Nucleic Acids Structure

What is RNA?

ribonucleic acid

• single-stranded

• hydroxyl a 2’

• contains Uracil

What is DNA?

deoxyribonucleic acid

• double-stranded

• contains one less oxygen at 2’

• contains thymine

What are nucleic acids?

store and transmit genetic information

What is the structure of a nucleotide

• a 5-carbon sugar

• a nitrogenous base

• 1-3 phosphate groups

What carbon are the base and the phosphate(s) attached to?

• Carbon is attached to the 1’

• Phosphates are attached to 5’

What are the three phosphate groups?

1) monophosphate

2) diphosphate

3) triphosphate

Are phosphates positively or negatively charged?

they are negatively charged

What makes up a nucleoside?

a base and a sugar

what makes up a nucleotide?

a base, a sugar, and a phosphate

How are nucleotides named?

by combining the number of phosphate groups to the base-sugar name

What are the five universal bases? Which are purines? Which are pyrimidines?

Adenine (purine)

Guanine (purine

Cytosine (pyrimidine)

Thymine (pyrimidine)

Uracil (pyrimidine)

What links nucleotides together into a polynucleotide strand?

phosphodiester bonds

What does a triphosphate nucleotide react with?

the 3’ carbon

What charge does the sugar-phosphate backbone have?

negative charge

What is the polarity of a strand?

5’-3’

What functional groups are found at the 5’ and 3’ ends?

• The 5’ end has a phosphate

• The 3’ end has a hydroxyl

How is information stored in DNA?

information is stored in a sequence of nucleotides ONLY

What are the features of a DNA double helix

• double-stranded

• right-handed

• antiparallel

• complementary

How many hydrogen bonds are between base pairs

• Adenine and Thymine contain 2 hydrogen bonds

• Cytosine and Guanine contain 3 hydrogen bonds

What is the difference between a major groove and a minor groove?

The major groove is wider and deeper than the minor groove

What does antiparallel mean?

means that the two strands are oriented with opposite polarity

What can RNA form?

RNA can form stem-loop structures, which are antiparallel