanine and Adenine
What bases make up the Pyrimidines?
Cytosine, Thymine and Uracil
What is the role of mRNA?
To carry the complementary DNA code out of the nucleus to the ribosomes for protein synthesis.
What are the roles of Nucleotides?
o Synthesis and repair of nucleic acids
o Metabolic functions (e.g. synthesis of ATP)
What reaction happens when Polynucleotides are formed?
Condensation reaction between 5’ phosphate group of one nucleotide and 3’ hydroxyl group of the sugar of another group.
Where is a Phosphodiester bond formed?
The bond is formed between the O on the phosphate group and the 3’ on the pentose sugar (Water molecule used)
How many hydrogen bonds are formed between G and C and T and A base pairings?
o G+C = 3
o A+T = 2
What do the base pairs link to?
Sugar-phosphate backbone
How are two nucleotide chains joined together?
o Hydrogen bonding between complementary base pairs
o A&T and G&C bond together as a purine and pyrimidine both join
o 2H bonds between A&T and 3H bonds between C&G
