DNA (deoxyribonucleic acid) stores genetic information
RNA (ribonucleic acid) transfers genetic information from DNA to the ribosomes
Ribosomes formed from RNA and proteins
Nucleotide Structure
RNA
Ribose sugar
Phosphate group
1 of 4 different bases
Cytosine
Guanine
Adenine
Uracil
DNA
Pentose sugar
Phosphate group
1 of 4 different bases
cytosine
Guanine
Adenine
Thymine
Nucleotides Join together to form Polynucleotides
A dinucleotide is formed in a condensation reaction between the sugar of one
mononucleotide, and the phosphate group of another. The bond between them
is a PHOSPHODIESTER bond
Chain of sugars and phosphates = sugar-phosphate backbone
DNA Structure
2 DNA polynucleotide
stands join together by
hydrogen bonding between
the bases
2 H bonds
between
Adenine and
Thymine
3 H bonds between Cytosine
and Guanine
Each base only joins with
one partner -
complementary base
pairing
Adenine and Thymine
Cytosine and Guanine
Two antiparallel polynucleotide strands twist to form double helix