before the enzyme

not really that clear

transcription takes dna to rna

translation takes rna to protein

reverse transcriptase

take rna to dna

the replication of dna is always

a. dispersive

b. conservative

c. semi conservative

1) separation of dna strands, unwinding the double helix and protecting the single strands of dna

2)synthesis of dna from 5' to 3'. (4 strands always being synthesized)

3)guard against errors in replication

replication forks, one at each end

=====<                  >=====

the 3'OH (nucleophile) attacks the 5'PPP

2PP leave and an OHP (phosphodiester bond is formed)

fxn of single stranded binding protein

SSB

polymerase I

repair and remove primers

class: topoisomerase

fxn: to remove super coils from dna so that it may unwind. works with helicase.

when a damaged base is recognized it is removed by dna glycosylase leaving an AP site. Apurin/apyrimidinic endonuclease severs dna.

excision nuclease removes a couple of nucleotides. dna pol I fills in gap and ligase seals the two dna strands.

origin recognition complex binds origin of replication. then replication activator protein binds. then replication licensing factors bind.

forming the pre replication complex.

polymerase subunits and fxn

beta

gamma

alpha

beta- sliding clamp

gamma- hold beta and alpha together

alpha- catalytic subunit

which is abundant during replication

pol III, polI, both

both

but usually pol I is the only abundant one

ABC casette repair

Cleaves at two site (endonuclease) then excises dna lesion.

ie tymidine dimer

In prokaryotes what is the promoter?

how is it located

where is it located

-10- pribnow box TATAAT

-35 region

the sigma subunit

upstream of the TSS on the mRNA

How is transcription stopped

3 ways

stop codon (UGA, UAA, UAG)

poly u tail with inverted repeats which stalls the rna polymerase then falls off

rho factor- which chases rna polymerase when it catches up it facilates disassociation

when lactose is present lac genes are synthesized

when lactose is not present then lac repressor is made and binds to the lac operator preventing the synthesis of the structural genes

leucine zipper

HTH

zinc finger

7 methyl guanosine at 5'

polyadenylation at 3'

splicing rna to remove introns

what percentage of proteins require chaperones?

how do proteins fold without chaperones?

discuss heat shock proteins.

15 %

hydrophobic interactions

Heat shock proteins are produced during heat stress they bind to newly synthesized proteins so that that they do not prematurely associated with e.o

how many codons

whats the ratio to trna

64

less trna because of the wobble binding

the sense strand has a_________codon

the trna has the ________codon

codon

anticodon

Bgalactosidase-fxn

permease

transacetylase

1)break down lactose

2)allows lactose to get in

3)no known official fxn

In eukaryotes what located the promoter (TATAA box)

- TFIID- also regulates level of transcription

where is the shine delagrno sequence located?

where does it bind in the ribosome?

the trna binding sites are located where?

on the mrna strand.

it binds to the 30s subunit.

in the 50s subunit.

5'AUG3'

 methionine

how does it apply to restrictive endonucleases

thats where the restrictive endonucleases cleave

A right handed helix. bp at 20* angle. artifact

B- natural. right handed helix. usual DNA

Z- left handed helix. zig zag appearance

(galactose (b1->4) glucose)

found in milk

made from starch

glucose a(1,4) glucose

storage form of starch in branched form with a(1,4) and a(1,6) linkages

less branched form of glucose storage

same linkages as glycogen