Nucleotides

what is a nucleotide?

a monomer of nucleic acid which contains nitrogen

what are the 3 things all nucleotides are made up of?

• base containing nitrogen

• pentose sugar

• phosphate group

what is the sugar in DNA?

deoxyribose

what is the sugar in RNA?

ribose

what are the two purine bases?

• adenine (A)

• guanine (G)

what are purine bases?

bases that contain TWO nitrogen containing rings

what are the three pyrimidine bases?

• thymine (T)

• cytosine (C)

• uracil (U)

what are pyrimidine bases?

bases that contain only one nitrogen-containing ring

structure of adenine:

structure of guanine:

structure of thymine:

structure of cytosine:

structure of uracil:

which bases does DNA contain and which pair together?

T → A

C → G

which bases does RNA contain and which pair together?

U → A

C → G

how many hydrogen bonds are there between an Adenine and a Thymine?

2 hydrogen bonds

how many hydrogen bonds are there between a Cytosine and a Guanine?

3 hydrogen bonds

what is the bond needed to form polynucleotides?

phosphate - pentose carbon 3 bond

what are the two bonds in the formation of a nucleotide from a base, sugar and phosphate group?

• Pentose carbon 5 - phosphate bond

• Pentose carbon 1 - nitrogen base bond

which two carbons bond to the phosphate group on the pentose sugar?

carbon 3 - phosphate bond

carbon 5 - phosphate bond