Bio 202 Exam 3
Griffith's Transformation Experiment first described the bacterial ability to transfer genetic information through a
process called transformation - ability to kill is HERITABLE
Avery-MacLeod-McCarty experiment demonstrated that DNA is the genetic material because degradation of DNA led
to a stop of bacterial transformation
Hershey-Chase Experiment confirmed that DNA is the genetic material because only radiolabeled DNA could
be found in bacteriophage-infected bacteria
Chargaff's Rule [A]=[T] and [G]=[C], they pair up across from one another forming two strands
also called base pairing.
Primase An enzyme that joins RNA nucleotides to make the primer using the parental
DNA strand as a template.
DNA polymerase III synthesizes new DNA only in the 5' to 3' direction — can only add onto 3' end
Helicase An enzyme that untwists the double helix of DNA at the replication forks.
single stranded DNA binding proteins - bind to the unraveled strand preventing the re-association of the DNA strands &
degradation of DNA by nucleases
-Unpaired strands of DNA are very "sticky" so proteins are required to hold the 2
strands apart
Topiosomerase relieves overwinding strain ahead of replication forks by breaking, swiveling, and
rejoining DNA strands. relieves torsional strain (supercoiling) and untangles DNA
strands, acting as a molecular swivel ahead of the replication fork. By breaking
and rejoining DNA strands, it prevents DNA damage and knotting, allowing
replication to proceed smoothly.
DNA polymerase I Removes RNA nucleotides of primer from 5' end and replaces them with DNA
nucleotides added to 3' end of adjacent fragment
DNA ligase enzyme that chemically links DNA fragments together. A linking enzyme essential
for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA
fragment to the 5' end of a growing chain.
exonuclase activity the enzymatic process of removing nucleotides one at a time from the ends (3' or
5') of a polynucleotide chain by breaking phosphodiester bonds. It is crucial for
DNA proofreading (3'→5'), removing RNA primers during replication (5'→3'), and
repairing damaged DNA. DNA poly exhibits this.
Telomere repetitive DNA at the end of a eukaryotic chromosome
Telomere shortening chromosomes shorten every cell division. chromosome gets too short, cell dies
Telomerase An enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells.
Bound to an RNA template
, Bio 202 Exam 3
Okazaki fragment short segment of DNA synthesized discontinuously in small segments in the 3' to
5' direction by DNA polymerase
Lagging strand A discontinuously synthesized DNA strand that elongates by means of Okazaki
fragments, each synthesized in a 5' to 3' direction away from the replication fork.
Leading strand The new continuous complementary DNA strand synthesized along the template
strand in the mandatory 5' to 3' direction.
Nucleosomes negative DNA wrapped twice around positive histone proteins octomers.
Cell cycle series of events that cells go through as they grow and divide — reproduction,
growth, tissue renewal
Mitosis part of eukaryotic cell division during which the cell nucleus divides, producing
genetically identical daughter cells
Euchromatin The less condensed form of eukaryotic chromatin that is available for
transcription.
Heterochromatin Eukaryotic chromatin that remains highly compacted during interphase and is
generally not transcribed.— makes up centromere
Centromere Area where the chromatids of a chromosome are most closely attached
kinetochore A specialized region on the centromere that links each sister chromatid to the
mitotic spindle.
kinetochore microtubules Connects the centrosome with the kinetochore in the centromere region of the
chromosome.
Cytokinesis division of the cytoplasm to form two separate daughter cells
Interphase Cell grows, performs its normal functions, and prepares for division; consists of
G1, S, and G2 phases
G1 phase The first gap, or growth phase, of the cell cycle, consisting of the portion of
interphase before DNA synthesis begins. Metabolic activity, growth, organelle
replication.
S phase The synthesis phase of the cell cycle; the portion of interphase during which DNA
is replicated. Centrosomes are also replicated
Centrosomes Microtubule-organizing centers that help to form and organize the mitotic spindle
during mitosis — each contain two centrioles
Griffith's Transformation Experiment first described the bacterial ability to transfer genetic information through a
process called transformation - ability to kill is HERITABLE
Avery-MacLeod-McCarty experiment demonstrated that DNA is the genetic material because degradation of DNA led
to a stop of bacterial transformation
Hershey-Chase Experiment confirmed that DNA is the genetic material because only radiolabeled DNA could
be found in bacteriophage-infected bacteria
Chargaff's Rule [A]=[T] and [G]=[C], they pair up across from one another forming two strands
also called base pairing.
Primase An enzyme that joins RNA nucleotides to make the primer using the parental
DNA strand as a template.
DNA polymerase III synthesizes new DNA only in the 5' to 3' direction — can only add onto 3' end
Helicase An enzyme that untwists the double helix of DNA at the replication forks.
single stranded DNA binding proteins - bind to the unraveled strand preventing the re-association of the DNA strands &
degradation of DNA by nucleases
-Unpaired strands of DNA are very "sticky" so proteins are required to hold the 2
strands apart
Topiosomerase relieves overwinding strain ahead of replication forks by breaking, swiveling, and
rejoining DNA strands. relieves torsional strain (supercoiling) and untangles DNA
strands, acting as a molecular swivel ahead of the replication fork. By breaking
and rejoining DNA strands, it prevents DNA damage and knotting, allowing
replication to proceed smoothly.
DNA polymerase I Removes RNA nucleotides of primer from 5' end and replaces them with DNA
nucleotides added to 3' end of adjacent fragment
DNA ligase enzyme that chemically links DNA fragments together. A linking enzyme essential
for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA
fragment to the 5' end of a growing chain.
exonuclase activity the enzymatic process of removing nucleotides one at a time from the ends (3' or
5') of a polynucleotide chain by breaking phosphodiester bonds. It is crucial for
DNA proofreading (3'→5'), removing RNA primers during replication (5'→3'), and
repairing damaged DNA. DNA poly exhibits this.
Telomere repetitive DNA at the end of a eukaryotic chromosome
Telomere shortening chromosomes shorten every cell division. chromosome gets too short, cell dies
Telomerase An enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells.
Bound to an RNA template
, Bio 202 Exam 3
Okazaki fragment short segment of DNA synthesized discontinuously in small segments in the 3' to
5' direction by DNA polymerase
Lagging strand A discontinuously synthesized DNA strand that elongates by means of Okazaki
fragments, each synthesized in a 5' to 3' direction away from the replication fork.
Leading strand The new continuous complementary DNA strand synthesized along the template
strand in the mandatory 5' to 3' direction.
Nucleosomes negative DNA wrapped twice around positive histone proteins octomers.
Cell cycle series of events that cells go through as they grow and divide — reproduction,
growth, tissue renewal
Mitosis part of eukaryotic cell division during which the cell nucleus divides, producing
genetically identical daughter cells
Euchromatin The less condensed form of eukaryotic chromatin that is available for
transcription.
Heterochromatin Eukaryotic chromatin that remains highly compacted during interphase and is
generally not transcribed.— makes up centromere
Centromere Area where the chromatids of a chromosome are most closely attached
kinetochore A specialized region on the centromere that links each sister chromatid to the
mitotic spindle.
kinetochore microtubules Connects the centrosome with the kinetochore in the centromere region of the
chromosome.
Cytokinesis division of the cytoplasm to form two separate daughter cells
Interphase Cell grows, performs its normal functions, and prepares for division; consists of
G1, S, and G2 phases
G1 phase The first gap, or growth phase, of the cell cycle, consisting of the portion of
interphase before DNA synthesis begins. Metabolic activity, growth, organelle
replication.
S phase The synthesis phase of the cell cycle; the portion of interphase during which DNA
is replicated. Centrosomes are also replicated
Centrosomes Microtubule-organizing centers that help to form and organize the mitotic spindle
during mitosis — each contain two centrioles
