Molecular Biology of the Gene

Vocabulary

Chargaff's rule

the rule that states that for double-stranded DNA, a relationship can be observed where the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine.

complementary strand

a strand of DNA that has complementary nitrogenous bases to another strand

deoxyribonucleic acid (DNA)

an organic molecule containing coded instructions for the life processes of an organism, which consists of nucleotides bonded together in the form of a double helix

DNA helicase

the enzyme in DNA replication that separates the two strands of the double helix by breaking the hydrogen bonds that hold them together

DNA polymerase

the enzyme in DNA replication that assembles the new strands of DNA from the template strands

excision repair

a mechanism used to repair a damaged section of DNA by removing the incorrect bases and replacing them with correct ones

genome

the genetic material of an organism

interphase

collectively the G1, S, and G2 phases of the cell cycle; in which a cell grows, replicates its DNA, and grows again

lagging strand

the strand of DNA that is synthesized in short segments during DNA replication

leading strand

the strand of DNA that is formed continuously during DNA replication

mismatch repair

the method of DNA repair that involves the scanning of the new strands after replication and correction of errors

mutation

a change in DNA sequence

purine

one of the two types of nitrogenous bases of nucleic acids, which consists of two joined rings containing carbon and nitrogen; includes adenine and guanine

pyrimidine

one of the two types of nitrogenous bases of nucleic acids, which consists of a single ring containing carbon and nitrogen; includes thymine, uracil, and cytosine

replication forks

the location on a replicating DNA molecule where the new strands will be produced

semi-conservative

the idea that each strand of DNA serves as a template for a new strand so that after replication, each molecule has one old and one new strand