Chapter 6 terms

Cell Biology - BIO211

DNA replication

a cell accurately copy the vast quanitiy of genetic information carried in DNA

Mutations

permanent changes in copying and repairing DNA

Complementary

partner strand to nucleotide sequence

Semiconservative

DNA double helicase ends up with one original (old) strand plus one new strand

Hydrogen bonds

stable, locked together bonds between bases on both strands of DNA double helices

Initiator proteins

begins DNA synthesis and binds to specific DNA sequences called replication origins

A-T base pair

held by 2 hydrogen bonds; easier to pull apart; found at replication sites

Replication forks

section where DNA replication takes place; created when helicase unwinds DNA; composed of a leading and lagging strand

Bidirectionally

DNA replication occurring in two different direction

DNA polymerase

catalyzes the addition of nucleotides of the 3’ end of the growing DNA strand; using an original DNA strand as the template; occurs in the 5’ to 3’ end

synthesis of proofreading

Deoxyribonucleoside triphosphate

contains 3 phosphate groups attached to the 5’ carbon of deoxyribose sugar of the nucleoside

Hydrolysis

a chemical reaction when a molecule of water breaks one or more chemical bonds

Polarity

one strand of DNA strand is being made on a template that runs in one template that runs in the opposite direction (3’ to 5’)

Backstitching maneuver

3’ to 5’ new strand is created

Complementary base-pairing

base pairs pair up with each other; A-T and G-C

Proofreading

DNA polymerase reads the newly added base before adding the next one so a correction can be made

Backstitching mechanism

maintaining the proofreading activity because the DNA polymerase operatin gin 3’ to 5’ direction would create a dead end

RNA

ribonucleic acid; DNA turns into RNA

RNA primase

joins a 10-nucleotide long RNA fragment

RNA polymerase

enzyme responsible for copying a DNA sequence into an RNA sequence during the process of transcription

Leading strand

RNA primase is at the beginning

Lagging strand

where DNA is discontinuous, new primers are continuously needed to keep polymerization going

Nuclease

needed to degrade the RNA primer

DNA polymerase I

needed to replace the RNA primer sequence

DNA polymerase II

DNA polymerase III

Ligase

Suspect copy

DNA helicases

DNA-binding protein

Topoisomerase

RNA primer

Telomere

DNA molecules

RNA template

Cell type

Depurination

Deamination

Thymine dimer

Nuclease

Repair DNA polymerase

DNA ligase

Mismatch repair

Replication machine

Mismatch

Double-strand break

Homologous recombination

Germ-line cell

Somatic cell

Cancer