Term
| What is the central dogma? |
|
Definition
|
|
Term
| Sequential phosphodiester bond formation proceeds in what direction? |
|
Definition
|
|
Term
| What were the 3 proposed models for DNA replication? |
|
Definition
| Semiconservative, Conservative, Dispersive |
|
|
Term
| Which experiment proved DNA replicated semiconservatively? |
|
Definition
| Meselson-Stahl which quantified the amount of 15N labeled DNA after several replication cycles. |
|
|
Term
| What are the percentages of isolated DNA for the first 3 replications in Meselson-Stahl? |
|
Definition
| 100% blended, 50% blended and 50% pure 14N, 25% blended and 75% pure 14N |
|
|
Term
| How many bands would have existed after the first replication if DNA replicated conservatively? dispersively? |
|
Definition
| 2, 1 gradually becoming less dense with each successive replication |
|
|
Term
| At what phase of the cell cycle does DNA replication occur? What is the primary enzyme that regulates this? |
|
Definition
| S Phase, Cyclin Dependent Kinase |
|
|
Term
| In eukaryotes replication initiates from _____ origins of replication and moves _____? |
|
Definition
| multiple, bidirectionally |
|
|
Term
| Since DNA synthesis cannot initiate de novo what must first occur? |
|
Definition
| primase lays down a temporary single stranded RNA primer (5 to 10 nucleotides long) |
|
|
Term
| Which strand requires multiple RNA primers? |
|
Definition
|
|
Term
[image]
What enzyme catalyzes this reaction? |
|
Definition
|
|
Term
| Initiator proteins are species specific. (T/F) |
|
Definition
|
|
Term
| What nucleases chew from the outside in? |
|
Definition
|
|
Term
| What nucleases cut like scissors inside DNA? |
|
Definition
| Endonucleases "restriction enzymes" |
|
|
Term
| With proofreading, DNA polymerase produces errors at what rate? |
|
Definition
| 1x10-7, one per 10 million necleotides. |
|
|
Term
| With mismatch repair what is the polymerase error rate? |
|
Definition
|
|
Term
| Nucleoside analogs that stop DNA replication lack (chain terminators)? |
|
Definition
|
|
Term
| What is the group of proteins at the replication forks called? |
|
Definition
|
|
Term
| Give 6 examples of DNA damage. |
|
Definition
| Mismatch (non WC), Depurination (removal of base), Pyrimidine dimer (UV light), Bulky adduct, Deamination (C -> U from nitrites in bacon), Alkylation (G), SSB, or DSB. DNA damage results in abnormal structure that can be detected and repaired by repair enzymes. |
|
|
Term
| Template independent DNA damage is performed by what enzymes (direct reversal)? |
|
Definition
| Pyrimidine dimers - photoactivation by photolyase, methylated Guanine - MGMT |
|
|
Term
| Single strand DNA damage where one intact copy is present can be fixed by what mechanisms? |
|
Definition
Base Excision Repair (BER) responsible primarily for removing small, non-helix-distorting base lesions from the
genome initiated by glycosylase and forms an AP site, Nucleotide Excision Repair (NER) recognizes and removes bulky helix-distorting lesions such as pyrimidine dimers, Mismatch Repair (MMR) |
|
|
Term
| How are double strand breaks created? repaired? |
|
Definition
Meiotic chromosome breaks, ionizing radiation, DNA replication errors or replication fork stresses
Repair is by homologous recombination or non-homologous end joining which is favored by humans but is more error prone. |
|
|
Term
| What are some DNA repair defect diseases? |
|
Definition
|
|
