Learning Objectives Cell Bio #4

Describe how Griffith adn Avery/Maclead/McCarty experiments illustrate that DNA is genetic material

Griffith: S and r strain, when s strain heat killed and added to live (nonlethal) r strain, the mouse dies and live s strain found

Avery: modified to treat the killed s strain with DNase and protease before adding to r strain: mouse dies with protease and live s strain found; mouse lives with DNAse and live r strain found

• shows dna is genetic material

describe how hershey/chase experiment illustrates DNA as genetic material

32p has DNA, 35 S has protien. when virus and e coli mix the virus trasnfers genetic material - pellet=bactera (32P), supernatant=virus(32S)

• DNA is genetic material, not protein, because bacteria intakes the 32 P(DNA)

Define semi-conservative replication, how was it demonstrated in experiment?

one strand parent one strand daughter, shows by incubating in N15 for 24 hours, then transfering to N14 for 20 minutes, see only intermediate (50/50), after 40 min they see 1 N14, 1 intermediate (must be semi-conservative)

Why are RNA primers a necessary component of DNA replication

DNA polymerase needs an existing 3 OH group to build off of, and RNA polymerase doesn’t require a 5’ OH group

Describe role of each enzyme in DNA replication: Helicase, Single strand binding proteins, Primase, DNA Polymerase III, DNA Polymerase I, Ligase

Draw replication fork with 5” and 3’ end, leading and lagging strand, RNA primer locations, direction of DNA synthesis for daughter strand

What are telomeres, why are they nexessary in eukaryotes and how are they generated

describe how mutations may arise as a result of DNA replication, 3 mechanisms for how mutations can be fixed

How does RNA differ from DNA? Address the nucleotides and the nucleic acid

How does RNA differ from DNA? Address the nucleotides and the nucleic acid

Compare and contrast the processes of replication and transcription

Describe the role of each of the following in transcription initiation:

1. TATA box

2. Enhancers and Silencers

3. TFIID (in general)

4. TBP: specific role as part of TFIID

5. Mediator

6. RNA Pol Il