AP BIO module 5 key terms

Purine

Type of nitrogenous base with a double ring structure

Primidine

Nitrogenous base with single ring structure such as thymine cytosine and uracil

Thymine

Pyramid one vase found in DNA that pairs with Adenine

Cytosine

Pyrimidine base that pairs with guanine in both DNA and RNA

Directionality

Property of a nucleic acid strand where one end is chemically different from the other

Polarity

Synonym for directionality describing distinct 5’ and 3’ end of DNA and RNA

5’end

End of a nucleic acid strand that is the end that carries a free 5’ phosphate group

Nitrogenous Base

Cyclic molecule contains hydrogen carbon nitrogen and oxygen that services as the core component for a nucleotide

Adenine

Purine base found in both DNA and RNA that pairs with either thymine or uracil

Guanine

Purine base that pairs specifically with cytosine through three hydrogen bonds

3’ end

End of nucleic acid strand that is the end that carries a free 3’ hydroxyl group

Double Helix

Three dimensional shape of cellular DNA formed by two strands coiling around one another

Antiparallel

DNA strands that run in opposite directions meaning 5’ end of one strand faces the 3’ end of its partner

Complementary

Considered complementary when they form specific pairs like A with T and G with C across two strands

Uracil

Pyrimidine base found in RNA that replaces thymine and pairs with Adenine

Central Dogma

Defines flow of genetic information in a cell from DNA to RNA protein