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Inheritance
Molecular Basis of; chapter 16 Campbell 7e Biology key terms
term | definition |
---|---|
transformation | change in genotype and phenotype due to the assimilation of external DNA; horizontal gene transfer |
bacteriophages; phages | viruses that infect bacteria |
double helix | presence of two strands in DNA |
semiconservative model | is accepted today; says that one of strand of the parent molecule pairs with a newly synthesized strand |
origins of replication | where the replication of DNA begins |
replication fork | the end of a replication bubble, a "Y" shaped region where the new strands of DNA are elongating |
DNA polymerase | an enzyme that catalyzes the elongation of DNA at the replication fork |
leading strand | DNA is synthesized in the 5' to 3' direction toward replication fork; requires only the DNA polymerase III |
lagging strand | DNA is synthesized in 5' to 3' direction away from replication fork |
Ozaki fragments | the lagging strand is assembled in pieces named for their discoverer |
primer | the initial, short nucleotide chain that initiates DNA synthesis |
DNA ligase | an enzyme that binds Ozaki fragments together through dehydration |
primase | an enzyme that can start an RNA chain from scratch |
helicase | an enzyme that unwinds DNA at the replication fork |
topoisomerase | relieves the srain that is created as DNA is unwound |
single-strand binding protein | bind to the DNA strands to stabilize them until they are used as templates for new DNA synthesis |
mismatch repair | cells use special enzymes to fix incorrectly paired nucleotides |
nuclease | an enzyme that cuts DNA where repairs need to be made |
nucleotide excision repair | DNA polymerase and ligase repair the gap by this method |
telomeres | nucleotide sequences at the ends of DNA that protect it from eroding |
telomerase | an enzyme that catalyzes the lengthening of telomeres |